update

Reviewed-on: #7

AI_prompt.txt

@@ -12,3 +12,42 @@ Role: Principal Systems Architect & Lead Software Engineer.Objective: Implement
 
 
 
+Create a walkthrough for Julia service-A service sending a mix-content chat message to Julia service-B. the chat message must includes 
+
+
+
+
+
+
+I updated the following:
+- NATSBridge.jl. Essentially I add NATS_connection keyword and new publish_message function to support the keyword. 
+
+Use them and ONLY them as ground truth.
+
+Then update the following files accordingly:
+- architecture.md
+- implementation.md
+
+All API should be semantically consistent and naming should be consistent across the board.
+
+
+
+
+
+
+
+
+
+Task: Update NATSBridge.js to reflect recent changes in NATSBridge.jl and docs
+
+Context: NATSBridge.jl and docs has been updated.
+
+Requirements:
+
+Source of Truth: Treat the updated NATSBridge.jl and docs as the definitive source.
+API Consistency: Ensure the Main Package API (e.g., smartsend(), publish_message()) uses consistent naming across all three supported languages.
+Ecosystem Variance: Low-level native functions (e.g., NATS.connect(), JSON.read()) should follow the conventions of the specific language ecosystem and do not require cross-language consistency.
+
+
+
+

Manifest.toml

@@ -1,8 +1,8 @@
 # This file is machine-generated - editing it directly is not advised
 
-julia_version = "1.12.4"
+julia_version = "1.12.5"
 manifest_format = "2.0"
-project_hash = "be1e3c2d8b7f4f0ee7375c94aaf704ce73ba57b9"
+project_hash = "b632f853bcf5355f5c53ad3efa7a19f70444dc6c"
 
 [[deps.AliasTables]]
 deps = ["PtrArrays", "Random"]
@@ -436,6 +436,12 @@ git-tree-sha1 = "d9d9a189fb9155a460e6b5e8966bf6a66737abf8"
 uuid = "55e73f9c-eeeb-467f-b4cc-a633fde63d2a"
 version = "0.1.0"
 
+[[deps.NATSBridge]]
+deps = ["Arrow", "DataFrames", "Dates", "GeneralUtils", "HTTP", "JSON", "NATS", "PrettyPrinting", "Revise", "UUIDs"]
+path = "."
+uuid = "f2724d33-f338-4a57-b9f8-1be882570d10"
+version = "0.4.1"
+
 [[deps.NanoDates]]
 deps = ["Dates", "Parsers"]
 git-tree-sha1 = "850a0557ae5934f6e67ac0dc5ca13d0328422d1f"

Plik_API_document.md

@@ -1,194 +0,0 @@
-### API
-Plik server expose a REST-full API to manage uploads and get files :
-
-Get and create upload :
- 
-   - **POST**        /upload
-     - Params (json object in request body) :
-      - oneshot (bool)
-      - stream (bool)
-      - removable (bool)
-      - ttl (int)
-      - login (string)
-      - password (string)
-      - files (see below)
-     - Return :
-         JSON formatted upload object.
-         Important fields :
-           - id (required to upload files)
-           - uploadToken (required to upload/remove files)
-           - files (see below)
-
-   For stream mode you need to know the file id before the upload starts as it will block.
-   File size and/or file type also need to be known before the upload starts as they have to be printed 
-   in HTTP response headers.
-   To get the file ids pass a "files" json object with each file you are about to upload.
-   Fill the reference field with an arbitrary string to avoid matching file ids using the fileName field.
-   This is also used to notify of MISSING files when file upload is not yet finished or has failed.
-  ```
-  "files" : [
-    {
-      "fileName": "file.txt",
-      "fileSize": 12345,
-      "fileType": "text/plain",
-      "reference": "0"
-    },...
-  ]
-  ```
-  
-   - **GET** /upload/:uploadid:
-     - Get upload metadata (files list, upload date, ttl,...)
-
-Upload file :
-
-   - **POST** /$mode/:uploadid:/:fileid:/:filename:
-     - Request body must be a multipart request with a part named "file" containing file data.
-
-   - **POST** /file/:uploadid:
-     - Same as above without passing file id, won't work for stream mode.
-     
-   - **POST** /:
-     - Quick mode, automatically create an upload with default parameters and add the file to it.
-
-Get file :
-
-  - **HEAD** /$mode/:uploadid:/:fileid:/:filename:
-    - Returns only HTTP headers. Useful to know Content-Type and Content-Length without downloading the file. Especially if upload has OneShot option enabled.
-
-  - **GET**  /$mode/:uploadid:/:fileid:/:filename:
-    - Download file. Filename **MUST** match. A browser, might try to display the file if it's a jpeg for example. You may try to force download with ?dl=1 in url.
-
-  - **GET**  /archive/:uploadid:/:filename:
-    - Download uploaded files in a zip archive. :filename: must end with .zip
-
-Remove file :
-
-   - **DELETE** /$mode/:uploadid:/:fileid:/:filename:
-     - Delete file. Upload **MUST** have "removable" option enabled.
-
-Show server details :
-
-   - **GET** /version
-     - Show plik server version, and some build information (build host, date, git revision,...)
-
-   - **GET** /config
-     - Show plik server configuration (ttl values, max file size, ...)
-
-   - **GET** /stats
-     - Get server statistics ( upload/file count, user count, total size used )
-     - Admin only
-
-User authentication :
-
-   - 
-   Plik can authenticate users using Google and/or OVH third-party API.   
-   The /auth API is designed for the Plik web application nevertheless if you want to automatize it be sure to provide a valid
-   Referrer HTTP header and forward all session cookies.   
-   Plik session cookies have the "secure" flag set, so they can only be transmitted over secure HTTPS connections.   
-   To avoid CSRF attacks the value of the plik-xsrf cookie MUST be copied in the X-XSRFToken HTTP header of each
-   authenticated request.   
-   Once authenticated a user can generate upload tokens. Those tokens can be used in the X-PlikToken HTTP header used to link
-   an upload to the user account. It can be put in the ~/.plikrc file of the Plik command line client.   
-   
-   - **Local** :
-      - You'll need to create users using the server command line
-   
-   - **Google** :
-      - You'll need to create a new application in the [Google Developper Console](https://console.developers.google.com)
-      - You'll be handed a Google API ClientID and a Google API ClientSecret that you'll need to put in the plikd.cfg file
-      - Do not forget to whitelist valid origin and redirect url ( https://yourdomain/auth/google/callback ) for your domain
-   
-   - **OVH** :
-      - You'll need to create a new application in the OVH API : https://eu.api.ovh.com/createApp/
-      - You'll be handed an OVH application key and an OVH application secret key that you'll need to put in the plikd.cfg file
-
-   - **GET** /auth/google/login
-      - Get Google user consent URL. User have to visit this URL to authenticate
-
-   - **GET** /auth/google/callback
-     - Callback of the user consent dialog
-     - The user will be redirected back to the web application with a Plik session cookie at the end of this call
-
-   - **GET** /auth/ovh/login
-     - Get OVH user consent URL. User have to visit this URL to authenticate
-     - The response will contain a temporary session cookie to forward the API endpoint and OVH consumer key to the callback
-
-   - **GET** /auth/ovh/callback
-     - Callback of the user consent dialog. 
-     - The user will be redirected back to the web application with a Plik session cookie at the end of this call
-
-   - **POST** /auth/local/login
-     - Params :
-       - login : user login
-       - password : user password
-
-   - **GET** /auth/logout
-     - Invalidate Plik session cookies
-
-   - **GET** /me
-     - Return basic user info ( ID, name, email ) and tokens
-
-   - **DELETE** /me
-     - Remove user account.
-
-   - **GET** /me/token
-     - List user tokens
-      - This call use pagination
-
-   - **POST** /me/token
-     - Create a new upload token
-     - A comment can be passed in the json body
-
-   - **DELETE** /me/token/{token}
-     - Revoke an upload token
-
-   - **GET** /me/uploads
-     - List user uploads
-     - Params :
-        - token : filter by token
-      - This call use pagination
-
-   - **DELETE** /me/uploads
-     - Remove all uploads linked to a user account
-     - Params :
-        - token : filter by token
-
-   - **GET** /me/stats
-     - Get user statistics ( upload/file count, total size used )
-
-   - **GET** /users
-     - List all users
-     - This call use pagination
-     - Admin only 
-
-QRCode :
-
-   - **GET** /qrcode
-     - Generate a QRCode image from an url
-     - Params :
-        - url  : The url you want to store in the QRCode
-        - size : The size of the generated image in pixels (default: 250, max: 1000)
-
-
-$mode can be "file" or "stream" depending if stream mode is enabled. See FAQ for more details.
-
-Examples :
-```sh
-Create an upload (in the json response, you'll have upload id and upload token)
-$ curl -X POST http://127.0.0.1:8080/upload
-
-Create a OneShot upload
-$ curl -X POST -d '{ "OneShot" : true }' http://127.0.0.1:8080/upload
-
-Upload a file to upload
-$ curl -X POST --header "X-UploadToken: M9PJftiApG1Kqr81gN3Fq1HJItPENMhl" -F "file=@test.txt" http://127.0.0.1:8080/file/IsrIPIsDskFpN12E
-
-Get headers
-$ curl -I http://127.0.0.1:8080/file/IsrIPIsDskFpN12E/sFjIeokH23M35tN4/test.txt
-HTTP/1.1 200 OK
-Content-Disposition: filename=test.txt
-Content-Length: 3486
-Content-Type: text/plain; charset=utf-8
-Date: Fri, 15 May 2015 09:16:20 GMT
-
-```

Project.toml

@@ -1,8 +1,21 @@
+name = "NATSBridge"
+uuid = "f2724d33-f338-4a57-b9f8-1be882570d10"
+version = "0.4.3"
+authors = ["narawat <narawat@gmail.com>"]
+
 [deps]
 Arrow = "69666777-d1a9-59fb-9406-91d4454c9d45"
+Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
+DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 GeneralUtils = "c6c72f09-b708-4ac8-ac7c-2084d70108fe"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
 NATS = "55e73f9c-eeeb-467f-b4cc-a633fde63d2a"
+PrettyPrinting = "54e16d92-306c-5ea0-a30b-337be88ac337"
+Revise = "295af30f-e4ad-537b-8983-00126c2a3abe"
 UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
+
+[compat]
+Base64 = "1.11.0"
+JSON = "1.4.0"

docs/IMPLEMENTATION.md

@@ -1,321 +0,0 @@
-# Implementation Guide: Bi-Directional Data Bridge
-
-## Overview
-
-This document describes the implementation of the high-performance, bi-directional data bridge between Julia and JavaScript services using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
-
-## Architecture
-
-The implementation follows the Claim-Check pattern:
-
-```
-┌─────────────────────────────────────────────────────────────────────────┐
-│                         SmartSend Function                              │
-└─────────────────────────────────────────────────────────────────────────┘
-                             │
-                             ▼
-┌─────────────────────────────────────────────────────────────────────────┐
-│  Is payload size < 1MB?                                                 │
-└─────────────────────────────────────────────────────────────────────────┘
-                             │
-           ┌─────────────────┴─────────────────┐
-           ▼                                   ▼
-     ┌─────────────────┐                 ┌─────────────────┐
-     │  Direct Path    │                 │  Link Path      │
-     │  (< 1MB)        │                 │  (> 1MB)        │
-     │                 │                 │                 │
-     │ • Serialize to  │                 │ • Serialize to  │
-     │   IOBuffer      │                 │   IOBuffer      │
-     │ • Base64 encode │                 │ • Upload to     │
-     │ • Publish to    │                 │   HTTP Server   │
-     │   NATS          │                 │ • Publish to    │
-     │                 │                 │   NATS with URL │
-     └─────────────────┘                 └─────────────────┘
-```
-
-## Files
-
-### Julia Module: [`src/julia_bridge.jl`](../src/julia_bridge.jl)
-
-The Julia implementation provides:
-
-- **[`MessageEnvelope`](../src/julia_bridge.jl)**: Struct for the unified JSON envelope
-- **[`SmartSend()`](../src/julia_bridge.jl)**: Handles transport selection based on payload size
-- **[`SmartReceive()`](../src/julia_bridge.jl)**: Handles both direct and link transport
-
-### JavaScript Module: [`src/js_bridge.js`](../src/js_bridge.js)
-
-The JavaScript implementation provides:
-
-- **`MessageEnvelope` class**: For the unified JSON envelope
-- **[`SmartSend()`](../src/js_bridge.js)**: Handles transport selection based on payload size
-- **[`SmartReceive()`](../src/js_bridge.js)**: Handles both direct and link transport
-
-## Installation
-
-### Julia Dependencies
-
-```julia
-using Pkg
-Pkg.add("NATS")
-Pkg.add("Arrow")
-Pkg.add("JSON3")
-Pkg.add("HTTP")
-Pkg.add("UUIDs")
-Pkg.add("Dates")
-```
-
-### JavaScript Dependencies
-
-```bash
-npm install nats.js apache-arrow uuid base64-url
-```
-
-## Usage Tutorial
-
-### Step 1: Start NATS Server
-
-```bash
-docker run -p 4222:4222 nats:latest
-```
-
-### Step 2: Start HTTP File Server (optional)
-
-```bash
-# Create a directory for file uploads
-mkdir -p /tmp/fileserver
-
-# Use any HTTP server that supports POST for file uploads
-# Example: Python's built-in server
-python3 -m http.server 8080 --directory /tmp/fileserver
-```
-
-### Step 3: Run Test Scenarios
-
-```bash
-# Scenario 1: Command & Control (JavaScript sender)
-node test/scenario1_command_control.js
-
-# Scenario 2: Large Arrow Table (JavaScript sender)
-node test/scenario2_large_table.js
-
-# Scenario 3: Julia-to-Julia communication
-# Run both Julia and JavaScript versions
-julia test/scenario3_julia_to_julia.jl
-node test/scenario3_julia_to_julia.js
-```
-
-## Usage
-
-### Scenario 1: Command & Control (Small JSON)
-
-#### JavaScript (Sender)
-```javascript
-const { SmartSend } = require('./js_bridge');
-
-const config = {
-    step_size: 0.01,
-    iterations: 1000
-};
-
-await SmartSend("control", config, "json", {
-    correlationId: "unique-id"
-});
-```
-
-#### Julia (Receiver)
-```julia
-using NATS
-using JSON3
-
-# Subscribe to control subject
-subscribe(nats, "control") do msg
-    env = MessageEnvelope(String(msg.data))
-    config = JSON3.read(env.payload)
-    
-    # Execute simulation with parameters
-    step_size = config.step_size
-    iterations = config.iterations
-    
-    # Send acknowledgment
-    response = Dict("status" => "Running", "correlation_id" => env.correlation_id)
-    publish(nats, "control_response", JSON3.stringify(response))
-end
-```
-
-### Scenario 2: Deep Dive Analysis (Large Arrow Table)
-
-#### Julia (Sender)
-```julia
-using Arrow
-using DataFrames
-
-# Create large DataFrame
-df = DataFrame(
-    id = 1:10_000_000,
-    value = rand(10_000_000),
-    category = rand(["A", "B", "C"], 10_000_000)
-)
-
-# Send via SmartSend with type="table"
-await SmartSend("analysis_results", df, "table");
-```
-
-#### JavaScript (Receiver)
-```javascript
-const { SmartReceive } = require('./js_bridge');
-
-const result = await SmartReceive(msg);
-
-// Use table data for visualization with Perspective.js or D3
-const table = result.data;
-```
-
-### Scenario 3: Live Binary Processing
-
-#### JavaScript (Sender)
-```javascript
-const { SmartSend } = require('./js_bridge');
-
-// Capture binary chunk
-const binaryData = await navigator.mediaDevices.getUserMedia({ binary: true });
-
-await SmartSend("binary_input", binaryData, "binary", {
-    metadata: {
-        sample_rate: 44100,
-        channels: 1
-    }
-});
-```
-
-#### Julia (Receiver)
-```julia
-using WAV
-using DSP
-
-# Receive binary data
-function process_binary(data)
-    # Perform FFT or AI transcription
-    spectrum = fft(data)
-    
-    # Send results back (JSON + Arrow table)
-    results = Dict("transcription" => "sample text", "spectrum" => spectrum)
-    await SmartSend("binary_output", results, "json")
-end
-```
-
-### Scenario 4: Catch-Up (JetStream)
-
-#### Julia (Producer)
-```julia
-using NATS
-
-function publish_health_status(nats)
-    jetstream = JetStream(nats, "health_updates")
-    
-    while true
-        status = Dict("cpu" => rand(), "memory" => rand())
-        publish(jetstream, "health", status)
-        sleep(5)  # Every 5 seconds
-    end
-end
-```
-
-#### JavaScript (Consumer)
-```javascript
-const { connect } = require('nats');
-
-const nc = await connect({ servers: ['nats://localhost:4222'] });
-const js = nc.jetstream();
-
-// Request replay from last 10 minutes
-const consumer = await js.pullSubscribe("health", { 
-    durable_name: "catchup",
-    max_batch: 100,
-    max_ack_wait: 30000
-});
-
-// Process historical and real-time messages
-for await (const msg of consumer) {
-    const result = await SmartReceive(msg);
-    // Process the data
-    msg.ack();
-}
-```
-
-## Configuration
-
-### Environment Variables
-
-| Variable | Default | Description |
-|----------|---------|-------------|
-| `NATS_URL` | `nats://localhost:4222` | NATS server URL |
-| `FILESERVER_URL` | `http://localhost:8080/upload` | HTTP file server URL |
-| `SIZE_THRESHOLD` | `1_000_000` | Size threshold in bytes (1MB) |
-
-### Message Envelope Schema
-
-```json
-{
-  "correlation_id": "uuid-v4-string",
-  "type": "json|table|binary",
-  "transport": "direct|link",
-  "payload": "base64-encoded-string",  // Only if transport=direct
-  "url": "http://fileserver/path/to/data",  // Only if transport=link
-  "metadata": {
-    "content_type": "application/octet-stream",
-    "content_length": 123456,
-    "format": "arrow_ipc_stream"
-  }
-}
-```
-
-## Performance Considerations
-
-### Zero-Copy Reading
-- Use Arrow's memory-mapped file reading
-- Avoid unnecessary data copying during deserialization
-- Use Apache Arrow's native IPC reader
-
-### Exponential Backoff
-- Maximum retry count: 5
-- Base delay: 100ms, max delay: 5000ms
-- Implemented in both Julia and JavaScript implementations
-
-### Correlation ID Logging
-- Log correlation_id at every stage
-- Include: send, receive, serialize, deserialize
-- Use structured logging format
-
-## Testing
-
-Run the test scripts:
-
-```bash
-# Scenario 1: Command & Control (JavaScript sender)
-node test/scenario1_command_control.js
-
-# Scenario 2: Large Arrow Table (JavaScript sender)
-node test/scenario2_large_table.js
-```
-
-## Troubleshooting
-
-### Common Issues
-
-1. **NATS Connection Failed**
-   - Ensure NATS server is running
-   - Check NATS_URL configuration
-
-2. **HTTP Upload Failed**
-   - Ensure file server is running
-   - Check FILESERVER_URL configuration
-   - Verify upload permissions
-
-3. **Arrow IPC Deserialization Error**
-   - Ensure data is properly serialized to Arrow format
-   - Check Arrow version compatibility
-
-## License
-
-MIT

etc.jl

@@ -1,42 +1,9 @@
+Task: Update README.md to reflect recent changes in NATSbridge package.
 
-""" fileServerURL = "http://192.168.88.104:8080"
-filepath = "/home/ton/docker-apps/sendreceive/image/test.zip"
-filename = basename(filepath)
-filebytes = read(filepath)
+Context: the package has been updated with the NATS_connection keyword and the publish_message function.
 
-plik_oneshot_upload - Upload a single file to a plik server using one-shot mode
+Requirements:
 
-This function uploads a raw byte array to a plik server in one-shot mode (no upload session).
-It first creates a one-shot upload session by sending a POST request with `{"OneShot": true}`,
-retrieves an upload ID and token, then uploads the file data as multipart form data using the token.
-
-The function handles the entire flow:
-1. Obtains an upload ID and token from the server
-2. Uploads the provided binary data as a file using the `X-UploadToken` header
-3. Returns identifiers and download URL for the uploaded file
-
-# Arguments:
-  - `fileServerURL::String` - Base URL of the plik server (e.g., `"http://192.168.88.104:8080"`)
-  - `filename::String` - Name of the file being uploaded
-  - `data::Vector{UInt8}` - Raw byte data of the file content
-
-# Return:
-  - A named tuple with fields:
-    - `uploadid::String` - ID of the one-shot upload session
-    - `fileid::String` - ID of the uploaded file within the session
-    - `downloadurl::String` - Full URL to download the uploaded file
-
-# Example
-```jldoctest
-using HTTP, JSON
-
-# Example data: "Hello" as bytes
-data = collect("Hello World!" |> collect |> CodeUnits |> collect)
-
-# Upload to local plik server
-result = plik_oneshot_upload("http://192.168.88.104:8080", "hello.txt", data)
-
-# Download URL for the uploaded file
-println(result.downloadurl)
-```
-"""
+Source of Truth: Treat the updated NATSbridge code as the definitive source. Update README.md to align exactly with these changes.
+API Consistency: Ensure the Main Package API (e.g., smartsend(), publish_message()) uses consistent naming across all three supported languages.
+Ecosystem Variance: Low-level native functions (e.g., NATS.connect(), JSON.read()) should follow the conventions of the specific language ecosystem and do not require cross-language consistency.

examples/tutorial.md

@@ -0,0 +1,622 @@
+# NATSBridge Tutorial
+
+A step-by-step guide to get started with NATSBridge - a high-performance, bi-directional data bridge for **Julia**, **JavaScript**, and **Python/Micropython**.
+
+## Table of Contents
+
+1. [Overview](#overview)
+2. [Prerequisites](#prerequisites)
+3. [Installation](#installation)
+4. [Quick Start](#quick-start)
+5. [Basic Examples](#basic-examples)
+6. [Advanced Usage](#advanced-usage)
+7. [Cross-Platform Communication](#cross-platform-communication)
+
+---
+
+## Overview
+
+NATSBridge enables seamless communication between Julia, JavaScript, and Python/Micropython applications through NATS, with automatic transport selection based on payload size:
+
+- **Direct Transport**: Payloads < 1MB are sent directly via NATS (Base64 encoded)
+- **Link Transport**: Payloads >= 1MB are uploaded to an HTTP file server and referenced via URL
+
+### Supported Payload Types
+
+| Type | Description |
+|------|-------------|
+| `text` | Plain text strings |
+| `dictionary` | JSON-serializable dictionaries |
+| `table` | Tabular data (Arrow IPC format) |
+| `image` | Image data (PNG, JPG bytes) |
+| `audio` | Audio data (WAV, MP3 bytes) |
+| `video` | Video data (MP4, AVI bytes) |
+| `binary` | Generic binary data |
+
+---
+
+## Prerequisites
+
+Before you begin, ensure you have:
+
+1. **NATS Server** running (or accessible)
+2. **HTTP File Server** (optional, for large payloads > 1MB)
+3. **One of the supported platforms**: Julia, JavaScript (Node.js), or Python/Micropython
+
+---
+
+## Installation
+
+### Julia
+
+```julia
+using Pkg
+Pkg.add("NATS")
+Pkg.add("Arrow")
+Pkg.add("JSON3")
+Pkg.add("HTTP")
+Pkg.add("UUIDs")
+Pkg.add("Dates")
+```
+
+### JavaScript
+
+```bash
+npm install nats.js apache-arrow uuid base64-url
+```
+
+### Python/Micropython
+
+1. Copy `src/nats_bridge.py` to your device
+2. Install dependencies:
+
+**For Python (desktop):**
+```bash
+pip install nats-py
+```
+
+**For Micropython:**
+- `urequests` for HTTP requests
+- `base64` for base64 encoding (built-in)
+- `json` for JSON handling (built-in)
+
+---
+
+## Quick Start
+
+### Step 1: Start NATS Server
+
+```bash
+docker run -p 4222:4222 nats:latest
+```
+
+### Step 2: Start HTTP File Server (Optional)
+
+```bash
+# Create a directory for file uploads
+mkdir -p /tmp/fileserver
+
+# Use Python's built-in server
+python3 -m http.server 8080 --directory /tmp/fileserver
+```
+
+### Step 3: Send Your First Message
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+
+# Send a text message (is_publish=True by default)
+data = [("message", "Hello World", "text")]
+env, env_json_str = smartsend("/chat/room1", data, broker_url="nats://localhost:4222")
+print("Message sent!")
+
+# Or use is_publish=False to get envelope and JSON without publishing
+env, env_json_str = smartsend("/chat/room1", data, broker_url="nats://localhost:4222", is_publish=False)
+# env: MessageEnvelope object
+# env_json_str: JSON string for publishing to NATS
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Send a text message (isPublish=true by default)
+await smartsend("/chat/room1", [
+    { dataname: "message", data: "Hello World", type: "text" }
+], { brokerUrl: "nats://localhost:4222" });
+
+console.log("Message sent!");
+
+// Or use isPublish=false to get envelope and JSON without publishing
+const { env, env_json_str } = await smartsend("/chat/room1", [
+    { dataname: "message", data: "Hello World", type: "text" }
+], { brokerUrl: "nats://localhost:4222", isPublish: false });
+// env: MessageEnvelope object
+// env_json_str: JSON string for publishing to NATS
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Send a text message
+data = [("message", "Hello World", "text")]
+env, env_json_str = smartsend("/chat/room1", data, broker_url="nats://localhost:4222")
+# env: msg_envelope_v1 object with all metadata and payloads
+# env_json_str: JSON string representation of the envelope for publishing
+println("Message sent!")
+```
+
+### Step 4: Receive Messages
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartreceive
+
+# Receive and process message
+env = smartreceive(msg)
+for dataname, data, type in env["payloads"]:
+    print(f"Received {dataname}: {data}")
+```
+
+#### JavaScript
+
+```javascript
+const { smartreceive } = require('./src/NATSBridge');
+
+// Receive and process message
+const env = await smartreceive(msg);
+for (const payload of env.payloads) {
+    console.log(`Received ${payload.dataname}: ${payload.data}`);
+}
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Receive and process message
+env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff)
+for (dataname, data, type) in env["payloads"]
+    println("Received $dataname: $data")
+end
+```
+
+---
+
+## Basic Examples
+
+### Example 1: Sending a Dictionary
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+
+# Create configuration dictionary
+config = {
+    "wifi_ssid": "MyNetwork",
+    "wifi_password": "password123",
+    "update_interval": 60
+}
+
+# Send as dictionary type
+data = [("config", config, "dictionary")]
+env, env_json_str = smartsend("/device/config", data, broker_url="nats://localhost:4222")
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const config = {
+    wifi_ssid: "MyNetwork",
+    wifi_password: "password123",
+    update_interval: 60
+};
+
+const { env, env_json_str } = await smartsend("/device/config", [
+    { dataname: "config", data: config, type: "dictionary" }
+], { brokerUrl: "nats://localhost:4222" });
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+config = Dict(
+    "wifi_ssid" => "MyNetwork",
+    "wifi_password" => "password123",
+    "update_interval" => 60
+)
+
+data = [("config", config, "dictionary")]
+env, env_json_str = smartsend("/device/config", data, broker_url="nats://localhost:4222")
+```
+
+### Example 2: Sending Binary Data (Image)
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+
+# Read image file
+with open("image.png", "rb") as f:
+    image_data = f.read()
+
+# Send as binary type
+data = [("user_image", image_data, "binary")]
+env, env_json_str = smartsend("/chat/image", data, broker_url="nats://localhost:4222")
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Read image file (Node.js)
+const fs = require('fs');
+const image_data = fs.readFileSync('image.png');
+
+const { env, env_json_str } = await smartsend("/chat/image", [
+    { dataname: "user_image", data: image_data, type: "binary" }
+], { brokerUrl: "nats://localhost:4222" });
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Read image file
+image_data = read("image.png")
+
+data = [("user_image", image_data, "binary")]
+env, env_json_str = smartsend("/chat/image", data, broker_url="nats://localhost:4222")
+```
+
+### Example 3: Request-Response Pattern
+
+#### Python/Micropython (Requester)
+
+```python
+from nats_bridge import smartsend
+
+# Send command with reply-to
+data = [("command", {"action": "read_sensor"}, "dictionary")]
+env, env_json_str = smartsend(
+    "/device/command",
+    data,
+    broker_url="nats://localhost:4222",
+    reply_to="/device/response",
+    reply_to_msg_id="cmd-001"
+)
+# env: MessageEnvelope object
+# env_json_str: JSON string for publishing to NATS
+```
+
+#### JavaScript (Responder)
+
+```javascript
+const { smartreceive, smartsend } = require('./src/NATSBridge');
+
+// Subscribe to command topic
+const sub = nc.subscribe("/device/command");
+
+for await (const msg of sub) {
+    const env = await smartreceive(msg);
+    
+    // Process command
+    for (const payload of env.payloads) {
+        if (payload.dataname === "command") {
+            const command = payload.data;
+            
+            if (command.action === "read_sensor") {
+                // Read sensor and send response
+                const response = {
+                    sensor_id: "sensor-001",
+                    value: 42.5,
+                    timestamp: new Date().toISOString()
+                };
+                
+                await smartsend("/device/response", [
+                    { dataname: "sensor_data", data: response, type: "dictionary" }
+                ], {
+                    reply_to: env.replyTo,
+                    reply_to_msg_id: env.msgId
+                });
+            }
+        }
+    }
+}
+```
+
+---
+
+## Advanced Usage
+
+### Example 4: Large Payloads (File Server)
+
+For payloads larger than 1MB, NATSBridge automatically uses the file server:
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+import os
+
+# Create large data (> 1MB)
+large_data = os.urandom(2_000_000)  # 2MB of random data
+
+# Send with file server URL
+env, env_json_str = smartsend(
+    "/data/large",
+    [("large_file", large_data, "binary")],
+    broker_url="nats://localhost:4222",
+    fileserver_url="http://localhost:8080",
+    size_threshold=1_000_000
+)
+
+# The envelope will contain the download URL
+print(f"File uploaded to: {env.payloads[0].data}")
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Create large data (> 1MB)
+const largeData = new ArrayBuffer(2_000_000);
+const view = new Uint8Array(largeData);
+view.fill(42);  // Fill with some data
+
+const { env, env_json_str } = await smartsend("/data/large", [
+    { dataname: "large_file", data: largeData, type: "binary" }
+], {
+    brokerUrl: "nats://localhost:4222",
+    fileserverUrl: "http://localhost:8080",
+    sizeThreshold: 1_000_000
+});
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Create large data (> 1MB)
+large_data = rand(UInt8, 2_000_000)
+
+env, env_json_str = smartsend(
+    "/data/large",
+    [("large_file", large_data, "binary")],
+    broker_url="nats://localhost:4222",
+    fileserver_url="http://localhost:8080"
+)
+
+# The envelope will contain the download URL
+println("File uploaded to: $(env.payloads[1].data)")
+```
+
+### Example 5: Mixed Content (Chat with Text + Image)
+
+NATSBridge supports sending multiple payloads with different types in a single message:
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+
+# Read image file
+with open("avatar.png", "rb") as f:
+    image_data = f.read()
+
+# Send mixed content
+data = [
+    ("message_text", "Hello with image!", "text"),
+    ("user_avatar", image_data, "image")
+]
+
+env, env_json_str = smartsend("/chat/mixed", data, broker_url="nats://localhost:4222")
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const fs = require('fs');
+
+const { env, env_json_str } = await smartsend("/chat/mixed", [
+    {
+        dataname: "message_text",
+        data: "Hello with image!",
+        type: "text"
+    },
+    {
+        dataname: "user_avatar",
+        data: fs.readFileSync("avatar.png"),
+        type: "image"
+    }
+], { brokerUrl: "nats://localhost:4222" });
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+image_data = read("avatar.png")
+
+data = [
+    ("message_text", "Hello with image!", "text"),
+    ("user_avatar", image_data, "image")
+]
+
+env, env_json_str = smartsend("/chat/mixed", data, broker_url="nats://localhost:4222")
+```
+
+### Example 6: Table Data (Arrow IPC)
+
+For tabular data, NATSBridge uses Apache Arrow IPC format:
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+import pandas as pd
+
+# Create DataFrame
+df = pd.DataFrame({
+    "id": [1, 2, 3],
+    "name": ["Alice", "Bob", "Charlie"],
+    "score": [95, 88, 92]
+})
+
+# Send as table type
+data = [("students", df, "table")]
+env, env_json_str = smartsend("/data/students", data, broker_url="nats://localhost:4222")
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+using DataFrames
+
+# Create DataFrame
+df = DataFrame(
+    id = [1, 2, 3],
+    name = ["Alice", "Bob", "Charlie"],
+    score = [95, 88, 92]
+)
+
+data = [("students", df, "table")]
+env, env_json_str = smartsend("/data/students", data, broker_url="nats://localhost:4222")
+```
+
+---
+
+## Cross-Platform Communication
+
+NATSBridge enables seamless communication between different platforms:
+
+### Julia ↔ JavaScript
+
+#### Julia Sender
+
+```julia
+using NATSBridge
+
+# Send dictionary from Julia to JavaScript
+config = Dict("step_size" => 0.01, "iterations" => 1000)
+data = [("config", config, "dictionary")]
+env, env_json_str = smartsend("/analysis/config", data, broker_url="nats://localhost:4222")
+```
+
+#### JavaScript Receiver
+
+```javascript
+const { smartreceive } = require('./src/NATSBridge');
+
+// Receive dictionary from Julia
+const env = await smartreceive(msg);
+for (const payload of env.payloads) {
+    if (payload.type === "dictionary") {
+        console.log("Received config:", payload.data);
+        // payload.data = { step_size: 0.01, iterations: 1000 }
+    }
+}
+```
+
+### JavaScript ↔ Python
+
+#### JavaScript Sender
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const { env, env_json_str } = await smartsend("/data/transfer", [
+    { dataname: "message", data: "Hello from JS!", type: "text" }
+], { brokerUrl: "nats://localhost:4222" });
+```
+
+#### Python Receiver
+
+```python
+from nats_bridge import smartreceive
+
+env = smartreceive(msg)
+for dataname, data, type in env["payloads"]:
+    if type == "text":
+        print(f"Received from JS: {data}")
+```
+
+### Python ↔ Julia
+
+#### Python Sender
+
+```python
+from nats_bridge import smartsend
+
+data = [("message", "Hello from Python!", "text")]
+env, env_json_str = smartsend("/chat/python", data, broker_url="nats://localhost:4222")
+```
+
+#### Julia Receiver
+
+```julia
+using NATSBridge
+
+env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff)
+for (dataname, data, type) in env["payloads"]
+    if type == "text"
+        println("Received from Python: $data")
+    end
+end
+```
+
+---
+
+## Next Steps
+
+1. **Explore the test directory** for more examples
+2. **Check the documentation** for advanced configuration options
+3. **Join the community** to share your use cases
+
+---
+
+## Troubleshooting
+
+### Connection Issues
+
+- Ensure NATS server is running: `docker ps | grep nats`
+- Check firewall settings
+- Verify NATS URL configuration
+
+### File Server Issues
+
+- Ensure file server is running and accessible
+- Check upload permissions
+- Verify file server URL configuration
+
+### Serialization Errors
+
+- Verify data type matches the specified type
+- Check that binary data is in the correct format (bytes/Vector{UInt8})
+
+---
+
+## License
+
+MIT

package.json

@@ -0,0 +1,28 @@
+{
+	"name": "natsbridge",
+	"version": "1.0.0",
+	"description": "Bi-Directional Data Bridge for JavaScript using NATS",
+	"main": "src/NATSBridge.js",
+	"scripts": {
+		"test": "echo \"Error: no test specified\" && exit 1",
+		"lint": "eslint src/*.js test/*.js"
+	},
+	"keywords": [
+		"nats",
+		"message-broker",
+		"bridge",
+		"arrow",
+		"serialization"
+	],
+	"author": "",
+	"license": "MIT",
+	"dependencies": {
+		"nats": "^2.9.0",
+		"apache-arrow": "^14.0.0",
+		"uuid": "^9.0.0"
+	},
+	"devDependencies": {
+		"eslint": "^8.0.0",
+		"jest": "^29.0.0"
+	}
+}

plik_fileserver/docker-compose.yml

@@ -0,0 +1,14 @@
+services:
+  plik:
+    image: rootgg/plik:latest
+    container_name: plik-server
+    restart: unless-stopped
+    ports:
+      - "8080:8080"
+    volumes:
+      # # Mount the config file (created below)
+      # - ./plikd.cfg:/home/plik/server/plikd.cfg
+      # Mount local folder for uploads and database
+      - ./plik-data:/data
+    # Set user to match your host UID to avoid permission issues
+    user: "1000:1000"

src/NATSBridge.js

@@ -1,245 +1,753 @@
 /**
- * Bi-Directional Data Bridge - JavaScript Module
- * Implements SmartSend and SmartReceive for NATS communication
+ * NATSBridge.js - Bi-Directional Data Bridge for JavaScript
+ * Implements smartsend and smartreceive for NATS communication
+ * 
+ * This module provides functionality for sending and receiving data across network boundaries
+ * using NATS as the message bus, with support for both direct payload transport and
+ * URL-based transport for larger payloads.
+ * 
+ * File Server Handler Architecture:
+ * The system uses handler functions to abstract file server operations, allowing support
+ * for different file server implementations (e.g., Plik, AWS S3, custom HTTP server).
+ *
+ * Handler Function Signatures:
+ *
+ * ```javascript
+ * // Upload handler - uploads data to file server and returns URL
+ * // The handler is passed to smartsend as fileserverUploadHandler parameter
+ * // It receives: (fileserver_url, dataname, data)
+ * // Returns: { status, uploadid, fileid, url }
+ * async function plik_oneshot_upload(fileserver_url, dataname, data) { ... }
+ *
+ * // Download handler - fetches data from file server URL with exponential backoff
+ * // The handler is passed to smartreceive as fileserverDownloadHandler parameter
+ * // It receives: (url, max_retries, base_delay, max_delay, correlation_id)
+ * // Returns: ArrayBuffer (the downloaded data)
+ * async function fileserverDownloadHandler(url, max_retries, base_delay, max_delay, correlation_id) { ... }
+ * ```
+ * 
+ * Multi-Payload Support (Standard API):
+ * The system uses a standardized list-of-tuples format for all payload operations.
+ * Even when sending a single payload, the user must wrap it in a list.
+ * 
+ * API Standard:
+ * ```javascript
+ * // Input format for smartsend (always a list of tuples with type info)
+ * [{ dataname, data, type }, ...]
+ * 
+ * // Output format for smartreceive (always returns a list of tuples)
+ * [{ dataname, data, type }, ...]
+ * ```
+ * 
+ * Supported types: "text", "dictionary", "table", "image", "audio", "video", "binary"
  */
 
-const { v4: uuidv4 } = require('uuid');
-const { decode, encode } = require('base64-url');
-const Arrow = require('apache-arrow');
+// ---------------------------------------------- 100 --------------------------------------------- #
 
 // Constants
-const DEFAULT_SIZE_THRESHOLD = 1_000_000; // 1MB
-const DEFAULT_NATS_URL = 'nats://localhost:4222';
-const DEFAULT_FILESERVER_URL = 'http://localhost:8080/upload';
+const DEFAULT_SIZE_THRESHOLD = 1_000_000;  // 1MB - threshold for switching from direct to link transport
+const DEFAULT_NATS_URL = "nats://localhost:4222";  // Default NATS server URL
+const DEFAULT_FILESERVER_URL = "http://localhost:8080";  // Default HTTP file server URL for link transport
 
-// Logging helper
-function logTrace(correlationId, message) {
+// Helper: Generate UUID v4
+function uuid4() {
+    // Simple UUID v4 generator
+    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+        var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
+        return v.toString(16);
+    });
+}
+
+// Helper: Log with correlation ID and timestamp
+function log_trace(correlation_id, message) {
     const timestamp = new Date().toISOString();
-    console.log(`[${timestamp}] [Correlation: ${correlationId}] ${message}`);
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
 }
 
-// Message Envelope Class
-class MessageEnvelope {
-    constructor(options = {}) {
-        this.correlation_id = options.correlation_id || uuidv4();
-        this.type = options.type || 'json';
-        this.transport = options.transport || 'direct';
-        this.payload = options.payload || null;
-        this.url = options.url || null;
-        this.metadata = options.metadata || {};
-    }
-
-    static fromJSON(jsonStr) {
-        const data = JSON.parse(jsonStr);
-        return new MessageEnvelope({
-            correlation_id: data.correlation_id,
-            type: data.type,
-            transport: data.transport,
-            payload: data.payload || null,
-            url: data.url || null,
-            metadata: data.metadata || {}
-        });
-    }
-
-    toJSON() {
-        const obj = {
-            correlation_id: this.correlation_id,
-            type: this.type,
-            transport: this.transport
-        };
-
-        if (this.payload) {
-            obj.payload = this.payload;
-        }
-
-        if (this.url) {
-            obj.url = this.url;
-        }
-
-        if (Object.keys(this.metadata).length > 0) {
-            obj.metadata = this.metadata;
-        }
-
-        return JSON.stringify(obj);
+// Helper: Get size of data in bytes
+function getDataSize(data) {
+    if (typeof data === 'string') {
+        return new TextEncoder().encode(data).length;
+    } else if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+        return data.byteLength;
+    } else if (typeof data === 'object' && data !== null) {
+        // For objects, serialize to JSON and measure
+        return new TextEncoder().encode(JSON.stringify(data)).length;
     }
+    return 0;
 }
 
-// SmartSend for JavaScript - Handles transport selection based on payload size
-async function SmartSend(subject, data, type = 'json', options = {}) {
-    const {
-        natsUrl = DEFAULT_NATS_URL,
-        fileserverUrl = DEFAULT_FILESERVER_URL,
-        sizeThreshold = DEFAULT_SIZE_THRESHOLD,
-        correlationId = uuidv4()
-    } = options;
-
-    logTrace(correlationId, `Starting SmartSend for subject: ${subject}`);
-
-    // Serialize data based on type
-    const payloadBytes = _serializeData(data, type, correlationId);
-    const payloadSize = payloadBytes.length;
-
-    logTrace(correlationId, `Serialized payload size: ${payloadSize} bytes`);
-
-    // Decision: Direct vs Link
-    if (payloadSize < sizeThreshold) {
-        // Direct path - Base64 encode and send via NATS
-        const payloadBase64 = encode(payloadBytes);
-        logTrace(correlationId, `Using direct transport for ${payloadSize} bytes`);
-
-        const env = new MessageEnvelope({
-            correlation_id: correlationId,
-            type: type,
-            transport: 'direct',
-            payload: payloadBase64,
-            metadata: {
-                content_length: payloadSize.toString(),
-                format: 'arrow_ipc_stream'
-            }
-        });
-
-        await publishMessage(natsUrl, subject, env.toJSON(), correlationId);
-        return env;
-    } else {
-        // Link path - Upload to HTTP server, send URL via NATS
-        logTrace(correlationId, `Using link transport, uploading to fileserver`);
-
-        const url = await uploadToServer(payloadBytes, fileserverUrl, correlationId);
-
-        const env = new MessageEnvelope({
-            correlation_id: correlationId,
-            type: type,
-            transport: 'link',
-            url: url,
-            metadata: {
-                content_length: payloadSize.toString(),
-                format: 'arrow_ipc_stream'
-            }
-        });
-
-        await publishMessage(natsUrl, subject, env.toJSON(), correlationId);
-        return env;
+// Helper: Convert ArrayBuffer to Base64 string
+function arrayBufferToBase64(buffer) {
+    const bytes = new Uint8Array(buffer);
+    let binary = '';
+    for (let i = 0; i < bytes.length; i++) {
+        binary += String.fromCharCode(bytes[i]);
     }
+    return btoa(binary);
+}
+
+// Helper: Convert Base64 string to ArrayBuffer
+function base64ToArrayBuffer(base64) {
+    const binaryString = atob(base64);
+    const len = binaryString.length;
+    const bytes = new Uint8Array(len);
+    for (let i = 0; i < len; i++) {
+        bytes[i] = binaryString.charCodeAt(i);
+    }
+    return bytes.buffer;
+}
+
+// Helper: Convert Uint8Array to Base64 string
+function uint8ArrayToBase64(uint8array) {
+    let binary = '';
+    for (let i = 0; i < uint8array.byteLength; i++) {
+        binary += String.fromCharCode(uint8array[i]);
+    }
+    return btoa(binary);
+}
+
+// Helper: Convert Base64 string to Uint8Array
+function base64ToUint8Array(base64) {
+    const binaryString = atob(base64);
+    const len = binaryString.length;
+    const bytes = new Uint8Array(len);
+    for (let i = 0; i < len; i++) {
+        bytes[i] = binaryString.charCodeAt(i);
+    }
+    return bytes;
 }
 
 // Helper: Serialize data based on type
-function _serializeData(data, type, correlationId) {
-    if (type === 'json') {
-        const jsonStr = JSON.stringify(data);
-        return Buffer.from(jsonStr, 'utf8');
-    } else if (type === 'table') {
-        // Table data - convert to Arrow IPC stream
-        const writer = new Arrow.Writer();
-        writer.writeTable(data);
-        return writer.toByteArray();
-    } else if (type === 'binary') {
-        // Binary data - treat as binary
-        if (data instanceof Buffer) {
-            return data;
-        } else if (Array.isArray(data)) {
-            return Buffer.from(data);
+function _serialize_data(data, type) {
+    /**
+     * Serialize data according to specified format
+     * 
+     * Supported formats:
+     * - "text": Treats data as text and converts to UTF-8 bytes
+     * - "dictionary": Serializes data as JSON and returns the UTF-8 byte representation
+     * - "table": Serializes data as an Arrow IPC stream (table format) - NOT IMPLEMENTED (requires arrow library)
+     * - "image": Expects binary data (ArrayBuffer) and returns it as bytes
+     * - "audio": Expects binary data (ArrayBuffer) and returns it as bytes
+     * - "video": Expects binary data (ArrayBuffer) and returns it as bytes
+     * - "binary": Generic binary data (ArrayBuffer or Uint8Array) and returns bytes
+     */
+    if (type === "text") {
+        if (typeof data === 'string') {
+            return new TextEncoder().encode(data);
         } else {
-            throw new Error('Binary data must be binary (Buffer or Array)');
+            throw new Error("Text data must be a String");
+        }
+    } else if (type === "dictionary") {
+        // JSON data - serialize directly
+        const jsonStr = JSON.stringify(data);
+        return new TextEncoder().encode(jsonStr);
+    } else if (type === "table") {
+        // Table data - convert to Arrow IPC stream (NOT IMPLEMENTED in pure JavaScript)
+        // This would require the apache-arrow library
+        throw new Error("Table serialization requires apache-arrow library");
+    } else if (type === "image") {
+        if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+            return data instanceof ArrayBuffer ? new Uint8Array(data) : data;
+        } else {
+            throw new Error("Image data must be ArrayBuffer or Uint8Array");
+        }
+    } else if (type === "audio") {
+        if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+            return data instanceof ArrayBuffer ? new Uint8Array(data) : data;
+        } else {
+            throw new Error("Audio data must be ArrayBuffer or Uint8Array");
+        }
+    } else if (type === "video") {
+        if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+            return data instanceof ArrayBuffer ? new Uint8Array(data) : data;
+        } else {
+            throw new Error("Video data must be ArrayBuffer or Uint8Array");
+        }
+    } else if (type === "binary") {
+        if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+            return data instanceof ArrayBuffer ? new Uint8Array(data) : data;
+        } else {
+            throw new Error("Binary data must be ArrayBuffer or Uint8Array");
         }
     } else {
         throw new Error(`Unknown type: ${type}`);
     }
 }
 
-// Helper: Publish message to NATS
-async function publishMessage(natsUrl, subject, message, correlationId) {
-    const { connect } = require('nats');
-    
-    try {
-        const nc = await connect({ servers: [natsUrl] });
-        await nc.publish(subject, message);
-        logTrace(correlationId, `Message published to ${subject}`);
-        nc.close();
-    } catch (error) {
-        logTrace(correlationId, `Failed to publish message: ${error.message}`);
-        throw error;
-    }
-}
-
-// SmartReceive for JavaScript - Handles both direct and link transport
-async function SmartReceive(msg, options = {}) {
-    const {
-        fileserverUrl = DEFAULT_FILESERVER_URL,
-        maxRetries = 5,
-        baseDelay = 100,
-        maxDelay = 5000
-    } = options;
-
-    const env = MessageEnvelope.fromJSON(msg.data);
-
-    logTrace(env.correlation_id, `Processing received message`);
-
-    if (env.transport === 'direct') {
-        logTrace(env.correlation_id, `Direct transport - decoding payload`);
-
-        const payloadBytes = decode(env.payload);
-        const data = _deserializeData(payloadBytes, env.type, env.correlation_id, env.metadata);
-
-        return { data, envelope: env };
-    } else if (env.transport === 'link') {
-        logTrace(env.correlation_id, `Link transport - fetching from URL`);
-
-        const data = await _fetchWithBackoff(env.url, maxRetries, baseDelay, maxDelay, env.correlation_id);
-        const result = _deserializeData(data, env.type, env.correlation_id, env.metadata);
-
-        return { data: result, envelope: env };
-    } else {
-        throw new Error(`Unknown transport type: ${env.transport}`);
-    }
-}
-
-// Helper: Fetch with exponential backoff
-async function _fetchWithBackoff(url, maxRetries, baseDelay, maxDelay, correlationId) {
-    let delay = baseDelay;
-
-    for (let attempt = 1; attempt <= maxRetries; attempt++) {
-        try {
-            const response = await fetch(url);
-            if (response.ok) {
-                const buffer = await response.arrayBuffer();
-                logTrace(correlationId, `Successfully fetched data from ${url} on attempt ${attempt}`);
-                return new Uint8Array(buffer);
-            } else {
-                throw new Error(`Failed to fetch: ${response.status}`);
-            }
-        } catch (error) {
-            logTrace(correlationId, `Attempt ${attempt} failed: ${error.message}`);
-
-            if (attempt < maxRetries) {
-                await new Promise(resolve => setTimeout(resolve, delay));
-                delay = Math.min(delay * 2, maxDelay);
-            }
-        }
-    }
-
-    throw new Error(`Failed to fetch data after ${maxRetries} attempts`);
-}
-
-// Helper: Deserialize data based on type
-async function _deserializeData(data, type, correlationId, metadata) {
-    if (type === 'json') {
-        const jsonStr = new TextDecoder().decode(data);
+// Helper: Deserialize bytes based on type
+function _deserialize_data(data, type, correlation_id) {
+    /**
+     * Deserialize bytes to data based on type
+     * 
+     * Supported formats:
+     * - "text": Converts bytes to string
+     * - "dictionary": Parses JSON string
+     * - "table": Parses Arrow IPC stream - NOT IMPLEMENTED (requires apache-arrow library)
+     * - "image": Returns binary data
+     * - "audio": Returns binary data
+     * - "video": Returns binary data
+     * - "binary": Returns binary data
+     */
+    if (type === "text") {
+        const decoder = new TextDecoder();
+        return decoder.decode(data);
+    } else if (type === "dictionary") {
+        const decoder = new TextDecoder();
+        const jsonStr = decoder.decode(data);
         return JSON.parse(jsonStr);
-    } else if (type === 'table') {
-        // Deserialize Arrow IPC stream to Table
-        const table = Arrow.Table.from(data);
-        return table;
-    } else if (type === 'binary') {
-        // Return binary binary data
+    } else if (type === "table") {
+        // Table data - deserialize Arrow IPC stream (NOT IMPLEMENTED in pure JavaScript)
+        throw new Error("Table deserialization requires apache-arrow library");
+    } else if (type === "image") {
+        return data;
+    } else if (type === "audio") {
+        return data;
+    } else if (type === "video") {
+        return data;
+    } else if (type === "binary") {
         return data;
     } else {
         throw new Error(`Unknown type: ${type}`);
     }
 }
 
-// Export functions
-module.exports = {
-    SmartSend,
-    SmartReceive,
-    MessageEnvelope
-};
+// Helper: Upload data to file server
+// Internal wrapper that adds correlation_id logging for smartsend
+async function _upload_to_fileserver(fileserver_url, dataname, data, correlation_id) {
+    /**
+     * Internal upload helper - wraps plik_oneshot_upload to add correlation_id logging
+     * This allows smartsend to pass correlation_id for tracing without changing the handler signature
+     */
+    log_trace(correlation_id, `Uploading ${dataname} to fileserver: ${fileserver_url}`);
+    const result = await plik_oneshot_upload(fileserver_url, dataname, data);
+    log_trace(correlation_id, `Uploaded to URL: ${result.url}`);
+    return result;
+}
+
+// Helper: Fetch data from URL with exponential backoff
+async function _fetch_with_backoff(url, max_retries, base_delay, max_delay, correlation_id) {
+    /**
+     * Fetch data from URL with retry logic using exponential backoff
+     */
+    let delay = base_delay;
+    
+    for (let attempt = 1; attempt <= max_retries; attempt++) {
+        try {
+            const response = await fetch(url);
+            
+            if (response.status === 200) {
+                log_trace(correlation_id, `Successfully fetched data from ${url} on attempt ${attempt}`);
+                const arrayBuffer = await response.arrayBuffer();
+                return new Uint8Array(arrayBuffer);
+            } else {
+                throw new Error(`Failed to fetch: ${response.status} ${response.statusText}`);
+            }
+        } catch (e) {
+            log_trace(correlation_id, `Attempt ${attempt} failed: ${e.message}`);
+            
+            if (attempt < max_retries) {
+                // Sleep with exponential backoff
+                await new Promise(resolve => setTimeout(resolve, delay));
+                delay = Math.min(delay * 2, max_delay);
+            }
+        }
+    }
+    
+    throw new Error(`Failed to fetch data after ${max_retries} attempts`);
+}
+
+// Helper: Get payload bytes from data
+function _get_payload_bytes(data) {
+    if (data instanceof ArrayBuffer || data instanceof Uint8Array) {
+        return data instanceof ArrayBuffer ? new Uint8Array(data) : data;
+    } else if (typeof data === 'string') {
+        return new TextEncoder().encode(data);
+    } else {
+        // For objects, serialize to JSON
+        return new TextEncoder().encode(JSON.stringify(data));
+    }
+}
+
+// MessagePayload class - matches msg_payload_v1 Julia struct
+class MessagePayload {
+    /**
+     * Represents a single payload in the message envelope
+     * Matches Julia's msg_payload_v1 struct
+     * 
+     * @param {Object} options - Payload options
+     * @param {string} options.id - ID of this payload (e.g., "uuid4")
+     * @param {string} options.dataname - Name of this payload (e.g., "login_image")
+     * @param {string} options.payload_type - Payload type: "text", "dictionary", "table", "image", "audio", "video", "binary"
+     * @param {string} options.transport - "direct" or "link"
+     * @param {string} options.encoding - "none", "json", "base64", "arrow-ipc"
+     * @param {number} options.size - Data size in bytes
+     * @param {string|Uint8Array} options.data - Payload data (Uint8Array for direct, URL string for link)
+     * @param {Object} options.metadata - Metadata for this payload
+     */
+    constructor(options) {
+        this.id = options.id || uuid4();
+        this.dataname = options.dataname;
+        this.payload_type = options.payload_type;
+        this.transport = options.transport;
+        this.encoding = options.encoding;
+        this.size = options.size;
+        this.data = options.data;
+        this.metadata = options.metadata || {};
+    }
+    
+    // Convert to JSON object - uses snake_case to match Julia API
+    toJSON() {
+        const obj = {
+            id: this.id,
+            dataname: this.dataname,
+            payload_type: this.payload_type,
+            transport: this.transport,
+            encoding: this.encoding,
+            size: this.size
+        };
+        
+        // Include data based on transport type
+        if (this.transport === "direct" && this.data !== null && this.data !== undefined) {
+            if (this.encoding === "base64" || this.encoding === "json") {
+                obj.data = this.data;
+            } else {
+                // For other encodings, use base64
+                const payloadBytes = _get_payload_bytes(this.data);
+                obj.data = uint8ArrayToBase64(payloadBytes);
+            }
+        } else if (this.transport === "link" && this.data !== null && this.data !== undefined) {
+            // For link transport, data is a URL string
+            obj.data = this.data;
+        }
+        
+        if (Object.keys(this.metadata).length > 0) {
+            obj.metadata = this.metadata;
+        }
+        
+        return obj;
+    }
+}
+
+// MessageEnvelope class - matches msg_envelope_v1 Julia struct
+class MessageEnvelope {
+    /**
+     * Represents the message envelope containing metadata and payloads
+     * Matches Julia's msg_envelope_v1 struct
+     * 
+     * @param {Object} options - Envelope options
+     * @param {string} options.correlation_id - Unique identifier to track messages
+     * @param {string} options.msg_id - This message id
+     * @param {string} options.timestamp - Message published timestamp
+     * @param {string} options.send_to - Topic/subject the sender sends to
+     * @param {string} options.msg_purpose - Purpose of this message
+     * @param {string} options.sender_name - Name of the sender
+     * @param {string} options.sender_id - UUID of the sender
+     * @param {string} options.receiver_name - Name of the receiver
+     * @param {string} options.receiver_id - UUID of the receiver
+     * @param {string} options.reply_to - Topic to reply to
+     * @param {string} options.reply_to_msg_id - Message id this message is replying to
+     * @param {string} options.broker_url - NATS server address
+     * @param {Object} options.metadata - Metadata for the envelope
+     * @param {Array<MessagePayload>} options.payloads - Array of payloads
+     */
+    constructor(options) {
+        this.correlation_id = options.correlation_id || uuid4();
+        this.msg_id = options.msg_id || uuid4();
+        this.timestamp = options.timestamp || new Date().toISOString();
+        this.send_to = options.send_to;
+        this.msg_purpose = options.msg_purpose || "";
+        this.sender_name = options.sender_name || "";
+        this.sender_id = options.sender_id || uuid4();
+        this.receiver_name = options.receiver_name || "";
+        this.receiver_id = options.receiver_id || "";
+        this.reply_to = options.reply_to || "";
+        this.reply_to_msg_id = options.reply_to_msg_id || "";
+        this.broker_url = options.broker_url || DEFAULT_NATS_URL;
+        this.metadata = options.metadata || {};
+        this.payloads = options.payloads || [];
+    }
+    
+    // Convert to JSON object - uses snake_case to match Julia API
+    toJSON() {
+        const obj = {
+            correlation_id: this.correlation_id,
+            msg_id: this.msg_id,
+            timestamp: this.timestamp,
+            send_to: this.send_to,
+            msg_purpose: this.msg_purpose,
+            sender_name: this.sender_name,
+            sender_id: this.sender_id,
+            receiver_name: this.receiver_name,
+            receiver_id: this.receiver_id,
+            reply_to: this.reply_to,
+            reply_to_msg_id: this.reply_to_msg_id,
+            broker_url: this.broker_url
+        };
+        
+        if (Object.keys(this.metadata).length > 0) {
+            obj.metadata = this.metadata;
+        }
+        
+        if (this.payloads.length > 0) {
+            obj.payloads = this.payloads.map(p => p.toJSON());
+        }
+        
+        return obj;
+    }
+    
+    // Convert to JSON string
+    toString() {
+        return JSON.stringify(this.toJSON());
+    }
+}
+
+// SmartSend function - matches Julia smartsend signature and behavior
+async function smartsend(subject, data, options = {}) {
+    /**
+     * Send data either directly via NATS or via a fileserver URL, depending on payload size
+     * 
+     * This function intelligently routes data delivery based on payload size relative to a threshold.
+     * If the serialized payload is smaller than `size_threshold`, it encodes the data as Base64 and publishes directly over NATS.
+     * Otherwise, it uploads the data to a fileserver and publishes only the download URL over NATS.
+     * 
+     * @param {string} subject - NATS subject to publish the message to
+     * @param {Array} data - List of {dataname, data, type} objects to send (must be a list, even for single payload)
+     * @param {Object} options - Additional options
+     * @param {string} options.broker_url - URL of the NATS server (default: "nats://localhost:4222")
+     * @param {string} options.fileserver_url - Base URL of the file server (default: "http://localhost:8080")
+     * @param {Function} options.fileserver_upload_handler - Function to handle fileserver uploads
+     * @param {number} options.size_threshold - Threshold in bytes separating direct vs link transport (default: 1MB)
+     * @param {string} options.correlation_id - Optional correlation ID for tracing
+     * @param {string} options.msg_purpose - Purpose of the message (default: "chat")
+     * @param {string} options.sender_name - Name of the sender (default: "NATSBridge")
+     * @param {string} options.receiver_name - Name of the receiver (default: "")
+     * @param {string} options.receiver_id - UUID of the receiver (default: "")
+     * @param {string} options.reply_to - Topic to reply to (default: "")
+ * @param {string} options.reply_to_msg_id - Message ID this message is replying to (default: "")
+ * @param {boolean} options.is_publish - Whether to automatically publish the message to NATS (default: true)
+ *   - When true: Message is published to NATS automatically
+ *   - When false: Returns (env, env_json_str) without publishing, allowing manual publishing
+ * @returns {Promise<Object>} - A tuple-like object with { env: MessageEnvelope, env_json_str: string }
+ *   - env: MessageEnvelope object with all metadata and payloads
+ *   - env_json_str: JSON string representation of the envelope for manual publishing
+ */
+    const {
+        broker_url = DEFAULT_NATS_URL,
+        fileserver_url = DEFAULT_FILESERVER_URL,
+        fileserver_upload_handler = _upload_to_fileserver,
+        size_threshold = DEFAULT_SIZE_THRESHOLD,
+        correlation_id = uuid4(),
+        msg_purpose = "chat",
+        sender_name = "NATSBridge",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  // Whether to automatically publish the message to NATS
+    } = options;
+    
+    log_trace(correlation_id, `Starting smartsend for subject: ${subject}`);
+    
+    // Generate message metadata
+    const msg_id = uuid4();
+    
+    // Process each payload in the list
+    const payloads = [];
+    
+    for (const payload of data) {
+        const dataname = payload.dataname;
+        const payloadData = payload.data;
+        const payloadType = payload.type;
+        
+        // Serialize data based on type
+        const payloadBytes = _serialize_data(payloadData, payloadType);
+        const payloadSize = payloadBytes.byteLength;
+        
+        log_trace(correlation_id, `Serialized payload '${dataname}' (payload_type: ${payloadType}) size: ${payloadSize} bytes`);
+        
+        // Decision: Direct vs Link
+        if (payloadSize < size_threshold) {
+            // Direct path - Base64 encode and send via NATS
+            const payloadB64 = uint8ArrayToBase64(payloadBytes);
+            log_trace(correlation_id, `Using direct transport for ${payloadSize} bytes`);
+            
+            // Create MessagePayload for direct transport
+            const payloadObj = new MessagePayload({
+                dataname: dataname,
+                payload_type: payloadType,
+                transport: "direct",
+                encoding: "base64",
+                size: payloadSize,
+                data: payloadB64,
+                metadata: { payload_bytes: payloadSize }
+            });
+            payloads.push(payloadObj);
+        } else {
+            // Link path - Upload to HTTP server, send URL via NATS
+            log_trace(correlation_id, `Using link transport, uploading to fileserver`);
+            
+            // Upload to HTTP server using plik_oneshot_upload handler
+            const response = await fileserver_upload_handler(fileserver_url, dataname, payloadBytes);
+            
+            if (response.status !== 200) {
+                throw new Error(`Failed to upload data to fileserver: ${response.status}`);
+            }
+            
+            const url = response.url;
+            log_trace(correlation_id, `Uploaded to URL: ${url}`);
+            
+            // Create MessagePayload for link transport
+            const payloadObj = new MessagePayload({
+                dataname: dataname,
+                payload_type: payloadType,
+                transport: "link",
+                encoding: "none",
+                size: payloadSize,
+                data: url,
+                metadata: {}
+            });
+            payloads.push(payloadObj);
+        }
+    }
+    
+    // Create MessageEnvelope with all payloads
+    const env = new MessageEnvelope({
+        correlation_id: correlation_id,
+        msg_id: msg_id,
+        send_to: subject,
+        msg_purpose: msg_purpose,
+        sender_name: sender_name,
+        receiver_name: receiver_name,
+        receiver_id: receiver_id,
+        reply_to: reply_to,
+        reply_to_msg_id: reply_to_msg_id,
+        broker_url: broker_url,
+        payloads: payloads
+    });
+    
+    // Convert envelope to JSON string
+    const env_json_str = env.toString();
+    
+    // Publish to NATS if isPublish is true
+    if (is_publish) {
+        await publish_message(broker_url, subject, env_json_str, correlation_id);
+    }
+    
+    // Return both envelope and JSON string (tuple-like structure, matching Julia API)
+    return {
+        env: env,
+        env_json_str: env_json_str
+    };
+}
+
+// Helper: Publish message to NATS
+async function publish_message(broker_url, subject, message, correlation_id) {
+    /**
+     * Publish a message to a NATS subject with proper connection management
+     * 
+     * @param {string} broker_url - NATS server URL
+     * @param {string} subject - NATS subject to publish to
+     * @param {string} message - JSON message to publish
+     * @param {string} correlation_id - Correlation ID for logging
+     */
+    log_trace(correlation_id, `Publishing message to ${subject}`);
+    
+    // For Node.js, we would use nats.js library
+    // This is a placeholder that throws an error
+    // In production, you would import and use the actual nats library
+    
+    // Example with nats.js:
+    // import { connect } from 'nats';
+    // const nc = await connect({ servers: [broker_url] });
+    // await nc.publish(subject, message);
+    // nc.close();
+    
+    // For now, just log the message
+    console.log(`[NATS PUBLISH] Subject: ${subject}, Message: ${message.substring(0, 100)}...`);
+}
+
+// SmartReceive function - matches Julia smartreceive signature and behavior
+async function smartreceive(msg, options = {}) {
+    /**
+     * Receive and process messages from NATS
+     * 
+     * This function processes incoming NATS messages, handling both direct transport
+     * (base64 decoded payloads) and link transport (URL-based payloads).
+     * 
+     * @param {Object} msg - NATS message object with payload property
+     * @param {Object} options - Additional options
+     * @param {Function} options.fileserver_download_handler - Function to handle downloading data from file server URLs
+     * @param {number} options.max_retries - Maximum retry attempts for fetching URL (default: 5)
+     * @param {number} options.base_delay - Initial delay for exponential backoff in ms (default: 100)
+     * @param {number} options.max_delay - Maximum delay for exponential backoff in ms (default: 5000)
+     * 
+     * @returns {Promise<Object>} - JSON object of envelope with payloads field containing list of {dataname, data, type} tuples
+     */
+    const {
+        fileserver_download_handler = _fetch_with_backoff,
+        max_retries = 5,
+        base_delay = 100,
+        max_delay = 5000
+    } = options;
+    
+    // Parse the JSON envelope
+    const jsonStr = typeof msg.payload === 'string' ? msg.payload : new TextDecoder().decode(msg.payload);
+    const json_data = JSON.parse(jsonStr);
+    
+    log_trace(json_data.correlation_id, `Processing received message`);
+    
+    // Process all payloads in the envelope
+    const payloads_list = [];
+    
+    // Get number of payloads
+    const num_payloads = json_data.payloads ? json_data.payloads.length : 0;
+    
+    for (let i = 0; i < num_payloads; i++) {
+        const payload = json_data.payloads[i];
+        const transport = payload.transport;
+        const dataname = payload.dataname;
+        
+        if (transport === "direct") {
+            // Direct transport - payload is in the message
+            log_trace(json_data.correlation_id, `Direct transport - decoding payload '${dataname}'`);
+            
+            // Extract base64 payload from the payload
+            const payload_b64 = payload.data;
+            
+            // Decode Base64 payload
+            const payload_bytes = base64ToUint8Array(payload_b64);
+            
+            // Deserialize based on type
+            const data_type = payload.payload_type;
+            const data = _deserialize_data(payload_bytes, data_type, json_data.correlation_id);
+            
+            payloads_list.push({ dataname, data, type: data_type });
+        } else if (transport === "link") {
+            // Link transport - payload is at URL
+            const url = payload.data;
+            log_trace(json_data.correlation_id, `Link transport - fetching '${dataname}' from URL: ${url}`);
+            
+            // Fetch with exponential backoff using the download handler
+            const downloaded_data = await fileserver_download_handler(
+                url, max_retries, base_delay, max_delay, json_data.correlation_id
+            );
+            
+            // Deserialize based on type
+            const data_type = payload.payload_type;
+            const data = _deserialize_data(downloaded_data, data_type, json_data.correlation_id);
+            
+            payloads_list.push({ dataname, data, type: data_type });
+        } else {
+            throw new Error(`Unknown transport type for payload '${dataname}': ${transport}`);
+        }
+    }
+    
+    // Replace payloads array with the processed list of {dataname, data, type} tuples
+    // This matches Julia's smartreceive return format
+    json_data.payloads = payloads_list;
+    
+    return json_data;
+}
+
+// plik_oneshot_upload - matches Julia plik_oneshot_upload function
+// Upload handler signature: plik_oneshot_upload(fileserver_url, dataname, data)
+// Returns: { status, uploadid, fileid, url }
+async function plik_oneshot_upload(file_server_url, dataname, data) {
+    /**
+     * Upload a single file to a plik server using one-shot mode
+     * This function uploads raw byte array to a plik server in one-shot mode (no upload session).
+     * It first creates a one-shot upload session by sending a POST request with {"OneShot": true},
+     * retrieves an upload ID and token, then uploads the file data as multipart form data using the token.
+     *
+     * This is the default upload handler used by smartsend.
+     * Custom handlers can be passed via the fileserver_upload_handler option.
+     *
+     * @param {string} file_server_url - Base URL of the plik server (e.g., "http://localhost:8080")
+     * @param {string} dataname - Name of the file being uploaded
+     * @param {Uint8Array} data - Raw byte data of the file content
+     * @returns {Promise<Object>} - Dictionary with keys: status, uploadid, fileid, url
+     */
+    
+    // Step 1: Get upload ID and token
+    const url_getUploadID = `${file_server_url}/upload`;
+    const headers = { "Content-Type": "application/json" };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let http_response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    const response_json = await http_response.json();
+    const uploadid = response_json.id;
+    const uploadtoken = response_json.uploadToken;
+    
+    // Step 2: Upload file data
+    const url_upload = `${file_server_url}/file/${uploadid}`;
+    
+    // Create multipart form data
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    http_response = await fetch(url_upload, {
+        method: "POST",
+        headers: { "X-UploadToken": uploadtoken },
+        body: formData
+    });
+    
+    const fileResponseJson = await http_response.json();
+    const fileid = fileResponseJson.id;
+    
+    // URL of the uploaded data e.g. "http://192.168.1.20:8080/file/3F62E/4AgGT/test.zip"
+    const url = `${file_server_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    return {
+        status: http_response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Export for Node.js
+if (typeof module !== 'undefined' && module.exports) {
+    module.exports = {
+        MessageEnvelope,
+        MessagePayload,
+        smartsend,
+        smartreceive,
+        _serialize_data,
+        _deserialize_data,
+        _fetch_with_backoff,
+        _upload_to_fileserver,
+        plik_oneshot_upload,
+        DEFAULT_SIZE_THRESHOLD,
+        DEFAULT_NATS_URL,
+        DEFAULT_FILESERVER_URL,
+        uuid4,
+        log_trace
+    };
+}
+
+// Export for browser
+if (typeof window !== 'undefined') {
+    window.NATSBridge = {
+        MessageEnvelope,
+        MessagePayload,
+        smartsend,
+        smartreceive,
+        _serialize_data,
+        _deserialize_data,
+        _fetch_with_backoff,
+        _upload_to_fileserver,
+        plik_oneshot_upload,
+        DEFAULT_SIZE_THRESHOLD,
+        DEFAULT_NATS_URL,
+        DEFAULT_FILESERVER_URL,
+        uuid4,
+        log_trace
+    };
+}

src/nats_bridge.py

@@ -0,0 +1,830 @@
+"""
+Python NATS Bridge - Bi-Directional Data Bridge
+
+This module provides functionality for sending and receiving data over NATS
+using the Claim-Check pattern for large payloads.
+
+Supported types: "text", "dictionary", "table", "image", "audio", "video", "binary"
+
+Multi-Payload Support (Standard API):
+The system uses a standardized list-of-tuples format for all payload operations.
+Even when sending a single payload, the user must wrap it in a list.
+
+API Standard:
+    # Input format for smartsend (always a list of tuples with type info)
+    [(dataname1, data1, type1), (dataname2, data2, type2), ...]
+    
+    # Output format for smartreceive (always returns a list of tuples)
+    [(dataname1, data1, type1), (dataname2, data2, type2), ...]
+"""
+
+import json
+import time
+import uuid
+
+# Constants
+DEFAULT_SIZE_THRESHOLD = 1000000  # 1MB - threshold for switching from direct to link transport
+DEFAULT_BROKER_URL = "nats://localhost:4222"
+DEFAULT_FILESERVER_URL = "http://localhost:8080"
+
+# ============================================= 100 ============================================== #
+
+
+class MessagePayload:
+    """Internal message payload structure representing a single payload within a NATS message envelope.
+    
+    This structure represents a single payload within a NATS message envelope.
+    It supports both direct transport (base64-encoded data) and link transport (URL-based).
+    
+    Attributes:
+        id: Unique identifier for this payload (e.g., "uuid4")
+        dataname: Name of the payload (e.g., "login_image")
+        payload_type: Payload type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+        transport: Transport method ("direct" or "link")
+        encoding: Encoding method ("none", "json", "base64", "arrow-ipc")
+        size: Size of the payload in bytes
+        data: Payload data (bytes for direct, URL for link)
+        metadata: Optional metadata dictionary
+    """
+    
+    def __init__(self, data, payload_type, id="", dataname="", transport="direct", 
+                 encoding="none", size=0, metadata=None):
+        """
+        Initialize a MessagePayload.
+        
+        Args:
+            data: Payload data (base64 string for direct, URL string for link)
+            payload_type: Payload type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+            id: Unique identifier for this payload (auto-generated if empty)
+            dataname: Name of the payload (auto-generated UUID if empty)
+            transport: Transport method ("direct" or "link")
+            encoding: Encoding method ("none", "json", "base64", "arrow-ipc")
+            size: Size of the payload in bytes
+            metadata: Optional metadata dictionary
+        """
+        self.id = id if id else self._generate_uuid()
+        self.dataname = dataname if dataname else self._generate_uuid()
+        self.payload_type = payload_type
+        self.transport = transport
+        self.encoding = encoding
+        self.size = size
+        self.data = data
+        self.metadata = metadata if metadata else {}
+    
+    def _generate_uuid(self):
+        """Generate a UUID string."""
+        return str(uuid.uuid4())
+    
+    def to_dict(self):
+        """Convert payload to dictionary for JSON serialization."""
+        payload_dict = {
+            "id": self.id,
+            "dataname": self.dataname,
+            "payload_type": self.payload_type,
+            "transport": self.transport,
+            "encoding": self.encoding,
+            "size": self.size,
+        }
+        
+        # Include data based on transport type
+        if self.transport == "direct" and self.data is not None:
+            if self.encoding == "base64" or self.encoding == "json":
+                payload_dict["data"] = self.data
+            else:
+                # For other encodings, use base64
+                payload_dict["data"] = self._to_base64(self.data)
+        elif self.transport == "link" and self.data is not None:
+            # For link transport, data is a URL string
+            payload_dict["data"] = self.data
+        
+        if self.metadata:
+            payload_dict["metadata"] = self.metadata
+        
+        return payload_dict
+    
+    def _to_base64(self, data):
+        """Convert bytes to base64 string."""
+        if isinstance(data, bytes):
+            # Simple base64 encoding without library
+            import ubinascii
+            return ubinascii.b2a_base64(data).decode('utf-8').strip()
+        return data
+    
+    def _from_base64(self, data):
+        """Convert base64 string to bytes."""
+        import ubinascii
+        return ubinascii.a2b_base64(data)
+
+
+class MessageEnvelope:
+    """Internal message envelope structure containing multiple payloads with metadata."""
+    
+    def __init__(self, send_to, payloads, correlation_id="", msg_id="", timestamp="",
+                 msg_purpose="", sender_name="", sender_id="", receiver_name="",
+                 receiver_id="", reply_to="", reply_to_msg_id="", broker_url=DEFAULT_NATS_URL,
+                 metadata=None):
+        """
+        Initialize a MessageEnvelope.
+        
+        Args:
+            send_to: NATS subject/topic to publish the message to
+            payloads: List of MessagePayload objects
+            correlation_id: Unique identifier to track messages (auto-generated if empty)
+            msg_id: Unique message identifier (auto-generated if empty)
+            timestamp: Message publication timestamp
+            msg_purpose: Purpose of the message ("ACK", "NACK", "updateStatus", "shutdown", "chat", etc.)
+            sender_name: Name of the sender
+            sender_id: UUID of the sender
+            receiver_name: Name of the receiver (empty means broadcast)
+            receiver_id: UUID of the receiver (empty means broadcast)
+            reply_to: Topic where receiver should reply
+            reply_to_msg_id: Message ID this message is replying to
+            broker_url: NATS broker URL
+            metadata: Optional message-level metadata
+        """
+        self.correlation_id = correlation_id if correlation_id else self._generate_uuid()
+        self.msg_id = msg_id if msg_id else self._generate_uuid()
+        self.timestamp = timestamp if timestamp else self._get_timestamp()
+        self.send_to = send_to
+        self.msg_purpose = msg_purpose
+        self.sender_name = sender_name
+        self.sender_id = sender_id if sender_id else self._generate_uuid()
+        self.receiver_name = receiver_name
+        self.receiver_id = receiver_id if receiver_id else self._generate_uuid()
+        self.reply_to = reply_to
+        self.reply_to_msg_id = reply_to_msg_id
+        self.broker_url = broker_url
+        self.metadata = metadata if metadata else {}
+        self.payloads = payloads
+    
+    def _generate_uuid(self):
+        """Generate a UUID string."""
+        return str(uuid.uuid4())
+    
+    def _get_timestamp(self):
+        """Get current timestamp in ISO format."""
+        # Simplified timestamp - Micropython may not have full datetime
+        return "2026-02-21T" + time.strftime("%H:%M:%S", time.localtime())
+    
+    def to_json(self):
+        """Convert envelope to JSON string.
+        
+        Returns:
+            str: JSON string representation of the envelope using snake_case field names
+        """
+        obj = {
+            "correlation_id": self.correlation_id,
+            "msg_id": self.msg_id,
+            "timestamp": self.timestamp,
+            "send_to": self.send_to,
+            "msg_purpose": self.msg_purpose,
+            "sender_name": self.sender_name,
+            "sender_id": self.sender_id,
+            "receiver_name": self.receiver_name,
+            "receiver_id": self.receiver_id,
+            "reply_to": self.reply_to,
+            "reply_to_msg_id": self.reply_to_msg_id,
+            "broker_url": self.broker_url
+        }
+        
+        # Include metadata if not empty
+        if self.metadata:
+            obj["metadata"] = self.metadata
+        
+        # Convert payloads to JSON array
+        if self.payloads:
+            payloads_json = []
+            for payload in self.payloads:
+                payloads_json.append(payload.to_dict())
+            obj["payloads"] = payloads_json
+        
+        return json.dumps(obj)
+
+
+def log_trace(correlation_id, message):
+    """Log a trace message with correlation ID and timestamp."""
+    timestamp = time.strftime("%Y-%m-%dT%H:%M:%S", time.localtime())
+    print("[{}] [Correlation: {}] {}".format(timestamp, correlation_id, message))
+
+
+def _serialize_data(data, payload_type):
+    """Serialize data according to specified format.
+    
+    This function serializes arbitrary data into a binary representation based on the specified type.
+    It supports multiple serialization formats for different data types.
+    
+    Args:
+        data: Data to serialize
+            - "text": String
+            - "dictionary": JSON-serializable dict
+            - "table": Tabular data (pandas DataFrame or list of dicts)
+            - "image", "audio", "video", "binary": bytes
+        payload_type: Target format ("text", "dictionary", "table", "image", "audio", "video", "binary")
+    
+    Returns:
+        bytes: Binary representation of the serialized data
+    
+    Example:
+        >>> text_bytes = _serialize_data("Hello World", "text")
+        >>> json_bytes = _serialize_data({"key": "value"}, "dictionary")
+        >>> table_bytes = _serialize_data([{"id": 1, "name": "Alice"}], "table")
+    """
+    if payload_type == "text":
+        if isinstance(data, str):
+            return data.encode('utf-8')
+        else:
+            raise ValueError("Text data must be a string")
+    
+    elif payload_type == "dictionary":
+        if isinstance(data, dict):
+            json_str = json.dumps(data)
+            return json_str.encode('utf-8')
+        else:
+            raise ValueError("Dictionary data must be a dict")
+    
+    elif payload_type == "table":
+        # Support pandas DataFrame or list of dicts
+        try:
+            import pandas as pd
+            if isinstance(data, pd.DataFrame):
+                # Convert DataFrame to JSON and then to bytes
+                json_str = data.to_json(orient='records', force_ascii=False)
+                return json_str.encode('utf-8')
+            elif isinstance(data, list) and len(data) > 0 and isinstance(data[0], dict):
+                # List of dicts
+                json_str = json.dumps(data)
+                return json_str.encode('utf-8')
+            else:
+                raise ValueError("Table data must be a pandas DataFrame or list of dicts")
+        except ImportError:
+            # Fallback: if pandas not available, treat as list of dicts
+            if isinstance(data, list):
+                json_str = json.dumps(data)
+                return json_str.encode('utf-8')
+            else:
+                raise ValueError("Table data requires pandas DataFrame or list of dicts (pandas not available)")
+    
+    elif payload_type in ("image", "audio", "video", "binary"):
+        if isinstance(data, bytes):
+            return data
+        else:
+            raise ValueError("{} data must be bytes".format(payload_type.capitalize()))
+    
+    else:
+        raise ValueError("Unknown payload_type: {}".format(payload_type))
+
+
+def _deserialize_data(data_bytes, payload_type, correlation_id):
+    """Deserialize bytes to data based on type.
+    
+    This function converts serialized bytes back to Python data based on type.
+    It handles "text" (string), "dictionary" (JSON deserialization), "table" (JSON deserialization),
+    "image" (binary data), "audio" (binary data), "video" (binary data), and "binary" (binary data).
+    
+    Args:
+        data_bytes: Serialized data as bytes
+        payload_type: Data type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        Deserialized data:
+            - "text": str
+            - "dictionary": dict
+            - "table": list of dicts (or pandas DataFrame if available)
+            - "image", "audio", "video", "binary": bytes
+    
+    Example:
+        >>> text_data = _deserialize_data(b"Hello", "text", "corr_id")
+        >>> json_data = _deserialize_data(b'{"key": "value"}', "dictionary", "corr_id")
+        >>> table_data = _deserialize_data(b'[{"id": 1}]', "table", "corr_id")
+    """
+    if payload_type == "text":
+        return data_bytes.decode('utf-8')
+    
+    elif payload_type == "dictionary":
+        json_str = data_bytes.decode('utf-8')
+        return json.loads(json_str)
+    
+    elif payload_type == "table":
+        # Deserialize table data (JSON format)
+        json_str = data_bytes.decode('utf-8')
+        table_data = json.loads(json_str)
+        # If pandas is available, try to convert to DataFrame
+        try:
+            import pandas as pd
+            return pd.DataFrame(table_data)
+        except ImportError:
+            return table_data
+    
+    elif payload_type in ("image", "audio", "video", "binary"):
+        return data_bytes
+    
+    else:
+        raise ValueError("Unknown payload_type: {}".format(payload_type))
+
+
+class NATSConnection:
+    """Simple NATS connection for Python and Micropython."""
+    
+    def __init__(self, url=DEFAULT_BROKER_URL):
+        """Initialize NATS connection.
+        
+        Args:
+            url: NATS server URL (e.g., "nats://localhost:4222")
+        """
+        self.url = url
+        self.host = "localhost"
+        self.port = 4222
+        self.conn = None
+        self._parse_url(url)
+    
+    def _parse_url(self, url):
+        """Parse NATS URL to extract host and port."""
+        if url.startswith("nats://"):
+            url = url[7:]
+        elif url.startswith("tls://"):
+            url = url[6:]
+        
+        if ":" in url:
+            self.host, port_str = url.split(":")
+            self.port = int(port_str)
+        else:
+            self.host = url
+    
+    def connect(self):
+        """Connect to NATS server."""
+        # Use socket for both Python and Micropython
+        try:
+            import socket
+            addr = socket.getaddrinfo(self.host, self.port)[0][-1]
+            self.conn = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            self.conn.connect(addr)
+        except NameError:
+            # Micropython fallback
+            import usocket
+            addr = usocket.getaddrinfo(self.host, self.port)[0][-1]
+            self.conn = usocket.socket()
+            self.conn.connect(addr)
+        
+        log_trace("", "Connected to NATS server at {}:{}".format(self.host, self.port))
+    
+    def publish(self, subject, message):
+        """Publish a message to a NATS subject.
+        
+        Args:
+            subject: NATS subject to publish to
+            message: Message to publish (should be bytes or string)
+        """
+        if isinstance(message, str):
+            message = message.encode('utf-8')
+        
+        # Simple NATS protocol implementation
+        msg = "PUB {} {}\r\n".format(subject, len(message))
+        msg = msg.encode('utf-8') + message + b"\r\n"
+        
+        try:
+            import socket
+            self.conn.send(msg)
+        except NameError:
+            # Micropython fallback
+            import usocket
+            self.conn.send(msg)
+        
+        log_trace("", "Message published to {}".format(subject))
+    
+    def subscribe(self, subject, callback):
+        """Subscribe to a NATS subject.
+        
+        Args:
+            subject: NATS subject to subscribe to
+            callback: Callback function to handle incoming messages
+        """
+        log_trace("", "Subscribed to {}".format(subject))
+        # Simplified subscription - in a real implementation, you'd handle SUB/PUB messages
+        # For Micropython, we'll use a simple polling approach
+        self.subscribed_subject = subject
+        self.subscription_callback = callback
+    
+    def wait_message(self, timeout=1000):
+        """Wait for incoming message.
+        
+        Args:
+            timeout: Timeout in milliseconds
+            
+        Returns:
+            NATS message object or None if timeout
+        """
+        # Simplified message reading
+        # In a real implementation, you'd read from the socket
+        # For now, this is a placeholder
+        return None
+    
+    def close(self):
+        """Close the NATS connection."""
+        if self.conn:
+            self.conn.close()
+            self.conn = None
+            log_trace("", "NATS connection closed")
+
+
+def _fetch_with_backoff(url, max_retries=5, base_delay=100, max_delay=5000, correlation_id=""):
+    """Fetch data from URL with exponential backoff.
+    
+    This function retrieves data from a URL with retry logic using
+    exponential backoff to handle transient failures.
+    
+    Args:
+        url: URL to fetch from
+        max_retries: Maximum number of retry attempts (default: 5)
+        base_delay: Initial delay in milliseconds (default: 100)
+        max_delay: Maximum delay in milliseconds (default: 5000)
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        bytes: Fetched data
+    
+    Raises:
+        Exception: If all retry attempts fail
+    
+    Example:
+        >>> data = _fetch_with_backoff("http://example.com/file.zip", 5, 100, 5000, "corr_id")
+    """
+    delay = base_delay
+    for attempt in range(1, max_retries + 1):
+        try:
+            # Simple HTTP GET request
+            # Try urequests for Micropython first, then requests for Python
+            try:
+                import urequests
+                response = urequests.get(url)
+                status_code = response.status_code
+                content = response.content
+            except ImportError:
+                try:
+                    import requests
+                    response = requests.get(url)
+                    response.raise_for_status()
+                    status_code = response.status_code
+                    content = response.content
+                except ImportError:
+                    raise Exception("No HTTP library available (urequests or requests)")
+            
+            if status_code == 200:
+                log_trace(correlation_id, "Successfully fetched data from {} on attempt {}".format(url, attempt))
+                return content
+            else:
+                raise Exception("Failed to fetch: {}".format(status_code))
+        except Exception as e:
+            log_trace(correlation_id, "Attempt {} failed: {}".format(attempt, str(e)))
+            if attempt < max_retries:
+                time.sleep(delay / 1000.0)
+                delay = min(delay * 2, max_delay)
+    
+    raise Exception("Failed to fetch data after {} attempts".format(max_retries))
+
+
+def plik_oneshot_upload(fileserver_url, dataname, data):
+    """Upload a single file to a plik server using one-shot mode.
+    
+    This function uploads raw byte data to a plik server in one-shot mode (no upload session).
+    It first creates a one-shot upload session by sending a POST request with {"OneShot": true},
+    retrieves an upload ID and token, then uploads the file data as multipart form data using the token.
+    
+    Args:
+        fileserver_url: Base URL of the plik server (e.g., "http://localhost:8080")
+        dataname: Name of the file being uploaded
+        data: Raw byte data of the file content
+    
+    Returns:
+        dict: Dictionary with keys:
+            - "status": HTTP server response status
+            - "uploadid": ID of the one-shot upload session
+            - "fileid": ID of the uploaded file within the session
+            - "url": Full URL to download the uploaded file
+    
+    Example:
+        >>> result = plik_oneshot_upload("http://localhost:8080", "test.txt", b"hello world")
+        >>> result["status"], result["uploadid"], result["fileid"], result["url"]
+    """
+    import json
+    
+    try:
+        import urequests
+    except ImportError:
+        import requests as urequests
+    
+    # Get upload ID
+    url_get_upload_id = "{}/upload".format(fileserver_url)
+    headers = {"Content-Type": "application/json"}
+    body = json.dumps({"OneShot": True})
+    
+    response = urequests.post(url_get_upload_id, headers=headers, data=body)
+    response_json = json.loads(response.text if hasattr(response, 'text') else response.content)
+    
+    uploadid = response_json.get("id")
+    uploadtoken = response_json.get("uploadToken")
+    
+    # Upload file
+    url_upload = "{}/file/{}".format(fileserver_url, uploadid)
+    headers = {"X-UploadToken": uploadtoken}
+    
+    # For Micropython, we need to construct the multipart form data manually
+    # This is a simplified approach
+    boundary = "----WebKitFormBoundary{}".format(uuid.uuid4().hex[:16])
+    
+    # Create multipart body
+    part1 = "--{}\r\n".format(boundary)
+    part1 += "Content-Disposition: form-data; name=\"file\"; filename=\"{}\"\r\n".format(dataname)
+    part1 += "Content-Type: application/octet-stream\r\n\r\n"
+    part1_bytes = part1.encode('utf-8')
+    
+    part2 = "\r\n--{}--".format(boundary)
+    part2_bytes = part2.encode('utf-8')
+    
+    # Combine all parts
+    full_body = part1_bytes + data + part2_bytes
+    
+    # Set content type with boundary
+    content_type = "multipart/form-data; boundary={}".format(boundary)
+    
+    response = urequests.post(url_upload, headers={"Content-Type": content_type}, data=full_body)
+    response_json = json.loads(response.text if hasattr(response, 'text') else response.content)
+    
+    fileid = response_json.get("id")
+    url = "{}/file/{}/{}".format(fileserver_url, uploadid, dataname)
+    
+    return {
+        "status": response.status_code,
+        "uploadid": uploadid,
+        "fileid": fileid,
+        "url": url
+    }
+
+
+def smartsend(subject, data, broker_url=DEFAULT_BROKER_URL, fileserver_url=DEFAULT_FILESERVER_URL,
+              fileserver_upload_handler=plik_oneshot_upload, size_threshold=DEFAULT_SIZE_THRESHOLD,
+              correlation_id=None, msg_purpose="chat", sender_name="NATSBridge",
+              receiver_name="", receiver_id="", reply_to="", reply_to_msg_id="", is_publish=True):
+    """Send data either directly via NATS or via a fileserver URL, depending on payload size.
+    
+    This function intelligently routes data delivery based on payload size relative to a threshold.
+    If the serialized payload is smaller than `size_threshold`, it encodes the data as Base64 and 
+    publishes directly over NATS. Otherwise, it uploads the data to a fileserver and publishes 
+    only the download URL over NATS.
+    
+    Args:
+        subject: NATS subject to publish the message to
+        data: List of (dataname, data, payload_type) tuples to send
+            - dataname: Name of the payload
+            - data: The actual data to send
+            - payload_type: Payload type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+        broker_url: URL of the NATS server
+        fileserver_url: URL of the HTTP file server
+        fileserver_upload_handler: Function to handle fileserver uploads (must return dict with "status", "uploadid", "fileid", "url" keys)
+        size_threshold: Threshold in bytes separating direct vs link transport (default: 1MB)
+        correlation_id: Optional correlation ID for tracing; if None, a UUID is generated
+        msg_purpose: Purpose of the message ("ACK", "NACK", "updateStatus", "shutdown", "chat", etc.)
+        sender_name: Name of the sender
+        receiver_name: Name of the receiver (empty string means broadcast)
+        receiver_id: UUID of the receiver (empty string means broadcast)
+        reply_to: Topic to reply to (empty string if no reply expected)
+        reply_to_msg_id: Message ID this message is replying to
+        is_publish: Whether to automatically publish the message to NATS (default: True)
+            - When True: message is published to NATS
+            - When False: returns envelope and JSON string without publishing
+    
+    Returns:
+        tuple: (env, env_json_str) where:
+            - env: MessageEnvelope object with all metadata and payloads
+            - env_json_str: JSON string representation of the envelope for publishing
+    
+    Example:
+        >>> data = [("message", "Hello World!", "text")]
+        >>> env, env_json_str = smartsend("/test", data)
+        >>> # env: MessageEnvelope with all metadata and payloads
+        >>> # env_json_str: JSON string for publishing
+    """
+    # Generate correlation ID if not provided
+    cid = correlation_id if correlation_id is not None else str(uuid.uuid4())
+    
+    log_trace(cid, "Starting smartsend for subject: {}".format(subject))
+    
+    # Generate message metadata
+    msg_id = str(uuid.uuid4())
+    
+    # Process each payload in the list
+    payloads = []
+    
+    for dataname, payload_data, payload_type in data:
+        # Serialize data based on type
+        payload_bytes = _serialize_data(payload_data, payload_type)
+        
+        payload_size = len(payload_bytes)
+        log_trace(cid, "Serialized payload '{}' (payload_type: {}) size: {} bytes".format(
+            dataname, payload_type, payload_size))
+        
+        # Decision: Direct vs Link
+        if payload_size < size_threshold:
+            # Direct path - Base64 encode and send via NATS
+            # Convert to base64 string for JSON
+            try:
+                import ubinascii
+                payload_b64_str = ubinascii.b2a_base64(payload_bytes).decode('utf-8').strip()
+            except ImportError:
+                import base64
+                payload_b64_str = base64.b64encode(payload_bytes).decode('utf-8')
+            
+            log_trace(cid, "Using direct transport for {} bytes".format(payload_size))
+            
+            # Create MessagePayload for direct transport
+            payload = MessagePayload(
+                payload_b64_str,
+                payload_type,
+                id=str(uuid.uuid4()),
+                dataname=dataname,
+                transport="direct",
+                encoding="base64",
+                size=payload_size,
+                metadata={"payload_bytes": payload_size}
+            )
+            payloads.append(payload)
+        else:
+            # Link path - Upload to HTTP server, send URL via NATS
+            log_trace(cid, "Using link transport, uploading to fileserver")
+            
+            # Upload to HTTP server
+            response = fileserver_upload_handler(fileserver_url, dataname, payload_bytes)
+            
+            if response.get("status") != 200:
+                raise Exception("Failed to upload data to fileserver: {}".format(response.get("status")))
+            
+            url = response.get("url")
+            log_trace(cid, "Uploaded to URL: {}".format(url))
+            
+            # Create MessagePayload for link transport
+            payload = MessagePayload(
+                url,
+                payload_type,
+                id=str(uuid.uuid4()),
+                dataname=dataname,
+                transport="link",
+                encoding="none",
+                size=payload_size,
+                metadata={}
+            )
+            payloads.append(payload)
+    
+    # Create MessageEnvelope with all payloads
+    env = MessageEnvelope(
+        subject,
+        payloads,
+        correlation_id=cid,
+        msg_id=msg_id,
+        msg_purpose=msg_purpose,
+        sender_name=sender_name,
+        sender_id=str(uuid.uuid4()),
+        receiver_name=receiver_name,
+        receiver_id=receiver_id,
+        reply_to=reply_to,
+        reply_to_msg_id=reply_to_msg_id,
+        broker_url=broker_url,
+        metadata={}
+    )
+    
+    msg_json = env.to_json()
+    
+    # Publish to NATS if is_publish is True
+    if is_publish:
+        nats_conn = NATSConnection(broker_url)
+        nats_conn.connect()
+        nats_conn.publish(subject, msg_json)
+        nats_conn.close()
+    
+    # Return tuple of (envelope, json_string) for both direct and link transport
+    return (env, msg_json)
+
+
+def smartreceive(msg, fileserver_download_handler=_fetch_with_backoff, max_retries=5,
+                  base_delay=100, max_delay=5000):
+    """Receive and process messages from NATS.
+    
+    This function processes incoming NATS messages, handling both direct transport
+    (base64 decoded payloads) and link transport (URL-based payloads).
+    
+    Args:
+        msg: NATS message to process (dict or JSON string with envelope data)
+        fileserver_download_handler: Function to handle downloading data from file server URLs
+            Receives: (url, max_retries, base_delay, max_delay, correlation_id)
+            Returns: bytes (the downloaded data)
+        max_retries: Maximum retry attempts for fetching URL (default: 5)
+        base_delay: Initial delay for exponential backoff in ms (default: 100)
+        max_delay: Maximum delay for exponential backoff in ms (default: 5000)
+    
+    Returns:
+        dict: Envelope dictionary with metadata and 'payloads' field containing list of 
+              (dataname, data, payload_type) tuples
+    
+    Example:
+        >>> env = smartreceive(msg)
+        >>> # env contains envelope metadata and payloads field
+        >>> # env["payloads"] = [(dataname1, data1, payload_type1), ...]
+        >>> for dataname, data, payload_type in env["payloads"]:
+        ...     print("Received {} of type {}: {}".format(dataname, payload_type, data))
+    """
+    # Parse the JSON envelope
+    json_data = msg if isinstance(msg, dict) else json.loads(msg)
+    correlation_id = json_data.get("correlation_id", "")
+    log_trace(correlation_id, "Processing received message")
+    
+    # Process all payloads in the envelope
+    payloads_list = []
+    
+    # Get number of payloads
+    num_payloads = len(json_data.get("payloads", []))
+    
+    for i in range(num_payloads):
+        payload = json_data["payloads"][i]
+        transport = payload.get("transport", "")
+        dataname = payload.get("dataname", "")
+        
+        if transport == "direct":
+            log_trace(correlation_id, 
+                     "Direct transport - decoding payload '{}'".format(dataname))
+            
+            # Extract base64 payload from the payload
+            payload_b64 = payload.get("data", "")
+            
+            # Decode Base64 payload
+            try:
+                import ubinascii
+                payload_bytes = ubinascii.a2b_base64(payload_b64.encode('utf-8'))
+            except ImportError:
+                import base64
+                payload_bytes = base64.b64decode(payload_b64)
+            
+            # Deserialize based on type
+            payload_type = payload.get("payload_type", "")
+            data = _deserialize_data(payload_bytes, payload_type, correlation_id)
+            
+            payloads_list.append((dataname, data, payload_type))
+            
+        elif transport == "link":
+            # Extract download URL from the payload
+            url = payload.get("data", "")
+            log_trace(correlation_id,
+                      "Link transport - fetching '{}' from URL: {}".format(dataname, url))
+            
+            # Fetch with exponential backoff
+            downloaded_data = fileserver_download_handler(
+                url, max_retries, base_delay, max_delay, correlation_id
+            )
+            
+            # Deserialize based on type
+            payload_type = payload.get("payload_type", "")
+            data = _deserialize_data(downloaded_data, payload_type, correlation_id)
+            
+            payloads_list.append((dataname, data, payload_type))
+            
+        else:
+            raise ValueError("Unknown transport type for payload '{}': {}".format(dataname, transport))
+    
+    # Replace payloads field with the processed list of (dataname, data, payload_type) tuples
+    json_data["payloads"] = payloads_list
+    
+    return json_data
+
+
+# Utility functions
+def generate_uuid():
+    """Generate a UUID string."""
+    return str(uuid.uuid4())
+
+
+def get_timestamp():
+    """Get current timestamp in ISO format."""
+    return time.strftime("%Y-%m-%dT%H:%M:%S", time.localtime())
+
+
+# Example usage
+if __name__ == "__main__":
+    print("NATSBridge - Bi-Directional Data Bridge")
+    print("=======================================")
+    print("This module provides:")
+    print("  - MessageEnvelope: Message envelope structure with snake_case fields")
+    print("  - MessagePayload: Payload structure with payload_type field")
+    print("  - smartsend: Send data via NATS with automatic transport selection")
+    print("  - smartreceive: Receive and process messages from NATS")
+    print("  - plik_oneshot_upload: Upload files to HTTP file server")
+    print("  - _fetch_with_backoff: Fetch data from URLs with retry logic")
+    print()
+    print("Usage:")
+    print("  from nats_bridge import smartsend, smartreceive")
+    print()
+    print("  # Send data (list of (dataname, data, payload_type) tuples)")
+    print("  data = [(\"message\", \"Hello World!\", \"text\")]")
+    print("  env, env_json_str = smartsend(\"my.subject\", data)")
+    print()
+    print("  # On receiver:")
+    print("  env = smartreceive(msg)")
+    print("  for dataname, data, payload_type in env[\"payloads\"]:")
+    print("      print(\"Received {} of type {}: {}\".format(dataname, payload_type, data))")

test/scenario1_command_control.jl

@@ -1,67 +0,0 @@
-#!/usr/bin/env julia
-# Scenario 1: Command & Control (Small JSON)
-# Tests small JSON payloads (< 1MB) sent directly via NATS
-
-using NATS
-using JSON3
-using UUIDs
-
-# Include the bridge module
-include("../src/julia_bridge.jl")
-using .BiDirectionalBridge
-
-# Configuration
-const CONTROL_SUBJECT = "control"
-const RESPONSE_SUBJECT = "control_response"
-const NATS_URL = "nats://localhost:4222"
-
-# Create correlation ID for tracing
-correlation_id = string(uuid4())
-
-# Receiver: Listen for control commands
-function start_control_listener()
-    conn = NATS.Connection(NATS_URL)
-    try
-        NATS.subscribe(conn, CONTROL_SUBJECT) do msg
-            log_trace(msg.data)
-            
-            # Parse the envelope
-            env = MessageEnvelope(String(msg.data))
-            
-            # Parse JSON payload
-            config = JSON3.read(env.payload)
-            
-            # Execute simulation with parameters
-            step_size = config.step_size
-            iterations = config.iterations
-            
-            # Simulate processing
-            sleep(0.1)  # Simulate some work
-            
-            # Send acknowledgment
-            response = Dict(
-                "status" => "Running",
-                "correlation_id" => env.correlation_id,
-                "step_size" => step_size,
-                "iterations" => iterations
-            )
-            
-            NATS.publish(conn, RESPONSE_SUBJECT, JSON3.stringify(response))
-            log_trace("Sent response: $(JSON3.stringify(response))")
-        end
-        
-        # Keep listening for 5 seconds
-        sleep(5)
-    finally
-        NATS.close(conn)
-    end
-end
-
-# Helper: Log with correlation ID
-function log_trace(message)
-    timestamp = Dates.now()
-    println("[$timestamp] [Correlation: $correlation_id] $message")
-end
-
-# Run the listener
-start_control_listener()

test/scenario1_command_control.js

@@ -1,34 +0,0 @@
-#!/usr/bin/env node
-// Scenario 1: Command & Control (Small JSON)
-// Tests small JSON payloads (< 1MB) sent directly via NATS
-
-const { SmartSend } = require('../js_bridge');
-
-// Configuration
-const CONTROL_SUBJECT = "control";
-const NATS_URL = "nats://localhost:4222";
-
-// Create correlation ID for tracing
-const correlationId = require('uuid').v4();
-
-// Sender: Send control command to Julia
-async function sendControlCommand() {
-    const config = {
-        step_size: 0.01,
-        iterations: 1000
-    };
-
-    // Send via SmartSend with type="json"
-    const env = await SmartSend(
-        CONTROL_SUBJECT,
-        config,
-        "json",
-        { correlationId }
-    );
-
-    console.log(`Sent control command with correlation_id: ${correlationId}`);
-    console.log(`Envelope: ${JSON.stringify(env, null, 2)}`);
-}
-
-// Run the sender
-sendControlCommand().catch(console.error);

test/scenario2_large_table.jl

@@ -1,66 +0,0 @@
-#!/usr/bin/env julia
-# Scenario 2: Deep Dive Analysis (Large Arrow Table)
-# Tests large Arrow tables (> 1MB) sent via HTTP fileserver
-
-using NATS
-using Arrow
-using DataFrames
-using JSON3
-using UUIDs
-
-# Include the bridge module
-include("../src/julia_bridge.jl")
-using .BiDirectionalBridge
-
-# Configuration
-const ANALYSIS_SUBJECT = "analysis_results"
-const RESPONSE_SUBJECT = "analysis_response"
-const NATS_URL = "nats://localhost:4222"
-
-# Create correlation ID for tracing
-correlation_id = string(uuid4())
-
-# Receiver: Listen for analysis results
-function start_analysis_listener()
-    conn = NATS.Connection(NATS_URL)
-    try
-        NATS.subscribe(conn, ANALYSIS_SUBJECT) do msg
-            log_trace("Received message from $(msg.subject)")
-            
-            # Parse the envelope
-            env = MessageEnvelope(String(msg.data))
-            
-            # Use SmartReceive to handle the data
-            result = SmartReceive(msg)
-            
-            # Process the data based on type
-            if result.envelope.type == "table"
-                df = result.data
-                log_trace("Received DataFrame with $(nrows(df)) rows")
-                log_trace("DataFrame columns: $(names(df))")
-                
-                # Send acknowledgment
-                response = Dict(
-                    "status" => "Processed",
-                    "correlation_id" => env.correlation_id,
-                    "row_count" => nrows(df)
-                )
-                NATS.publish(conn, RESPONSE_SUBJECT, JSON3.stringify(response))
-            end
-        end
-        
-        # Keep listening for 10 seconds
-        sleep(10)
-    finally
-        NATS.close(conn)
-    end
-end
-
-# Helper: Log with correlation ID
-function log_trace(message)
-    timestamp = Dates.now()
-    println("[$timestamp] [Correlation: $correlation_id] $message")
-end
-
-# Run the listener
-start_analysis_listener()

test/scenario2_large_table.js

@@ -1,54 +0,0 @@
-#!/usr/bin/env node
-// Scenario 2: Deep Dive Analysis (Large Arrow Table)
-// Tests large Arrow tables (> 1MB) sent via HTTP fileserver
-
-const { SmartSend } = require('../js_bridge');
-
-// Configuration
-const ANALYSIS_SUBJECT = "analysis_results";
-const NATS_URL = "nats://localhost:4222";
-
-// Create correlation ID for tracing
-const correlationId = require('uuid').v4();
-
-// Sender: Send large Arrow table to Julia
-async function sendLargeTable() {
-    // Create a large DataFrame-like structure (10 million rows)
-    // For testing, we'll create a smaller but still large table
-    const numRows = 1000000; // 1 million rows
-    
-    const data = {
-        id: Array.from({ length: numRows }, (_, i) => i + 1),
-        value: Array.from({ length: numRows }, () => Math.random()),
-        category: Array.from({ length: numRows }, () => ['A', 'B', 'C'][Math.floor(Math.random() * 3)])
-    };
-    
-    // Convert to Arrow Table
-    const { Table, Vector, RecordBatch } = require('apache-arrow');
-    
-    const idVector = Vector.from(data.id);
-    const valueVector = Vector.from(data.value);
-    const categoryVector = Vector.from(data.category);
-    
-    const table = Table.from({
-        id: idVector,
-        value: valueVector,
-        category: categoryVector
-    });
-    
-    // Send via SmartSend with type="table"
-    const env = await SmartSend(
-        ANALYSIS_SUBJECT,
-        table,
-        "table",
-        { correlationId }
-    );
-    
-    console.log(`Sent large table with ${numRows} rows`);
-    console.log(`Correlation ID: ${correlationId}`);
-    console.log(`Transport: ${env.transport}`);
-    console.log(`URL: ${env.url || 'N/A'}`);
-}
-
-// Run the sender
-sendLargeTable().catch(console.error);

test/test_js_dict_receiver.js

@@ -0,0 +1,80 @@
+#!/usr/bin/env node
+// Test script for Dictionary transport testing
+// Tests receiving 1 large and 1 small Dictionaries via direct and link transport
+// Uses NATSBridge.js smartreceive with "dictionary" type
+
+const { smartreceive, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_dict_test";
+const NATS_URL = "nats.yiem.cc";
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] ${message}`);
+}
+
+// Receiver: Listen for messages and verify Dictionary handling
+async function test_dict_receive() {
+    // Connect to NATS
+    const { connect } = require('nats');
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        log_trace(`Received message on ${msg.subject}`);
+        
+        // Use NATSBridge.smartreceive to handle the data
+        const result = await smartreceive(
+            msg,
+            {
+                maxRetries: 5,
+                baseDelay: 100,
+                maxDelay: 5000
+            }
+        );
+        
+        // Result is an envelope dictionary with payloads field
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
+            if (typeof data === 'object' && data !== null && !Array.isArray(data)) {
+                log_trace(`Received Dictionary '${dataname}' of type ${type}`);
+                
+                // Display dictionary contents
+                console.log("  Contents:");
+                for (const [key, value] of Object.entries(data)) {
+                    console.log(`    ${key} => ${value}`);
+                }
+                
+                // Save to JSON file
+                const fs = require('fs');
+                const output_path = `./received_${dataname}.json`;
+                const json_str = JSON.stringify(data, null, 2);
+                fs.writeFileSync(output_path, json_str);
+                log_trace(`Saved Dictionary to ${output_path}`);
+            } else {
+                log_trace(`Received unexpected data type for '${dataname}': ${typeof data}`);
+            }
+        }
+    }
+    
+    // Keep listening for 10 seconds
+    setTimeout(() => {
+        nc.close();
+        process.exit(0);
+    }, 120000);
+}
+
+// Run the test
+console.log("Starting Dictionary transport test...");
+console.log("Note: This receiver will wait for messages from the sender.");
+console.log("Run test_js_to_js_dict_sender.js first to send test data.");
+
+// Run receiver
+console.log("testing smartreceive");
+test_dict_receive();
+
+console.log("Test completed.");

test/test_js_dict_sender.js

@@ -0,0 +1,165 @@
+#!/usr/bin/env node
+// Test script for Dictionary transport testing
+// Tests sending 1 large and 1 small Dictionaries via direct and link transport
+// Uses NATSBridge.js smartsend with "dictionary" type
+
+const { smartsend, uuid4, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_dict_test";
+const NATS_URL = "nats.yiem.cc";
+const FILESERVER_URL = "http://192.168.88.104:8080";
+
+// Create correlation ID for tracing
+const correlation_id = uuid4();
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
+}
+
+// File upload handler for plik server
+async function plik_upload_handler(fileserver_url, dataname, data, correlation_id) {
+    // Get upload ID
+    const url_getUploadID = `${fileserver_url}/upload`;
+    const headers = {
+        "Content-Type": "application/json"
+    };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to get upload ID: ${response.status} ${response.statusText}`);
+    }
+    
+    const responseJson = await response.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+    
+    // Upload file
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    response = await fetch(`${fileserver_url}/file/${uploadid}`, {
+        method: "POST",
+        headers: {
+            "X-UploadToken": uploadtoken
+        },
+        body: formData
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to upload file: ${response.status} ${response.statusText}`);
+    }
+    
+    const fileResponseJson = await response.json();
+    const fileid = fileResponseJson.id;
+    
+    const url = `${fileserver_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    return {
+        status: response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Sender: Send Dictionaries via smartsend
+async function test_dict_send() {
+    // Create a small Dictionary (will use direct transport)
+    const small_dict = {
+        name: "Alice",
+        age: 30,
+        scores: [95, 88, 92],
+        metadata: {
+            height: 155,
+            weight: 55
+        }
+    };
+    
+    // Create a large Dictionary (will use link transport if > 1MB)
+    const large_dict_ids = [];
+    const large_dict_names = [];
+    const large_dict_scores = [];
+    const large_dict_categories = [];
+    
+    for (let i = 0; i < 50000; i++) {
+        large_dict_ids.push(i + 1);
+        large_dict_names.push(`User_${i}`);
+        large_dict_scores.push(Math.floor(Math.random() * 100) + 1);
+        large_dict_categories.push(`Category_${Math.floor(Math.random() * 10) + 1}`);
+    }
+    
+    const large_dict = {
+        ids: large_dict_ids,
+        names: large_dict_names,
+        scores: large_dict_scores,
+        categories: large_dict_categories,
+        metadata: {
+            source: "test_generator",
+            timestamp: new Date().toISOString()
+        }
+    };
+    
+    // Test data 1: small Dictionary
+    const data1 = { dataname: "small_dict", data: small_dict, type: "dictionary" };
+    
+    // Test data 2: large Dictionary
+    const data2 = { dataname: "large_dict", data: large_dict, type: "dictionary" };
+    
+    // Use smartsend with dictionary type
+    // For small Dictionary: will use direct transport (JSON encoded)
+    // For large Dictionary: will use link transport (uploaded to fileserver)
+    const { env, env_json_str } = await smartsend(
+        SUBJECT,
+        [data1, data2],
+        {
+            natsUrl: NATS_URL,
+            fileserverUrl: FILESERVER_URL,
+            fileserverUploadHandler: plik_upload_handler,
+            sizeThreshold: 1_000_000,
+            correlationId: correlation_id,
+            msgPurpose: "chat",
+            senderName: "dict_sender",
+            receiverName: "",
+            receiverId: "",
+            replyTo: "",
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
+        }
+    );
+    
+    log_trace(`Sent message with ${env.payloads.length} payloads`);
+    
+    // Log transport type for each payload
+    for (let i = 0; i < env.payloads.length; i++) {
+        const payload = env.payloads[i];
+        log_trace(`Payload ${i + 1} ('${payload.dataname}'):`);
+        log_trace(`  Transport: ${payload.transport}`);
+        log_trace(`  Type: ${payload.type}`);
+        log_trace(`  Size: ${payload.size} bytes`);
+        log_trace(`  Encoding: ${payload.encoding}`);
+        
+        if (payload.transport === "link") {
+            log_trace(`  URL: ${payload.data}`);
+        }
+    }
+}
+
+// Run the test
+console.log("Starting Dictionary transport test...");
+console.log(`Correlation ID: ${correlation_id}`);
+
+// Run sender
+console.log("start smartsend for dictionaries");
+test_dict_send();
+
+console.log("Test completed.");

test/test_js_file_receiver.js

@@ -0,0 +1,71 @@
+#!/usr/bin/env node
+// Test script for large payload testing using binary transport
+// Tests receiving a large file (> 1MB) via smartsend with binary type
+
+const { smartreceive, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_test";
+const NATS_URL = "nats.yiem.cc";
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] ${message}`);
+}
+
+// Receiver: Listen for messages and verify large payload handling
+async function test_large_binary_receive() {
+    // Connect to NATS
+    const { connect } = require('nats');
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        log_trace(`Received message on ${msg.subject}`);
+        
+        // Use NATSBridge.smartreceive to handle the data
+        const result = await smartreceive(
+            msg,
+            {
+                maxRetries: 5,
+                baseDelay: 100,
+                maxDelay: 5000
+            }
+        );
+        
+        // Result is an envelope dictionary with payloads field
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
+            if (data instanceof Uint8Array || Array.isArray(data)) {
+                const file_size = data.length;
+                log_trace(`Received ${file_size} bytes of binary data for '${dataname}' of type ${type}`);
+                
+                // Save received data to a test file
+                const fs = require('fs');
+                const output_path = `./new_${dataname}`;
+                fs.writeFileSync(output_path, Buffer.from(data));
+                log_trace(`Saved received data to ${output_path}`);
+            } else {
+                log_trace(`Received unexpected data type for '${dataname}': ${typeof data}`);
+            }
+        }
+    }
+    
+    // Keep listening for 10 seconds
+    setTimeout(() => {
+        nc.close();
+        process.exit(0);
+    }, 120000);
+}
+
+// Run the test
+console.log("Starting large binary payload test...");
+
+// Run receiver
+console.log("testing smartreceive");
+test_large_binary_receive();
+
+console.log("Test completed.");

test/test_js_file_sender.js

@@ -0,0 +1,144 @@
+#!/usr/bin/env node
+// Test script for large payload testing using binary transport
+// Tests sending a large file (> 1MB) via smartsend with binary type
+
+const { smartsend, uuid4, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_test";
+const NATS_URL = "nats.yiem.cc";
+const FILESERVER_URL = "http://192.168.88.104:8080";
+
+// Create correlation ID for tracing
+const correlation_id = uuid4();
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
+}
+
+// File upload handler for plik server
+async function plik_upload_handler(fileserver_url, dataname, data, correlation_id) {
+    log_trace(correlation_id, `Uploading ${dataname} to fileserver: ${fileserver_url}`);
+    
+    // Step 1: Get upload ID and token
+    const url_getUploadID = `${fileserver_url}/upload`;
+    const headers = {
+        "Content-Type": "application/json"
+    };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to get upload ID: ${response.status} ${response.statusText}`);
+    }
+    
+    const responseJson = await response.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+    
+    // Step 2: Upload file data
+    const url_upload = `${fileserver_url}/file/${uploadid}`;
+    
+    // Create multipart form data
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    response = await fetch(url_upload, {
+        method: "POST",
+        headers: {
+            "X-UploadToken": uploadtoken
+        },
+        body: formData
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to upload file: ${response.status} ${response.statusText}`);
+    }
+    
+    const fileResponseJson = await response.json();
+    const fileid = fileResponseJson.id;
+    
+    // Build the download URL
+    const url = `${fileserver_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    log_trace(correlation_id, `Uploaded to URL: ${url}`);
+    
+    return {
+        status: response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Sender: Send large binary file via smartsend
+async function test_large_binary_send() {
+    // Read the large file as binary data
+    const fs = require('fs');
+    
+    // Test data 1
+    const file_path1 = './testFile_large.zip';
+    const file_data1 = fs.readFileSync(file_path1);
+    const filename1 = 'testFile_large.zip';
+    const data1 = { dataname: filename1, data: file_data1, type: "binary" };
+    
+    // Test data 2
+    const file_path2 = './testFile_small.zip';
+    const file_data2 = fs.readFileSync(file_path2);
+    const filename2 = 'testFile_small.zip';
+    const data2 = { dataname: filename2, data: file_data2, type: "binary" };
+    
+    // Use smartsend with binary type - will automatically use link transport
+    // if file size exceeds the threshold (1MB by default)
+    const { env, env_json_str } = await smartsend(
+        SUBJECT,
+        [data1, data2],
+        {
+            natsUrl: NATS_URL,
+            fileserverUrl: FILESERVER_URL,
+            fileserverUploadHandler: plik_upload_handler,
+            sizeThreshold: 1_000_000,
+            correlationId: correlation_id,
+            msgPurpose: "chat",
+            senderName: "sender",
+            receiverName: "",
+            receiverId: "",
+            replyTo: "",
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
+        }
+    );
+    
+    log_trace(`Sent message with transport: ${env.payloads[0].transport}`);
+    log_trace(`Envelope type: ${env.payloads[0].type}`);
+    
+    // Check if link transport was used
+    if (env.payloads[0].transport === "link") {
+        log_trace("Using link transport - file uploaded to HTTP server");
+        log_trace(`URL: ${env.payloads[0].data}`);
+    } else {
+        log_trace("Using direct transport - payload sent via NATS");
+    }
+}
+
+// Run the test
+console.log("Starting large binary payload test...");
+console.log(`Correlation ID: ${correlation_id}`);
+
+// Run sender first
+console.log("start smartsend");
+test_large_binary_send();
+
+// Run receiver
+// console.log("testing smartreceive");
+// test_large_binary_receive();
+
+console.log("Test completed.");

test/test_js_mix_payload_sender.js

@@ -0,0 +1,277 @@
+#!/usr/bin/env node
+// Test script for mixed-content message testing
+// Tests sending a mix of text, json, table, image, audio, video, and binary data
+// from JavaScript serviceA to JavaScript serviceB using NATSBridge.js smartsend
+//
+// This test demonstrates that any combination and any number of mixed content
+// can be sent and received correctly.
+
+const { smartsend, uuid4, log_trace, _serialize_data } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_mix_test";
+const NATS_URL = "nats.yiem.cc";
+const FILESERVER_URL = "http://192.168.88.104:8080";
+
+// Create correlation ID for tracing
+const correlation_id = uuid4();
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
+}
+
+// File upload handler for plik server
+async function plik_upload_handler(fileserver_url, dataname, data, correlation_id) {
+    log_trace(correlation_id, `Uploading ${dataname} to fileserver: ${fileserver_url}`);
+    
+    // Step 1: Get upload ID and token
+    const url_getUploadID = `${fileserver_url}/upload`;
+    const headers = {
+        "Content-Type": "application/json"
+    };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to get upload ID: ${response.status} ${response.statusText}`);
+    }
+    
+    const responseJson = await response.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+    
+    // Step 2: Upload file data
+    const url_upload = `${fileserver_url}/file/${uploadid}`;
+    
+    // Create multipart form data
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    response = await fetch(url_upload, {
+        method: "POST",
+        headers: {
+            "X-UploadToken": uploadtoken
+        },
+        body: formData
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to upload file: ${response.status} ${response.statusText}`);
+    }
+    
+    const fileResponseJson = await response.json();
+    const fileid = fileResponseJson.id;
+    
+    // Build the download URL
+    const url = `${fileserver_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    log_trace(correlation_id, `Uploaded to URL: ${url}`);
+    
+    return {
+        status: response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Helper: Create sample data for each type
+function create_sample_data() {
+    // Text data (small - direct transport)
+    const text_data = "Hello! This is a test chat message. 🎉\nHow are you doing today? 😊";
+    
+    // Dictionary/JSON data (medium - could be direct or link)
+    const dict_data = {
+        type: "chat",
+        sender: "serviceA",
+        receiver: "serviceB",
+        metadata: {
+            timestamp: new Date().toISOString(),
+            priority: "high",
+            tags: ["urgent", "chat", "test"]
+        },
+        content: {
+            text: "This is a JSON-formatted chat message with nested structure.",
+            format: "markdown",
+            mentions: ["user1", "user2"]
+        }
+    };
+    
+    // Table data (small - direct transport) - NOT IMPLEMENTED (requires apache-arrow)
+    // const table_data_small = {...};
+    
+    // Table data (large - link transport) - NOT IMPLEMENTED (requires apache-arrow)
+    // const table_data_large = {...};
+    
+    // Image data (small binary - direct transport)
+    // Create a simple 10x10 pixel PNG-like data
+    const image_width = 10;
+    const image_height = 10;
+    let image_data = new Uint8Array(128);  // PNG header + pixel data
+    // PNG header
+    image_data[0] = 0x89;
+    image_data[1] = 0x50;
+    image_data[2] = 0x4E;
+    image_data[3] = 0x47;
+    image_data[4] = 0x0D;
+    image_data[5] = 0x0A;
+    image_data[6] = 0x1A;
+    image_data[7] = 0x0A;
+    // Simple RGB data (10*10*3 = 300 bytes)
+    for (let i = 0; i < 300; i++) {
+        image_data[i + 8] = 0xFF;  // Red pixel
+    }
+    
+    // Image data (large - link transport)
+    const large_image_width = 500;
+    const large_image_height = 1000;
+    const large_image_data = new Uint8Array(large_image_width * large_image_height * 3 + 8);
+    // PNG header
+    large_image_data[0] = 0x89;
+    large_image_data[1] = 0x50;
+    large_image_data[2] = 0x4E;
+    large_image_data[3] = 0x47;
+    large_image_data[4] = 0x0D;
+    large_image_data[5] = 0x0A;
+    large_image_data[6] = 0x1A;
+    large_image_data[7] = 0x0A;
+    // Random RGB data
+    for (let i = 0; i < large_image_width * large_image_height * 3; i++) {
+        large_image_data[i + 8] = Math.floor(Math.random() * 255);
+    }
+    
+    // Audio data (small binary - direct transport)
+    const audio_data = new Uint8Array(100);
+    for (let i = 0; i < 100; i++) {
+        audio_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    // Audio data (large - link transport)
+    const large_audio_data = new Uint8Array(1_500_000);
+    for (let i = 0; i < 1_500_000; i++) {
+        large_audio_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    // Video data (small binary - direct transport)
+    const video_data = new Uint8Array(150);
+    for (let i = 0; i < 150; i++) {
+        video_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    // Video data (large - link transport)
+    const large_video_data = new Uint8Array(1_500_000);
+    for (let i = 0; i < 1_500_000; i++) {
+        large_video_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    // Binary data (small - direct transport)
+    const binary_data = new Uint8Array(200);
+    for (let i = 0; i < 200; i++) {
+        binary_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    // Binary data (large - link transport)
+    const large_binary_data = new Uint8Array(1_500_000);
+    for (let i = 0; i < 1_500_000; i++) {
+        large_binary_data[i] = Math.floor(Math.random() * 255);
+    }
+    
+    return {
+        text_data,
+        dict_data,
+        // table_data_small,
+        // table_data_large,
+        image_data,
+        large_image_data,
+        audio_data,
+        large_audio_data,
+        video_data,
+        large_video_data,
+        binary_data,
+        large_binary_data
+    };
+}
+
+// Sender: Send mixed content via smartsend
+async function test_mix_send() {
+    // Create sample data
+    const { text_data, dict_data, image_data, large_image_data, audio_data, large_audio_data, video_data, large_video_data, binary_data, large_binary_data } = create_sample_data();
+    
+    // Create payloads list - mixed content with both small and large data
+    // Small data uses direct transport, large data uses link transport
+    const payloads = [
+        // Small data (direct transport) - text, dictionary
+        { dataname: "chat_text", data: text_data, type: "text" },
+        { dataname: "chat_json", data: dict_data, type: "dictionary" },
+        // { dataname: "chat_table_small", data: table_data_small, type: "table" },
+        
+        // Large data (link transport) - large image, large audio, large video, large binary
+        // { dataname: "chat_table_large", data: table_data_large, type: "table" },
+        { dataname: "user_image_large", data: large_image_data, type: "image" },
+        { dataname: "audio_clip_large", data: large_audio_data, type: "audio" },
+        { dataname: "video_clip_large", data: large_video_data, type: "video" },
+        { dataname: "binary_file_large", data: large_binary_data, type: "binary" }
+    ];
+    
+    // Use smartsend with mixed content
+    const { env, env_json_str } = await smartsend(
+        SUBJECT,
+        payloads,
+        {
+            natsUrl: NATS_URL,
+            fileserverUrl: FILESERVER_URL,
+            fileserverUploadHandler: plik_upload_handler,
+            sizeThreshold: 1_000_000,
+            correlationId: correlation_id,
+            msgPurpose: "chat",
+            senderName: "mix_sender",
+            receiverName: "",
+            receiverId: "",
+            replyTo: "",
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
+        }
+    );
+    
+    log_trace(`Sent message with ${env.payloads.length} payloads`);
+    
+    // Log transport type for each payload
+    for (let i = 0; i < env.payloads.length; i++) {
+        const payload = env.payloads[i];
+        log_trace(`Payload ${i + 1} ('${payload.dataname}'):`);
+        log_trace(`  Transport: ${payload.transport}`);
+        log_trace(`  Type: ${payload.type}`);
+        log_trace(`  Size: ${payload.size} bytes`);
+        log_trace(`  Encoding: ${payload.encoding}`);
+        
+        if (payload.transport === "link") {
+            log_trace(`  URL: ${payload.data}`);
+        }
+    }
+    
+    // Summary
+    console.log("\n--- Transport Summary ---");
+    const direct_count = env.payloads.filter(p => p.transport === "direct").length;
+    const link_count = env.payloads.filter(p => p.transport === "link").length;
+    log_trace(`Direct transport: ${direct_count} payloads`);
+    log_trace(`Link transport: ${link_count} payloads`);
+}
+
+// Run the test
+console.log("Starting mixed-content transport test...");
+console.log(`Correlation ID: ${correlation_id}`);
+
+// Run sender
+console.log("start smartsend for mixed content");
+test_mix_send();
+
+console.log("\nTest completed.");
+console.log("Note: Run test_js_to_js_mix_receiver.js to receive the messages.");

test/test_js_mix_payloads_receiver.js

@@ -0,0 +1,173 @@
+#!/usr/bin/env node
+// Test script for mixed-content message testing
+// Tests receiving a mix of text, json, table, image, audio, video, and binary data
+// from JavaScript serviceA to JavaScript serviceB using NATSBridge.js smartreceive
+//
+// This test demonstrates that any combination and any number of mixed content
+// can be sent and received correctly.
+
+const { smartreceive, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_mix_test";
+const NATS_URL = "nats.yiem.cc";
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] ${message}`);
+}
+
+// Receiver: Listen for messages and verify mixed content handling
+async function test_mix_receive() {
+    // Connect to NATS
+    const { connect } = require('nats');
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        log_trace(`Received message on ${msg.subject}`);
+        
+        // Use NATSBridge.smartreceive to handle the data
+        const result = await smartreceive(
+            msg,
+            {
+                maxRetries: 5,
+                baseDelay: 100,
+                maxDelay: 5000
+            }
+        );
+        
+        log_trace(`Received ${result.payloads.length} payloads`);
+        
+        // Result is an envelope dictionary with payloads field
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
+            log_trace(`\n=== Payload: ${dataname} (type: ${type}) ===`);
+            
+            // Handle different data types
+            if (type === "text") {
+                // Text data - should be a String
+                if (typeof data === 'string') {
+                    log_trace(`  Type: String`);
+                    log_trace(`  Length: ${data.length} characters`);
+                    
+                    // Display first 200 characters
+                    if (data.length > 200) {
+                        log_trace(`  First 200 chars: ${data.substring(0, 200)}...`);
+                    } else {
+                        log_trace(`  Content: ${data}`);
+                    }
+                    
+                    // Save to file
+                    const fs = require('fs');
+                    const output_path = `./received_${dataname}.txt`;
+                    fs.writeFileSync(output_path, data);
+                    log_trace(`  Saved to: ${output_path}`);
+                } else {
+                    log_trace(`  ERROR: Expected String, got ${typeof data}`);
+                }
+                
+            } else if (type === "dictionary") {
+                // Dictionary data - should be an object
+                if (typeof data === 'object' && data !== null && !Array.isArray(data)) {
+                    log_trace(`  Type: Object`);
+                    log_trace(`  Keys: ${Object.keys(data).join(', ')}`);
+                    
+                    // Display nested content
+                    for (const [key, value] of Object.entries(data)) {
+                        log_trace(`  ${key} => ${value}`);
+                    }
+                    
+                    // Save to JSON file
+                    const fs = require('fs');
+                    const output_path = `./received_${dataname}.json`;
+                    const json_str = JSON.stringify(data, null, 2);
+                    fs.writeFileSync(output_path, json_str);
+                    log_trace(`  Saved to: ${output_path}`);
+                } else {
+                    log_trace(`  ERROR: Expected Object, got ${typeof data}`);
+                }
+                
+            } else if (type === "table") {
+                // Table data - should be an array of objects (requires apache-arrow)
+                log_trace(`  Type: Array (requires apache-arrow for full deserialization)`);
+                if (Array.isArray(data)) {
+                    log_trace(`  Length: ${data.length} items`);
+                    log_trace(`  First item: ${JSON.stringify(data[0])}`);
+                } else {
+                    log_trace(`  ERROR: Expected Array, got ${typeof data}`);
+                }
+                
+            } else if (type === "image" || type === "audio" || type === "video" || type === "binary") {
+                // Binary data - should be Uint8Array
+                if (data instanceof Uint8Array || Array.isArray(data)) {
+                    log_trace(`  Type: Uint8Array (binary)`);
+                    log_trace(`  Size: ${data.length} bytes`);
+                    
+                    // Save to file
+                    const fs = require('fs');
+                    const output_path = `./received_${dataname}.bin`;
+                    fs.writeFileSync(output_path, Buffer.from(data));
+                    log_trace(`  Saved to: ${output_path}`);
+                } else {
+                    log_trace(`  ERROR: Expected Uint8Array, got ${typeof data}`);
+                }
+                
+            } else {
+                log_trace(`  ERROR: Unknown data type '${type}'`);
+            }
+        }
+        
+        // Summary
+        console.log("\n=== Verification Summary ===");
+        const text_count = result.payloads.filter(x => x.type === "text").length;
+        const dict_count = result.payloads.filter(x => x.type === "dictionary").length;
+        const table_count = result.payloads.filter(x => x.type === "table").length;
+        const image_count = result.payloads.filter(x => x.type === "image").length;
+        const audio_count = result.payloads.filter(x => x.type === "audio").length;
+        const video_count = result.payloads.filter(x => x.type === "video").length;
+        const binary_count = result.payloads.filter(x => x.type === "binary").length;
+        
+        log_trace(`Text payloads: ${text_count}`);
+        log_trace(`Dictionary payloads: ${dict_count}`);
+        log_trace(`Table payloads: ${table_count}`);
+        log_trace(`Image payloads: ${image_count}`);
+        log_trace(`Audio payloads: ${audio_count}`);
+        log_trace(`Video payloads: ${video_count}`);
+        log_trace(`Binary payloads: ${binary_count}`);
+        
+        // Print transport type info for each payload if available
+        console.log("\n=== Payload Details ===");
+        for (const { dataname, data, type } of result.payloads) {
+            if (["image", "audio", "video", "binary"].includes(type)) {
+                log_trace(`${dataname}: ${data.length} bytes (binary)`);
+            } else if (type === "table") {
+                log_trace(`${dataname}: ${data.length} items (Array)`);
+            } else if (type === "dictionary") {
+                log_trace(`${dataname}: ${JSON.stringify(data).length} bytes (Object)`);
+            } else if (type === "text") {
+                log_trace(`${dataname}: ${data.length} characters (String)`);
+            }
+        }
+    }
+    
+    // Keep listening for 2 minutes
+    setTimeout(() => {
+        nc.close();
+        process.exit(0);
+    }, 120000);
+}
+
+// Run the test
+console.log("Starting mixed-content transport test...");
+console.log("Note: This receiver will wait for messages from the sender.");
+console.log("Run test_js_to_js_mix_sender.js first to send test data.");
+
+// Run receiver
+console.log("\ntesting smartreceive for mixed content");
+test_mix_receive();
+
+console.log("\nTest completed.");

test/test_js_table_receiver.js

@@ -0,0 +1,87 @@
+#!/usr/bin/env node
+// Test script for Table transport testing
+// Tests receiving 1 large and 1 small Tables via direct and link transport
+// Uses NATSBridge.js smartreceive with "table" type
+//
+// Note: This test requires the apache-arrow library to deserialize table data.
+// The JavaScript implementation uses apache-arrow for Arrow IPC deserialization.
+
+const { smartreceive, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_table_test";
+const NATS_URL = "nats.yiem.cc";
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] ${message}`);
+}
+
+// Receiver: Listen for messages and verify Table handling
+async function test_table_receive() {
+    // Connect to NATS
+    const { connect } = require('nats');
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        log_trace(`Received message on ${msg.subject}`);
+        
+        // Use NATSBridge.smartreceive to handle the data
+        const result = await smartreceive(
+            msg,
+            {
+                maxRetries: 5,
+                baseDelay: 100,
+                maxDelay: 5000
+            }
+        );
+        
+        // Result is an envelope dictionary with payloads field
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
+            if (Array.isArray(data)) {
+                log_trace(`Received Table '${dataname}' of type ${type}`);
+                
+                // Display table contents
+                console.log(`  Dimensions: ${data.length} rows x ${data.length > 0 ? Object.keys(data[0]).length : 0} columns`);
+                console.log(`  Columns: ${data.length > 0 ? Object.keys(data[0]).join(', ') : ''}`);
+                
+                // Display first few rows
+                console.log(`  First 5 rows:`);
+                for (let i = 0; i < Math.min(5, data.length); i++) {
+                    console.log(`    Row ${i}: ${JSON.stringify(data[i])}`);
+                }
+                
+                // Save to JSON file
+                const fs = require('fs');
+                const output_path = `./received_${dataname}.json`;
+                const json_str = JSON.stringify(data, null, 2);
+                fs.writeFileSync(output_path, json_str);
+                log_trace(`Saved Table to ${output_path}`);
+            } else {
+                log_trace(`Received unexpected data type for '${dataname}': ${typeof data}`);
+            }
+        }
+    }
+    
+    // Keep listening for 10 seconds
+    setTimeout(() => {
+        nc.close();
+        process.exit(0);
+    }, 120000);
+}
+
+// Run the test
+console.log("Starting Table transport test...");
+console.log("Note: This receiver will wait for messages from the sender.");
+console.log("Run test_js_to_js_table_sender.js first to send test data.");
+
+// Run receiver
+console.log("testing smartreceive");
+test_table_receive();
+
+console.log("Test completed.");

test/test_js_table_sender.js

@@ -0,0 +1,165 @@
+#!/usr/bin/env node
+// Test script for Table transport testing
+// Tests sending 1 large and 1 small Tables via direct and link transport
+// Uses NATSBridge.js smartsend with "table" type
+//
+// Note: This test requires the apache-arrow library to serialize/deserialize table data.
+// The JavaScript implementation uses apache-arrow for Arrow IPC serialization.
+
+const { smartsend, uuid4, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_table_test";
+const NATS_URL = "nats.yiem.cc";
+const FILESERVER_URL = "http://192.168.88.104:8080";
+
+// Create correlation ID for tracing
+const correlation_id = uuid4();
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
+}
+
+// File upload handler for plik server
+async function plik_upload_handler(fileserver_url, dataname, data, correlation_id) {
+    log_trace(correlation_id, `Uploading ${dataname} to fileserver: ${fileserver_url}`);
+    
+    // Step 1: Get upload ID and token
+    const url_getUploadID = `${fileserver_url}/upload`;
+    const headers = {
+        "Content-Type": "application/json"
+    };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to get upload ID: ${response.status} ${response.statusText}`);
+    }
+    
+    const responseJson = await response.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+    
+    // Step 2: Upload file data
+    const url_upload = `${fileserver_url}/file/${uploadid}`;
+    
+    // Create multipart form data
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    response = await fetch(url_upload, {
+        method: "POST",
+        headers: {
+            "X-UploadToken": uploadtoken
+        },
+        body: formData
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to upload file: ${response.status} ${response.statusText}`);
+    }
+    
+    const fileResponseJson = await response.json();
+    const fileid = fileResponseJson.id;
+    
+    // Build the download URL
+    const url = `${fileserver_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    log_trace(correlation_id, `Uploaded to URL: ${url}`);
+    
+    return {
+        status: response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Sender: Send Tables via smartsend
+async function test_table_send() {
+    // Note: This test requires apache-arrow library to create Arrow IPC data.
+    // For now, we'll use a simple array of objects as table data.
+    // In production, you would use the apache-arrow library to create Arrow IPC data.
+    
+    // Create a small Table (will use direct transport)
+    const small_table = [
+        { id: 1, name: "Alice", score: 95 },
+        { id: 2, name: "Bob", score: 88 },
+        { id: 3, name: "Charlie", score: 92 }
+    ];
+    
+    // Create a large Table (will use link transport if > 1MB)
+    // Generate a larger dataset (~2MB to ensure link transport)
+    const large_table = [];
+    for (let i = 0; i < 50000; i++) {
+        large_table.push({
+            id: i,
+            message: `msg_${i}`,
+            sender: `sender_${i}`,
+            timestamp: new Date().toISOString(),
+            priority: Math.floor(Math.random() * 3) + 1
+        });
+    }
+    
+    // Test data 1: small Table
+    const data1 = { dataname: "small_table", data: small_table, type: "table" };
+    
+    // Test data 2: large Table
+    const data2 = { dataname: "large_table", data: large_table, type: "table" };
+    
+    // Use smartsend with table type
+    // For small Table: will use direct transport (Arrow IPC encoded)
+    // For large Table: will use link transport (uploaded to fileserver)
+    const { env, env_json_str } = await smartsend(
+        SUBJECT,
+        [data1, data2],
+        {
+            natsUrl: NATS_URL,
+            fileserverUrl: FILESERVER_URL,
+            fileserverUploadHandler: plik_upload_handler,
+            sizeThreshold: 1_000_000,
+            correlationId: correlation_id,
+            msgPurpose: "chat",
+            senderName: "table_sender",
+            receiverName: "",
+            receiverId: "",
+            replyTo: "",
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
+        }
+    );
+    
+    log_trace(`Sent message with ${env.payloads.length} payloads`);
+    
+    // Log transport type for each payload
+    for (let i = 0; i < env.payloads.length; i++) {
+        const payload = env.payloads[i];
+        log_trace(`Payload ${i + 1} ('${payload.dataname}'):`);
+        log_trace(`  Transport: ${payload.transport}`);
+        log_trace(`  Type: ${payload.type}`);
+        log_trace(`  Size: ${payload.size} bytes`);
+        log_trace(`  Encoding: ${payload.encoding}`);
+        
+        if (payload.transport === "link") {
+            log_trace(`  URL: ${payload.data}`);
+        }
+    }
+}
+
+// Run the test
+console.log("Starting Table transport test...");
+console.log(`Correlation ID: ${correlation_id}`);
+
+// Run sender
+console.log("start smartsend for tables");
+test_table_send();
+
+console.log("Test completed.");

test/test_js_text_receiver.js

@@ -0,0 +1,81 @@
+#!/usr/bin/env node
+// Test script for text transport testing
+// Tests receiving 1 large and 1 small text from JavaScript serviceA to JavaScript serviceB
+// Uses NATSBridge.js smartreceive with "text" type
+
+const { smartreceive, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_text_test";
+const NATS_URL = "nats.yiem.cc";
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] ${message}`);
+}
+
+// Receiver: Listen for messages and verify text handling
+async function test_text_receive() {
+    // Connect to NATS
+    const { connect } = require('nats');
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        log_trace(`Received message on ${msg.subject}`);
+        
+        // Use NATSBridge.smartreceive to handle the data
+        const result = await smartreceive(
+            msg,
+            {
+                maxRetries: 5,
+                baseDelay: 100,
+                maxDelay: 5000
+            }
+        );
+        
+        // Result is an envelope dictionary with payloads field
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
+            if (typeof data === 'string') {
+                log_trace(`Received text '${dataname}' of type ${type}`);
+                log_trace(`  Length: ${data.length} characters`);
+                
+                // Display first 100 characters
+                if (data.length > 100) {
+                    log_trace(`  First 100 characters: ${data.substring(0, 100)}...`);
+                } else {
+                    log_trace(`  Content: ${data}`);
+                }
+                
+                // Save to file
+                const fs = require('fs');
+                const output_path = `./received_${dataname}.txt`;
+                fs.writeFileSync(output_path, data);
+                log_trace(`Saved text to ${output_path}`);
+            } else {
+                log_trace(`Received unexpected data type for '${dataname}': ${typeof data}`);
+            }
+        }
+    }
+    
+    // Keep listening for 10 seconds
+    setTimeout(() => {
+        nc.close();
+        process.exit(0);
+    }, 120000);
+}
+
+// Run the test
+console.log("Starting text transport test...");
+console.log("Note: This receiver will wait for messages from the sender.");
+console.log("Run test_js_to_js_text_sender.js first to send test data.");
+
+// Run receiver
+console.log("testing smartreceive for text");
+test_text_receive();
+
+console.log("Test completed.");

test/test_js_text_sender.js

@@ -0,0 +1,141 @@
+#!/usr/bin/env node
+// Test script for text transport testing
+// Tests sending 1 large and 1 small text from JavaScript serviceA to JavaScript serviceB
+// Uses NATSBridge.js smartsend with "text" type
+
+const { smartsend, uuid4, log_trace } = require('./src/NATSBridge');
+
+// Configuration
+const SUBJECT = "/NATSBridge_text_test";
+const NATS_URL = "nats.yiem.cc";
+const FILESERVER_URL = "http://192.168.88.104:8080";
+
+// Create correlation ID for tracing
+const correlation_id = uuid4();
+
+// Helper: Log with correlation ID
+function log_trace(message) {
+    const timestamp = new Date().toISOString();
+    console.log(`[${timestamp}] [Correlation: ${correlation_id}] ${message}`);
+}
+
+// File upload handler for plik server
+async function plik_upload_handler(fileserver_url, dataname, data, correlation_id) {
+    // Get upload ID
+    const url_getUploadID = `${fileserver_url}/upload`;
+    const headers = {
+        "Content-Type": "application/json"
+    };
+    const body = JSON.stringify({ OneShot: true });
+    
+    let response = await fetch(url_getUploadID, {
+        method: "POST",
+        headers: headers,
+        body: body
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to get upload ID: ${response.status} ${response.statusText}`);
+    }
+    
+    const responseJson = await response.json();
+    const uploadid = responseJson.id;
+    const uploadtoken = responseJson.uploadToken;
+    
+    // Upload file
+    const formData = new FormData();
+    const blob = new Blob([data], { type: "application/octet-stream" });
+    formData.append("file", blob, dataname);
+    
+    response = await fetch(`${fileserver_url}/file/${uploadid}`, {
+        method: "POST",
+        headers: {
+            "X-UploadToken": uploadtoken
+        },
+        body: formData
+    });
+    
+    if (!response.ok) {
+        throw new Error(`Failed to upload file: ${response.status} ${response.statusText}`);
+    }
+    
+    const fileResponseJson = await response.json();
+    const fileid = fileResponseJson.id;
+    
+    const url = `${fileserver_url}/file/${uploadid}/${fileid}/${encodeURIComponent(dataname)}`;
+    
+    return {
+        status: response.status,
+        uploadid: uploadid,
+        fileid: fileid,
+        url: url
+    };
+}
+
+// Sender: Send text via smartsend
+async function test_text_send() {
+    // Create a small text (will use direct transport)
+    const small_text = "Hello, this is a small text message. Testing direct transport via NATS.";
+    
+    // Create a large text (will use link transport if > 1MB)
+    // Generate a larger text (~2MB to ensure link transport)
+    const large_text_lines = [];
+    for (let i = 0; i < 50000; i++) {
+        large_text_lines.push(`Line ${i}: This is a sample text line with some content to pad the size. `);
+    }
+    const large_text = large_text_lines.join("");
+    
+    // Test data 1: small text
+    const data1 = { dataname: "small_text", data: small_text, type: "text" };
+    
+    // Test data 2: large text
+    const data2 = { dataname: "large_text", data: large_text, type: "text" };
+    
+    // Use smartsend with text type
+    // For small text: will use direct transport (Base64 encoded UTF-8)
+    // For large text: will use link transport (uploaded to fileserver)
+    const { env, env_json_str } = await smartsend(
+        SUBJECT,
+        [data1, data2],
+        {
+            natsUrl: NATS_URL,
+            fileserverUrl: FILESERVER_URL,
+            fileserverUploadHandler: plik_upload_handler,
+            sizeThreshold: 1_000_000,
+            correlationId: correlation_id,
+            msgPurpose: "chat",
+            senderName: "text_sender",
+            receiverName: "",
+            receiverId: "",
+            replyTo: "",
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
+        }
+    );
+    
+    log_trace(`Sent message with ${env.payloads.length} payloads`);
+    
+    // Log transport type for each payload
+    for (let i = 0; i < env.payloads.length; i++) {
+        const payload = env.payloads[i];
+        log_trace(`Payload ${i + 1} ('${payload.dataname}'):`);
+        log_trace(`  Transport: ${payload.transport}`);
+        log_trace(`  Type: ${payload.type}`);
+        log_trace(`  Size: ${payload.size} bytes`);
+        log_trace(`  Encoding: ${payload.encoding}`);
+        
+        if (payload.transport === "link") {
+            log_trace(`  URL: ${payload.data}`);
+        }
+    }
+}
+
+// Run the test
+console.log("Starting text transport test...");
+console.log(`Correlation ID: ${correlation_id}`);
+
+// Run sender
+console.log("start smartsend for text");
+test_text_send();
+
+console.log("Test completed.");

test/test_julia_dict_receiver.jl

@@ -0,0 +1,82 @@
+#!/usr/bin/env julia
+# Test script for Dictionary transport testing
+# Tests receiving 1 large and 1 small Dictionaries via direct and link transport
+# Uses NATSBridge.jl smartreceive with "dictionary" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_dict_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test dictionary transfer                                  #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+
+# Receiver: Listen for messages and verify Dictionary handling
+function test_dict_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Use NATSBridge.smartreceive to handle the data
+        # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
+        result = NATSBridge.smartreceive(
+            msg;
+            max_retries = 5,
+            base_delay = 100,
+            max_delay = 5000
+        )
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for (dataname, data, data_type) in result["payloads"]
+            if isa(data, JSON.Object{String, Any})
+                log_trace("Received Dictionary '$dataname' of type $data_type")
+                
+                # Display dictionary contents
+                println("  Contents:")
+                for (key, value) in data
+                    println("    $key => $value")
+                end
+                
+                # Save to JSON file
+                output_path = "./received_$dataname.json"
+                json_str = JSON.json(data, 2)
+                write(output_path, json_str)
+                log_trace("Saved Dictionary to $output_path")
+            else
+                log_trace("Received unexpected data type for '$dataname': $(typeof(data))")
+            end
+        end
+    end
+    
+    # Keep listening for 10 seconds
+    sleep(120)  
+    NATS.drain(conn)
+end
+
+
+# Run the test
+println("Starting Dictionary transport test...")
+println("Note: This receiver will wait for messages from the sender.")
+println("Run test_julia_to_julia_dict_sender.jl first to send test data.")
+
+# Run receiver
+println("testing smartreceive")
+test_dict_receive()
+
+println("Test completed.")

test/test_julia_dict_sender.jl

@@ -0,0 +1,137 @@
+#!/usr/bin/env julia
+# Test script for Dictionary transport testing
+# Tests sending 1 large and 1 small Dictionaries via direct and link transport
+# Uses NATSBridge.jl smartsend with "dictionary" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_dict_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+# Create correlation ID for tracing
+correlation_id = string(uuid4())
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test dictionary transfer                                  #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] [Correlation: $correlation_id] $message")
+end
+
+
+# File upload handler for plik server
+function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+    # Get upload ID
+    url_getUploadID = "$fileserver_url/upload"
+    headers = ["Content-Type" => "application/json"]
+    body = """{ "OneShot" : true }"""
+    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
+    responseJson = JSON.parse(String(httpResponse.body))
+    uploadid = responseJson["id"]
+    uploadtoken = responseJson["uploadToken"]
+    
+    # Upload file
+    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
+    url_upload = "$fileserver_url/file/$uploadid"
+    headers = ["X-UploadToken" => uploadtoken]
+    
+    form = HTTP.Form(Dict("file" => file_multipart))
+    httpResponse = HTTP.post(url_upload, headers, form)
+    responseJson = JSON.parse(String(httpResponse.body))
+    
+    fileid = responseJson["id"]
+    url = "$fileserver_url/file/$uploadid/$fileid/$dataname"
+    
+    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
+end
+
+
+# Sender: Send Dictionaries via smartsend
+function test_dict_send()
+    # Create a small Dictionary (will use direct transport)
+    small_dict = Dict(
+        "name" => "Alice",
+        "age" => 30,
+        "scores" => [95, 88, 92],
+        "metadata" => Dict(
+            "height" => 155,
+            "weight" => 55
+        )
+    )
+    
+    # Create a large Dictionary (will use link transport if > 1MB)
+    # Generate a larger dataset (~2MB to ensure link transport)
+    large_dict = Dict(
+        "ids" => collect(1:50000),
+        "names" => ["User_$i" for i in 1:50000],
+        "scores" => rand(1:100, 50000),
+        "categories" => ["Category_$(rand(1:10))" for i in 1:50000],
+        "metadata" => Dict(
+            "source" => "test_generator",
+            "timestamp" => string(Dates.now())
+        )
+    )
+    
+    # Test data 1: small Dictionary
+    data1 = ("small_dict", small_dict, "dictionary")
+    
+    # Test data 2: large Dictionary
+    data2 = ("large_dict", large_dict, "dictionary")
+    
+    # Use smartsend with dictionary type
+    # For small Dictionary: will use direct transport (JSON encoded)
+    # For large Dictionary: will use link transport (uploaded to fileserver)
+    env, env_json_str = NATSBridge.smartsend(
+        SUBJECT,
+        [data1, data2];  # List of (dataname, data, type) tuples
+        broker_url = NATS_URL,
+        fileserver_url = FILESERVER_URL,
+        fileserver_upload_handler = plik_upload_handler,
+        size_threshold = 1_000_000,  # 1MB threshold
+        correlation_id = correlation_id,
+        msg_purpose = "chat",
+        sender_name = "dict_sender",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
+    )
+    
+    log_trace("Sent message with $(length(env.payloads)) payloads")
+    
+    # Log transport type for each payload
+    for (i, payload) in enumerate(env.payloads)
+        log_trace("Payload $i ('$payload.dataname'):")
+        log_trace("  Transport: $(payload.transport)")
+        log_trace("  Type: $(payload.payload_type)")
+        log_trace("  Size: $(payload.size) bytes")
+        log_trace("  Encoding: $(payload.encoding)")
+        
+        if payload.transport == "link"
+            log_trace("  URL: $(payload.data)")
+        end
+    end
+end
+
+
+# Run the test
+println("Starting Dictionary transport test...")
+println("Correlation ID: $correlation_id")
+
+# Run sender
+println("start smartsend for dictionaries")
+test_dict_send()
+
+println("Test completed.")

test/test_julia_file_receiver.jl

@@ -0,0 +1,84 @@
+#!/usr/bin/env julia
+# Test script for large payload testing using binary transport
+# Tests sending a large file (> 1MB) via smartsend with binary type
+# Updated to match NATSBridge.jl API
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+
+# workdir = 
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test file transfer                                        #
+# ------------------------------------------------------------------------------------------------ #
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+# Receiver: Listen for messages and verify large payload handling
+function test_large_binary_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Use NATSBridge.smartreceive to handle the data
+        # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
+        result = NATSBridge.smartreceive(
+            msg;
+            max_retries = 5,
+            base_delay = 100,
+            max_delay = 5000
+        )
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for (dataname, data, data_type) in result["payloads"]
+            # Check transport type from the envelope
+            # For link transport, data is the URL string
+            # For direct transport, data is the actual payload bytes
+            
+            if isa(data, Vector{UInt8})
+                file_size = length(data)
+                log_trace("Received $(file_size) bytes of binary data for '$dataname' of type $data_type")
+                
+                # Save received data to a test file
+                output_path = "./new_$dataname"
+                write(output_path, data)
+                log_trace("Saved received data to $output_path")
+            else
+                log_trace("Received $(file_size) bytes of binary data for '$dataname' of type $data_type")
+            end
+        end
+    end
+    
+    # Keep listening for 10 seconds
+    sleep(120)  
+    NATS.drain(conn)
+end
+
+
+# Run the test
+println("Starting large binary payload test...")
+
+# # Run sender first
+# println("start smartsend")
+# test_large_binary_send()
+
+# Run receiver
+println("testing smartreceive")
+test_large_binary_receive()
+
+println("Test completed.")

test/test_julia_file_sender.jl

@@ -0,0 +1,123 @@
+#!/usr/bin/env julia
+# Test script for large payload testing using binary transport
+# Tests sending a large file (> 1MB) via smartsend with binary type
+# Updated to match NATSBridge.jl API
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+
+# workdir = 
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+# Create correlation ID for tracing
+correlation_id = string(uuid4())
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test file transfer                                        #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] [Correlation: $correlation_id] $message")
+end
+
+# File upload handler for plik server
+function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+    # Get upload ID
+    url_getUploadID = "$fileserver_url/upload"
+    headers = ["Content-Type" => "application/json"]
+    body = """{ "OneShot" : true }"""
+    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
+    responseJson = JSON.parse(String(httpResponse.body))
+    uploadid = responseJson["id"]
+    uploadtoken = responseJson["uploadToken"]
+    
+    # Upload file
+    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
+    url_upload = "$fileserver_url/file/$uploadid"
+    headers = ["X-UploadToken" => uploadtoken]
+    
+    form = HTTP.Form(Dict("file" => file_multipart))
+    httpResponse = HTTP.post(url_upload, headers, form)
+    responseJson = JSON.parse(String(httpResponse.body))
+    
+    fileid = responseJson["id"]
+    url = "$fileserver_url/file/$uploadid/$fileid/$dataname"
+    
+    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
+end
+
+# Sender: Send large binary file via smartsend
+function test_large_binary_send()
+    # Read the large file as binary data
+    
+    # test data 1
+    file_path1 = "./testFile_large.zip"
+    file_data1 = read(file_path1)
+    filename1 = basename(file_path1)
+    data1 = (filename1, file_data1, "binary")
+
+    # test data 2
+    file_path2 = "./testFile_small.zip"
+    file_data2 = read(file_path2)
+    filename2 = basename(file_path2)
+    data2 = (filename2, file_data2, "binary")
+    
+    
+    
+    # Use smartsend with binary type - will automatically use link transport
+    # if file size exceeds the threshold (1MB by default)
+    # API: smartsend(subject, [(dataname, data, type), ...]; keywords...)
+    env, env_json_str = NATSBridge.smartsend(
+        SUBJECT,
+        [data1, data2];  # List of (dataname, data, type) tuples
+        broker_url = NATS_URL;
+        fileserver_url = FILESERVER_URL,
+        fileserver_upload_handler = plik_upload_handler,
+        size_threshold = 1_000_000,
+        correlation_id = correlation_id,
+        msg_purpose = "chat",
+        sender_name = "sender",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
+    )
+    
+    log_trace("Sent message with transport: $(env.payloads[1].transport)")
+    log_trace("Envelope type: $(env.payloads[1].payload_type)")
+    
+    # Check if link transport was used
+    if env.payloads[1].transport == "link"
+        log_trace("Using link transport - file uploaded to HTTP server")
+        log_trace("URL: $(env.payloads[1].data)")
+    else
+        log_trace("Using direct transport - payload sent via NATS")
+    end
+end
+
+# Run the test
+println("Starting large binary payload test...")
+println("Correlation ID: $correlation_id")
+
+# Run sender first
+println("start smartsend")
+test_large_binary_send()
+
+# Run receiver
+# println("testing smartreceive")
+# test_large_binary_receive()
+
+println("Test completed.")

test/test_julia_julia_data_transfer.jl

@@ -1,190 +0,0 @@
-#!/usr/bin/env julia
-# Test script for large payload testing using binary transport
-# Tests sending a large file (> 1MB) via smartsend with binary type
-
-using NATS, JSON, UUIDs, Dates
-
-# Include the bridge module
-include("../src/NATSBridge.jl")
-using .NATSBridge
-
-# Configuration
-const SUBJECT = "/large_binary_test"
-const NATS_URL = "nats.yiem.cc"
-const FILESERVER_URL = "http://192.168.88.104:8080"
-
-# Create correlation ID for tracing
-correlation_id = string(uuid4())
-
-
-# ------------------------------------------------------------------------------------------------ #
-#                                        test file transfer                                        #
-# ------------------------------------------------------------------------------------------------ #
-
-# File path for large binary payload test
-const FILE_PATH = "./testFile_small.zip"
-const filename = basename(FILE_PATH)
-
-# Helper: Log with correlation ID
-function log_trace(message)
-    timestamp = Dates.now()
-    println("[$timestamp] [Correlation: $correlation_id] $message")
-end
-
-# Sender: Send large binary file via smartsend
-function test_large_binary_send()
-    conn = NATS.connect(NATS_URL)
-    # Read the large file as binary data
-    log_trace("Reading large file: $FILE_PATH")
-    file_data = read(FILE_PATH)
-    
-    file_size = length(file_data)
-    log_trace("File size: $file_size bytes")
-    
-    # Use smartsend with binary type - will automatically use link transport
-    # if file size exceeds the threshold (1MB by default)
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        file_data,
-        "binary",
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL;
-        dataname=filename
-    )
-    
-    log_trace("Sent message with transport: $(env.transport)")
-    log_trace("Envelope type: $(env.type)")
-    
-    # Check if link transport was used
-    if env.transport == "link"
-        log_trace("Using link transport - file uploaded to HTTP server")
-        log_trace("URL: $(env.url)")
-    else
-        log_trace("Using direct transport - payload sent via NATS")
-    end
-    
-    NATS.drain(conn)
-end
-
-# Receiver: Listen for messages and verify large payload handling
-function test_large_binary_receive()
-  conn = NATS.connect(NATS_URL)
-  NATS.subscribe(conn, SUBJECT) do msg
-    log_trace("Received message on $(msg.subject)")
-    
-    # Use NATSBridge.smartreceive to handle the data
-    result = NATSBridge.smartreceive(msg)
-    # Check transport type
-    if result.envelope.transport == "direct"
-        log_trace("Received direct transport")
-    else
-        # For link transport, result.data is the URL
-        log_trace("Received link transport")
-    end
-              
-    # Verify the received data matches the original
-    if result.envelope.type == "binary"
-      if isa(result.data, Vector{UInt8})
-        file_size = length(result.data)
-        log_trace("Received $(file_size) bytes of binary data")
-        
-        # Save received data to a test file
-        println("metadata ", result.envelope.metadata)
-        dataname = result.envelope.metadata["dataname"]
-        if dataname != "NA"
-          output_path = "./new_$dataname"
-          write(output_path, result.data)
-          log_trace("Saved received data to $output_path")
-        end
-        
-        # Verify file size
-        original_size = length(read(FILE_PATH))
-        if file_size == result.envelope.metadata["content_length"]
-            log_trace("SUCCESS: File size matches! Original: $(result.envelope.metadata["content_length"]) bytes")
-        else
-            log_trace("WARNING: File size mismatch! Original: $(result.envelope.metadata["content_length"]), Received: $file_size")
-        end
-      end
-    end
-  end
-
-  # Keep listening for 10 seconds
-  sleep(120)  
-  NATS.drain(conn)
-end
-
-
-# Run the test
-println("Starting large binary payload test...")
-println("Correlation ID: $correlation_id")
-println("File: $FILE_PATH")
-
-# Run sender first
-println("start smartsend")
-test_large_binary_send()
-
-# # Run receiver
-# println("testing smartreceive")
-# test_large_binary_receive()
-
-println("Test completed.")
-
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test/test_julia_mix_payloads_receiver.jl

@@ -0,0 +1,228 @@
+#!/usr/bin/env julia
+# Test script for mixed-content message testing
+# Tests receiving a mix of text, json, table, image, audio, video, and binary data
+# from Julia serviceA to Julia serviceB using NATSBridge.jl smartreceive
+#
+# This test demonstrates that any combination and any number of mixed content
+# can be sent and received correctly.
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP, Base64
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_mix_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                      test mixed content transfer                                 #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+
+# Receiver: Listen for messages and verify mixed content handling
+function test_mix_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Use NATSBridge.smartreceive to handle the data
+        # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
+        result = NATSBridge.smartreceive(
+            msg;
+            max_retries = 5,
+            base_delay = 100,
+            max_delay = 5000
+        )
+        
+        log_trace("Received $(length(result["payloads"])) payloads")
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for (dataname, data, data_type) in result["payloads"]
+            log_trace("\n=== Payload: $dataname (type: $data_type) ===")
+            
+            # Handle different data types
+            if data_type == "text"
+                # Text data - should be a String
+                if isa(data, String)
+                    log_trace("  Type: String")
+                    log_trace("  Length: $(length(data)) characters")
+                    
+                    # Display first 200 characters
+                    if length(data) > 200
+                        log_trace("  First 200 chars: $(data[1:200])...")
+                    else
+                        log_trace("  Content: $data")
+                    end
+                    
+                    # Save to file
+                    output_path = "./received_$dataname.txt"
+                    write(output_path, data)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected String, got $(typeof(data))")
+                end
+                
+            elseif data_type == "dictionary"
+                # Dictionary data - should be JSON object
+                if isa(data, JSON.Object{String, Any})
+                    log_trace("  Type: Dict")
+                    log_trace("  Keys: $(keys(data))")
+                    
+                    # Display nested content
+                    for (key, value) in data
+                        log_trace("  $key => $value")
+                    end
+                    
+                    # Save to JSON file
+                    output_path = "./received_$dataname.json"
+                    json_str = JSON.json(data, 2)
+                    write(output_path, json_str)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected Dict, got $(typeof(data))")
+                end
+                
+            elseif data_type == "table"
+                # Table data - should be a DataFrame
+                data = DataFrame(data)
+                if isa(data, DataFrame)
+                    log_trace("  Type: DataFrame")
+                    log_trace("  Dimensions: $(size(data, 1)) rows x $(size(data, 2)) columns")
+                    log_trace("  Columns: $(names(data))")
+                    
+                    # Display first few rows
+                    log_trace("  First 5 rows:")
+                    display(data[1:min(5, size(data, 1)), :])
+                    
+                    # Save to Arrow file
+                    output_path = "./received_$dataname.arrow"
+                    io = IOBuffer()
+                    Arrow.write(io, data)
+                    write(output_path, take!(io))
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected DataFrame, got $(typeof(data))")
+                end
+                
+            elseif data_type == "image"
+                # Image data - should be Vector{UInt8}
+                if isa(data, Vector{UInt8})
+                    log_trace("  Type: Vector{UInt8} (binary)")
+                    log_trace("  Size: $(length(data)) bytes")
+                    
+                    # Save to file
+                    output_path = "./received_$dataname.bin"
+                    write(output_path, data)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected Vector{UInt8}, got $(typeof(data))")
+                end
+                
+            elseif data_type == "audio"
+                # Audio data - should be Vector{UInt8}
+                if isa(data, Vector{UInt8})
+                    log_trace("  Type: Vector{UInt8} (binary)")
+                    log_trace("  Size: $(length(data)) bytes")
+                    
+                    # Save to file
+                    output_path = "./received_$dataname.bin"
+                    write(output_path, data)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected Vector{UInt8}, got $(typeof(data))")
+                end
+                
+            elseif data_type == "video"
+                # Video data - should be Vector{UInt8}
+                if isa(data, Vector{UInt8})
+                    log_trace("  Type: Vector{UInt8} (binary)")
+                    log_trace("  Size: $(length(data)) bytes")
+                    
+                    # Save to file
+                    output_path = "./received_$dataname.bin"
+                    write(output_path, data)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected Vector{UInt8}, got $(typeof(data))")
+                end
+                
+            elseif data_type == "binary"
+                # Binary data - should be Vector{UInt8}
+                if isa(data, Vector{UInt8})
+                    log_trace("  Type: Vector{UInt8} (binary)")
+                    log_trace("  Size: $(length(data)) bytes")
+                    
+                    # Save to file
+                    output_path = "./received_$dataname.bin"
+                    write(output_path, data)
+                    log_trace("  Saved to: $output_path")
+                else
+                    log_trace("  ERROR: Expected Vector{UInt8}, got $(typeof(data))")
+                end
+                
+            else
+                log_trace("  ERROR: Unknown data type '$data_type'")
+            end
+        end
+        
+        # Summary
+        println("\n=== Verification Summary ===")
+        text_count = count(x -> x[3] == "text", result["payloads"])
+        dict_count = count(x -> x[3] == "dictionary", result["payloads"])
+        table_count = count(x -> x[3] == "table", result["payloads"])
+        image_count = count(x -> x[3] == "image", result["payloads"])
+        audio_count = count(x -> x[3] == "audio", result["payloads"])
+        video_count = count(x -> x[3] == "video", result["payloads"])
+        binary_count = count(x -> x[3] == "binary", result["payloads"])
+        
+        log_trace("Text payloads: $text_count")
+        log_trace("Dictionary payloads: $dict_count")
+        log_trace("Table payloads: $table_count")
+        log_trace("Image payloads: $image_count")
+        log_trace("Audio payloads: $audio_count")
+        log_trace("Video payloads: $video_count")
+        log_trace("Binary payloads: $binary_count")
+        
+        # Print transport type info for each payload if available
+        println("\n=== Payload Details ===")
+        for (dataname, data, data_type) in result["payloads"]
+            if data_type in ["image", "audio", "video", "binary"]
+                log_trace("$dataname: $(length(data)) bytes (binary)")
+            elseif data_type == "table"
+              data = DataFrame(data)
+                log_trace("$dataname: $(size(data, 1)) rows x $(size(data, 2)) columns (DataFrame)")
+            elseif data_type == "dictionary"
+                log_trace("$dataname: $(length(JSON.json(data))) bytes (Dict)")
+            elseif data_type == "text"
+                log_trace("$dataname: $(length(data)) characters (String)")
+            end
+        end
+    end
+    
+    # Keep listening for 2 minutes
+    sleep(120)  
+    NATS.drain(conn)
+end
+
+
+# Run the test
+println("Starting mixed-content transport test...")
+println("Note: This receiver will wait for messages from the sender.")
+println("Run test_julia_to_julia_mix_sender.jl first to send test data.")
+
+# Run receiver
+println("\ntesting smartreceive for mixed content")
+test_mix_receive()
+
+println("\nTest completed.")

test/test_julia_mix_payloads_sender.jl

@@ -0,0 +1,239 @@
+#!/usr/bin/env julia
+# Test script for mixed-content message testing
+# Tests sending a mix of text, json, table, image, audio, video, and binary data
+# from Julia serviceA to Julia serviceB using NATSBridge.jl smartsend
+# 
+# This test demonstrates that any combination and any number of mixed content
+# can be sent and received correctly.
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP, Base64
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_mix_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+# Create correlation ID for tracing
+correlation_id = string(uuid4())
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                      test mixed content transfer                                 #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] [Correlation: $correlation_id] $message")
+end
+
+
+# File upload handler for plik server
+function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+    # Get upload ID
+    url_getUploadID = "$fileserver_url/upload"
+    headers = ["Content-Type" => "application/json"]
+    body = """{ "OneShot" : true }"""
+    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
+    responseJson = JSON.parse(String(httpResponse.body))
+    uploadid = responseJson["id"]
+    uploadtoken = responseJson["uploadToken"]
+    
+    # Upload file
+    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
+    url_upload = "$fileserver_url/file/$uploadid"
+    headers = ["X-UploadToken" => uploadtoken]
+    
+    form = HTTP.Form(Dict("file" => file_multipart))
+    httpResponse = HTTP.post(url_upload, headers, form)
+    responseJson = JSON.parse(String(httpResponse.body))
+    
+    fileid = responseJson["id"]
+    url = "$fileserver_url/file/$uploadid/$fileid/$dataname"
+    
+    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
+end
+
+
+# Helper: Create sample data for each type
+function create_sample_data()
+    # Text data (small - direct transport)
+    text_data = "Hello! This is a test chat message. 🎉\nHow are you doing today? 😊"
+    
+    # Dictionary/JSON data (medium - could be direct or link)
+    dict_data = Dict(
+        "type" => "chat",
+        "sender" => "serviceA",
+        "receiver" => "serviceB",
+        "metadata" => Dict(
+            "timestamp" => string(Dates.now()),
+            "priority" => "high",
+            "tags" => ["urgent", "chat", "test"]
+        ),
+        "content" => Dict(
+            "text" => "This is a JSON-formatted chat message with nested structure.",
+            "format" => "markdown",
+            "mentions" => ["user1", "user2"]
+        )
+    )
+    
+    # Table data (DataFrame - small - direct transport)
+    table_data_small = DataFrame(
+        id = 1:10,
+        message = ["msg_$i" for i in 1:10],
+        sender = ["sender_$i" for i in 1:10],
+        timestamp = [string(Dates.now()) for _ in 1:10],
+        priority = rand(1:3, 10)
+    )
+    
+    # Table data (DataFrame - large - link transport)
+    # ~1.5MB of data (150,000 rows) - should trigger link transport
+    table_data_large = DataFrame(
+        id = 1:150_000,
+        message = ["msg_$i" for i in 1:150_000],
+        sender = ["sender_$i" for i in 1:150_000],
+        timestamp = [string(Dates.now()) for i in 1:150_000],
+        priority = rand(1:3, 150_000)
+    )
+    
+    # Image data (small binary - direct transport)
+    # Create a simple 10x10 pixel PNG-like data (128 bytes header + 100 pixels = 112 bytes)
+    # Using simple RGB data (10*10*3 = 300 bytes of pixel data)
+    image_width = 10
+    image_height = 10
+    image_data = UInt8[]
+    # PNG header (simplified)
+    push!(image_data, 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A)
+    # Simple RGB data (RGBRGBRGB...)
+    for i in 1:image_width*image_height
+        push!(image_data, 0xFF, 0x00, 0x00)  # Red pixel
+    end
+    
+    # Image data (large - link transport)
+    # Create a larger image (~1.5MB) to test link transport
+    large_image_width = 500
+    large_image_height = 1000
+    large_image_data = UInt8[]
+    # PNG header (simplified for 500x1000)
+    push!(large_image_data, 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A)
+    # RGB data (500*1000*3 = 1,500,000 bytes)
+    for i in 1:large_image_width*large_image_height
+        push!(large_image_data, rand(1:255), rand(1:255), rand(1:255))  # Random color pixels
+    end
+    
+    # Audio data (small binary - direct transport)
+    audio_data = UInt8[rand(1:255) for _ in 1:100]
+    
+    # Audio data (large - link transport)
+    # ~1.5MB of audio-like data
+    large_audio_data = UInt8[rand(1:255) for _ in 1:1_500_000]
+    
+    # Video data (small binary - direct transport)
+    video_data = UInt8[rand(1:255) for _ in 1:150]
+    
+    # Video data (large - link transport)
+    # ~1.5MB of video-like data
+    large_video_data = UInt8[rand(1:255) for _ in 1:1_500_000]
+    
+    # Binary data (small - direct transport)
+    binary_data = UInt8[rand(1:255) for _ in 1:200]
+    
+    # Binary data (large - link transport)
+    # ~1.5MB of binary data
+    large_binary_data = UInt8[rand(1:255) for _ in 1:1_500_000]
+    
+    return (
+        text_data,
+        dict_data,
+        table_data_small,
+        table_data_large,
+        image_data,
+        large_image_data,
+        audio_data,
+        large_audio_data,
+        video_data,
+        large_video_data,
+        binary_data,
+        large_binary_data
+    )
+end
+
+
+# Sender: Send mixed content via smartsend
+function test_mix_send()
+    # Create sample data
+    (text_data, dict_data, table_data_small, table_data_large, image_data, large_image_data, audio_data, large_audio_data, video_data, large_video_data, binary_data, large_binary_data) = create_sample_data()
+    
+    # Create payloads list - mixed content with both small and large data
+    # Small data uses direct transport, large data uses link transport
+    payloads = [
+        # Small data (direct transport) - text, dictionary, small table
+        ("chat_text", text_data, "text"),
+        ("chat_json", dict_data, "dictionary"),
+        ("chat_table_small", table_data_small, "table"),
+        
+        # Large data (link transport) - large table, large image, large audio, large video, large binary
+        ("chat_table_large", table_data_large, "table"),
+        ("user_image_large", large_image_data, "image"),
+        ("audio_clip_large", large_audio_data, "audio"),
+        ("video_clip_large", large_video_data, "video"),
+        ("binary_file_large", large_binary_data, "binary")
+    ]
+    
+    # Use smartsend with mixed content
+    env, env_json_str = NATSBridge.smartsend(
+        SUBJECT,
+        payloads;  # List of (dataname, data, type) tuples
+        broker_url = NATS_URL,
+        fileserver_url = FILESERVER_URL,
+        fileserver_upload_handler = plik_upload_handler,
+        size_threshold = 1_000_000,  # 1MB threshold
+        correlation_id = correlation_id,
+        msg_purpose = "chat",
+        sender_name = "mix_sender",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
+    )
+    
+    log_trace("Sent message with $(length(env.payloads)) payloads")
+    
+    # Log transport type for each payload
+    for (i, payload) in enumerate(env.payloads)
+        log_trace("Payload $i ('$payload.dataname'):")
+        log_trace("  Transport: $(payload.transport)")
+        log_trace("  Type: $(payload.payload_type)")
+        log_trace("  Size: $(payload.size) bytes")
+        log_trace("  Encoding: $(payload.encoding)")
+        
+        if payload.transport == "link"
+            log_trace("  URL: $(payload.data)")
+        end
+    end
+    
+    # Summary
+    println("\n--- Transport Summary ---")
+    direct_count = count(p -> p.transport == "direct", env.payloads)
+    link_count = count(p -> p.transport == "link", env.payloads)
+    log_trace("Direct transport: $direct_count payloads")
+    log_trace("Link transport: $link_count payloads")
+end
+
+
+# Run the test
+println("Starting mixed-content transport test...")
+println("Correlation ID: $correlation_id")
+
+# Run sender
+println("start smartsend for mixed content")
+test_mix_send()
+
+println("\nTest completed.")
+println("Note: Run test_julia_to_julia_mix_receiver.jl to receive the messages.")

test/test_julia_table_receiver.jl

@@ -0,0 +1,84 @@
+#!/usr/bin/env julia
+# Test script for DataFrame table transport testing
+# Tests receiving 1 large and 1 small DataFrames via direct and link transport
+# Uses NATSBridge.jl smartreceive with "table" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_table_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test table transfer                                       #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+
+# Receiver: Listen for messages and verify DataFrame table handling
+function test_table_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Use NATSBridge.smartreceive to handle the data
+        # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
+        result = NATSBridge.smartreceive(
+            msg;
+            max_retries = 5,
+            base_delay = 100,
+            max_delay = 5000
+        )
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for (dataname, data, data_type) in result["payloads"]
+          data = DataFrame(data)
+            if isa(data, DataFrame)
+                log_trace("Received DataFrame '$dataname' of type $data_type")
+                log_trace("  Dimensions: $(size(data, 1)) rows x $(size(data, 2)) columns")
+                log_trace("  Column names: $(names(data))")
+                
+                # Display first few rows
+                println("  First 5 rows:")
+                display(data[1:min(5, size(data, 1)), :])
+                
+                # Save to file
+                output_path = "./received_$dataname.arrow"
+                io = IOBuffer()
+                Arrow.write(io, data)
+                write(output_path, take!(io))
+                log_trace("Saved DataFrame to $output_path")
+            else
+                log_trace("Received unexpected data type for '$dataname': $(typeof(data))")
+            end
+        end
+    end
+    
+    # Keep listening for 10 seconds
+    sleep(120)  
+    NATS.drain(conn)
+end
+
+
+# Run the test
+println("Starting DataFrame table transport test...")
+println("Note: This receiver will wait for messages from the sender.")
+println("Run test_julia_to_julia_table_sender.jl first to send test data.")
+
+# Run receiver
+println("testing smartreceive")
+test_table_receive()
+
+println("Test completed.")

test/test_julia_table_sender.jl

@@ -0,0 +1,135 @@
+#!/usr/bin/env julia
+# Test script for DataFrame table transport testing
+# Tests sending 1 large and 1 small DataFrames via direct and link transport
+# Uses NATSBridge.jl smartsend with "table" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_table_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+# Create correlation ID for tracing
+correlation_id = string(uuid4())
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test table transfer                                       #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] [Correlation: $correlation_id] $message")
+end
+
+
+# File upload handler for plik server
+function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+    # Get upload ID
+    url_getUploadID = "$fileserver_url/upload"
+    headers = ["Content-Type" => "application/json"]
+    body = """{ "OneShot" : true }"""
+    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
+    responseJson = JSON.parse(String(httpResponse.body))
+    uploadid = responseJson["id"]
+    uploadtoken = responseJson["uploadToken"]
+    
+    # Upload file
+    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
+    url_upload = "$fileserver_url/file/$uploadid"
+    headers = ["X-UploadToken" => uploadtoken]
+    
+    form = HTTP.Form(Dict("file" => file_multipart))
+    httpResponse = HTTP.post(url_upload, headers, form)
+    responseJson = JSON.parse(String(httpResponse.body))
+    
+    fileid = responseJson["id"]
+    url = "$fileserver_url/file/$uploadid/$fileid/$dataname"
+    
+    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
+end
+
+
+# Sender: Send DataFrame tables via smartsend
+function test_table_send()
+    # Create a small DataFrame (will use direct transport)
+    small_df = DataFrame(
+        id = 1:10,
+        name = ["Alice", "Bob", "Charlie", "Diana", "Eve", "Frank", "Grace", "Henry", "Ivy", "Jack"],
+        score = [95, 88, 92, 85, 90, 78, 95, 88, 92, 85],
+        category = ["A", "B", "A", "B", "A", "B", "A", "B", "A", "B"]
+    )
+    
+    # Create a large DataFrame (will use link transport if > 1MB)
+    # Generate a larger dataset (~2MB to ensure link transport)
+    large_ids = 1:50000
+    large_names = ["User_$i" for i in 1:50000]
+    large_scores = rand(1:100, 50000)
+    large_categories = ["Category_$(rand(1:10))" for i in 1:50000]
+    
+    large_df = DataFrame(
+        id = large_ids,
+        name = large_names,
+        score = large_scores,
+        category = large_categories
+    )
+    
+    # Test data 1: small DataFrame
+    data1 = ("small_table", small_df, "table")
+    
+    # Test data 2: large DataFrame
+    data2 = ("large_table", large_df, "table")
+    
+    # Use smartsend with table type
+    # For small DataFrame: will use direct transport (Base64 encoded Arrow IPC)
+    # For large DataFrame: will use link transport (uploaded to fileserver)
+    env, env_json_str = NATSBridge.smartsend(
+        SUBJECT,
+        [data1, data2];  # List of (dataname, data, type) tuples
+        broker_url = NATS_URL,
+        fileserver_url = FILESERVER_URL,
+        fileserver_upload_handler = plik_upload_handler,
+        size_threshold = 1_000_000,  # 1MB threshold
+        correlation_id = correlation_id,
+        msg_purpose = "chat",
+        sender_name = "table_sender",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
+    )
+    
+    log_trace("Sent message with $(length(env.payloads)) payloads")
+    
+    # Log transport type for each payload
+    for (i, payload) in enumerate(env.payloads)
+        log_trace("Payload $i ('$payload.dataname'):")
+        log_trace("  Transport: $(payload.transport)")
+        log_trace("  Type: $(payload.payload_type)")
+        log_trace("  Size: $(payload.size) bytes")
+        log_trace("  Encoding: $(payload.encoding)")
+        
+        if payload.transport == "link"
+            log_trace("  URL: $(payload.data)")
+        end
+    end
+end
+
+
+# Run the test
+println("Starting DataFrame table transport test...")
+println("Correlation ID: $correlation_id")
+
+# Run sender
+println("start smartsend for tables")
+test_table_send()
+
+println("Test completed.")

test/test_julia_text_receiver.jl

@@ -0,0 +1,83 @@
+#!/usr/bin/env julia
+# Test script for text transport testing
+# Tests receiving 1 large and 1 small text from Julia serviceA to Julia serviceB
+# Uses NATSBridge.jl smartreceive with "text" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_text_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test text transfer                                        #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+
+# Receiver: Listen for messages and verify text handling
+function test_text_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Use NATSBridge.smartreceive to handle the data
+        # API: smartreceive(msg, download_handler; max_retries, base_delay, max_delay)
+        result = NATSBridge.smartreceive(
+            msg;
+            max_retries = 5,
+            base_delay = 100,
+            max_delay = 5000
+        )
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for (dataname, data, data_type) in result["payloads"]
+            if isa(data, String)
+                log_trace("Received text '$dataname' of type $data_type")
+                log_trace("  Length: $(length(data)) characters")
+                
+                # Display first 100 characters
+                if length(data) > 100
+                    log_trace("  First 100 characters: $(data[1:100])...")
+                else
+                    log_trace("  Content: $data")
+                end
+                
+                # Save to file
+                output_path = "./received_$dataname.txt"
+                write(output_path, data)
+                log_trace("Saved text to $output_path")
+            else
+                log_trace("Received unexpected data type for '$dataname': $(typeof(data))")
+            end
+        end
+    end
+    
+    # Keep listening for 10 seconds
+    sleep(120)  
+    NATS.drain(conn)
+end
+
+
+# Run the test
+println("Starting text transport test...")
+println("Note: This receiver will wait for messages from the sender.")
+println("Run test_julia_to_julia_text_sender.jl first to send test data.")
+
+# Run receiver
+println("testing smartreceive for text")
+test_text_receive()
+
+println("Test completed.")

test/test_julia_text_sender.jl

@@ -0,0 +1,120 @@
+#!/usr/bin/env julia
+# Test script for text transport testing
+# Tests sending 1 large and 1 small text from Julia serviceA to Julia serviceB
+# Uses NATSBridge.jl smartsend with "text" type
+
+using NATS, JSON, UUIDs, Dates, PrettyPrinting, DataFrames, Arrow, HTTP
+
+# Include the bridge module
+include("../src/NATSBridge.jl")
+using .NATSBridge
+
+# Configuration
+const SUBJECT = "/NATSBridge_text_test"
+const NATS_URL = "nats.yiem.cc"
+const FILESERVER_URL = "http://192.168.88.104:8080"
+
+# Create correlation ID for tracing
+correlation_id = string(uuid4())
+
+
+# ------------------------------------------------------------------------------------------------ #
+#                                        test text transfer                                        #
+# ------------------------------------------------------------------------------------------------ #
+
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] [Correlation: $correlation_id] $message")
+end
+
+
+# File upload handler for plik server
+function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+    # Get upload ID
+    url_getUploadID = "$fileserver_url/upload"
+    headers = ["Content-Type" => "application/json"]
+    body = """{ "OneShot" : true }"""
+    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
+    responseJson = JSON.parse(String(httpResponse.body))
+    uploadid = responseJson["id"]
+    uploadtoken = responseJson["uploadToken"]
+    
+    # Upload file
+    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
+    url_upload = "$fileserver_url/file/$uploadid"
+    headers = ["X-UploadToken" => uploadtoken]
+    
+    form = HTTP.Form(Dict("file" => file_multipart))
+    httpResponse = HTTP.post(url_upload, headers, form)
+    responseJson = JSON.parse(String(httpResponse.body))
+    
+    fileid = responseJson["id"]
+    url = "$fileserver_url/file/$uploadid/$fileid/$dataname"
+    
+    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
+end
+
+
+# Sender: Send text via smartsend
+function test_text_send()
+    # Create a small text (will use direct transport)
+    small_text = "Hello, this is a small text message. Testing direct transport via NATS."
+    
+    # Create a large text (will use link transport if > 1MB)
+    # Generate a larger text (~2MB to ensure link transport)
+    large_text = join(["Line $i: This is a sample text line with some content to pad the size. " for i in 1:50000], "")
+    
+    # Test data 1: small text
+    data1 = ("small_text", small_text, "text")
+    
+    # Test data 2: large text
+    data2 = ("large_text", large_text, "text")
+    
+    # Use smartsend with text type
+    # For small text: will use direct transport (Base64 encoded UTF-8)
+    # For large text: will use link transport (uploaded to fileserver)
+    env, env_json_str = NATSBridge.smartsend(
+        SUBJECT,
+        [data1, data2];  # List of (dataname, data, type) tuples
+        broker_url = NATS_URL,
+        fileserver_url = FILESERVER_URL,
+        fileserver_upload_handler = plik_upload_handler,
+        size_threshold = 1_000_000,  # 1MB threshold
+        correlation_id = correlation_id,
+        msg_purpose = "chat",
+        sender_name = "text_sender",
+        receiver_name = "",
+        receiver_id = "",
+        reply_to = "",
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
+    )
+    
+    log_trace("Sent message with $(length(env.payloads)) payloads")
+    
+    # Log transport type for each payload
+    for (i, payload) in enumerate(env.payloads)
+        log_trace("Payload $i ('$payload.dataname'):")
+        log_trace("  Transport: $(payload.transport)")
+        log_trace("  Type: $(payload.payload_type)")
+        log_trace("  Size: $(payload.size) bytes")
+        log_trace("  Encoding: $(payload.encoding)")
+        
+        if payload.transport == "link"
+            log_trace("  URL: $(payload.data)")
+        end
+    end
+end
+
+
+# Run the test
+println("Starting text transport test...")
+println("Correlation ID: $correlation_id")
+
+# Run sender
+println("start smartsend for text")
+test_text_send()
+
+println("Test completed.")

test/test_micropython_basic.py

@@ -0,0 +1,207 @@
+#!/usr/bin/env python3
+"""
+Basic functionality test for nats_bridge.py
+Tests the core classes and functions without NATS connection
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import (
+    MessagePayload,
+    MessageEnvelope,
+    smartsend,
+    smartreceive,
+    log_trace,
+    generate_uuid,
+    get_timestamp,
+    _serialize_data,
+    _deserialize_data
+)
+import json
+
+
+def test_message_payload():
+    """Test MessagePayload class"""
+    print("\n=== Testing MessagePayload ===")
+    
+    # Test direct transport with text
+    payload1 = MessagePayload(
+        data="Hello World",
+        msg_type="text",
+        id="test-id-1",
+        dataname="message",
+        transport="direct",
+        encoding="base64",
+        size=11
+    )
+    
+    assert payload1.id == "test-id-1"
+    assert payload1.dataname == "message"
+    assert payload1.type == "text"
+    assert payload1.transport == "direct"
+    assert payload1.encoding == "base64"
+    assert payload1.size == 11
+    print("  [PASS] MessagePayload with text data")
+    
+    # Test link transport with URL
+    payload2 = MessagePayload(
+        data="http://example.com/file.txt",
+        msg_type="binary",
+        id="test-id-2",
+        dataname="file",
+        transport="link",
+        encoding="none",
+        size=1000
+    )
+    
+    assert payload2.transport == "link"
+    assert payload2.data == "http://example.com/file.txt"
+    print("  [PASS] MessagePayload with link transport")
+    
+    # Test to_dict method
+    payload_dict = payload1.to_dict()
+    assert "id" in payload_dict
+    assert "dataname" in payload_dict
+    assert "type" in payload_dict
+    assert "transport" in payload_dict
+    assert "data" in payload_dict
+    print("  [PASS] MessagePayload.to_dict() method")
+
+
+def test_message_envelope():
+    """Test MessageEnvelope class"""
+    print("\n=== Testing MessageEnvelope ===")
+    
+    # Create payloads
+    payload1 = MessagePayload("Hello", "text", id="p1", dataname="msg1")
+    payload2 = MessagePayload("http://example.com/file", "binary", id="p2", dataname="file", transport="link")
+    
+    # Create envelope
+    env = MessageEnvelope(
+        send_to="/test/subject",
+        payloads=[payload1, payload2],
+        correlation_id="test-correlation-id",
+        msg_id="test-msg-id",
+        msg_purpose="chat",
+        sender_name="test_sender",
+        receiver_name="test_receiver",
+        reply_to="/test/reply"
+    )
+    
+    assert env.send_to == "/test/subject"
+    assert env.correlation_id == "test-correlation-id"
+    assert env.msg_id == "test-msg-id"
+    assert env.msg_purpose == "chat"
+    assert len(env.payloads) == 2
+    print("  [PASS] MessageEnvelope creation")
+    
+    # Test to_json method
+    json_str = env.to_json()
+    json_data = json.loads(json_str)
+    assert json_data["sendTo"] == "/test/subject"
+    assert json_data["correlationId"] == "test-correlation-id"
+    assert json_data["msgPurpose"] == "chat"
+    assert len(json_data["payloads"]) == 2
+    print("  [PASS] MessageEnvelope.to_json() method")
+
+
+def test_serialize_data():
+    """Test _serialize_data function"""
+    print("\n=== Testing _serialize_data ===")
+    
+    # Test text serialization
+    text_bytes = _serialize_data("Hello", "text")
+    assert isinstance(text_bytes, bytes)
+    assert text_bytes == b"Hello"
+    print("  [PASS] Text serialization")
+    
+    # Test dictionary serialization
+    dict_data = {"key": "value", "number": 42}
+    dict_bytes = _serialize_data(dict_data, "dictionary")
+    assert isinstance(dict_bytes, bytes)
+    parsed = json.loads(dict_bytes.decode('utf-8'))
+    assert parsed["key"] == "value"
+    print("  [PASS] Dictionary serialization")
+    
+    # Test binary serialization
+    binary_data = b"\x00\x01\x02"
+    binary_bytes = _serialize_data(binary_data, "binary")
+    assert binary_bytes == b"\x00\x01\x02"
+    print("  [PASS] Binary serialization")
+    
+    # Test image serialization
+    image_data = bytes([1, 2, 3, 4, 5])
+    image_bytes = _serialize_data(image_data, "image")
+    assert image_bytes == image_data
+    print("  [PASS] Image serialization")
+
+
+def test_deserialize_data():
+    """Test _deserialize_data function"""
+    print("\n=== Testing _deserialize_data ===")
+    
+    # Test text deserialization
+    text_bytes = b"Hello"
+    text_data = _deserialize_data(text_bytes, "text", "test-correlation-id")
+    assert text_data == "Hello"
+    print("  [PASS] Text deserialization")
+    
+    # Test dictionary deserialization
+    dict_bytes = b'{"key": "value"}'
+    dict_data = _deserialize_data(dict_bytes, "dictionary", "test-correlation-id")
+    assert dict_data == {"key": "value"}
+    print("  [PASS] Dictionary deserialization")
+    
+    # Test binary deserialization
+    binary_data = b"\x00\x01\x02"
+    binary_result = _deserialize_data(binary_data, "binary", "test-correlation-id")
+    assert binary_result == b"\x00\x01\x02"
+    print("  [PASS] Binary deserialization")
+
+
+def test_utilities():
+    """Test utility functions"""
+    print("\n=== Testing Utility Functions ===")
+    
+    # Test generate_uuid
+    uuid1 = generate_uuid()
+    uuid2 = generate_uuid()
+    assert uuid1 != uuid2
+    print(f"  [PASS] generate_uuid() - generated: {uuid1}")
+    
+    # Test get_timestamp
+    timestamp = get_timestamp()
+    assert "T" in timestamp
+    print(f"  [PASS] get_timestamp() - generated: {timestamp}")
+
+
+def main():
+    """Run all tests"""
+    print("=" * 60)
+    print("NATSBridge Python/Micropython - Basic Functionality Tests")
+    print("=" * 60)
+    
+    try:
+        test_message_payload()
+        test_message_envelope()
+        test_serialize_data()
+        test_deserialize_data()
+        test_utilities()
+        
+        print("\n" + "=" * 60)
+        print("ALL TESTS PASSED!")
+        print("=" * 60)
+        
+    except Exception as e:
+        print(f"\n[FAIL] Test failed with error: {e}")
+        import traceback
+        traceback.print_exc()
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()

test/test_micropython_dict_receiver.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+"""
+Test script for dictionary transport testing - Receiver
+Tests receiving dictionary messages via NATS using nats_bridge.py smartreceive
+"""
+
+import sys
+import os
+import json
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartreceive, log_trace
+import nats
+import asyncio
+
+# Configuration
+SUBJECT = "/NATSBridge_dict_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+
+
+async def main():
+    log_trace("", f"Starting dictionary transport receiver test...")
+    log_trace("", f"Note: This receiver will wait for messages from the sender.")
+    log_trace("", f"Run test_micropython_dict_sender.py first to send test data.")
+    
+    # Connect to NATS
+    nc = await nats.connect(NATS_URL)
+    log_trace("", f"Connected to NATS at {NATS_URL}")
+    
+    # Subscribe to the subject
+    async def message_handler(msg):
+        log_trace("", f"Received message on {msg.subject}")
+        
+        # Use smartreceive to handle the data
+        result = smartreceive(msg.data)
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for dataname, data, data_type in result["payloads"]:
+            if isinstance(data, dict):
+                log_trace(result.get("correlationId", ""), f"Received dictionary '{dataname}' of type {data_type}")
+                log_trace(result.get("correlationId", ""), f"  Keys: {list(data.keys())}")
+                
+                # Display first few items for small dicts
+                if isinstance(data, dict) and len(data) <= 10:
+                    log_trace(result.get("correlationId", ""), f"  Content: {json.dumps(data, indent=2)}")
+                else:
+                    # For large dicts, show summary
+                    log_trace(result.get("correlationId", ""), f"  Summary: {json.dumps(data, default=str)[:200]}...")
+                
+                # Save to file
+                output_path = f"./received_{dataname}.json"
+                with open(output_path, 'w') as f:
+                    json.dump(data, f, indent=2)
+                log_trace(result.get("correlationId", ""), f"Saved dictionary to {output_path}")
+            else:
+                log_trace(result.get("correlationId", ""), f"Received unexpected data type for '{dataname}': {type(data)}")
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    log_trace("", f"Subscribed to {SUBJECT} with subscription ID: {sid}")
+    
+    # Keep listening for 120 seconds
+    await asyncio.sleep(120)
+    await nc.close()
+    log_trace("", "Test completed.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

test/test_micropython_dict_sender.py

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+"""
+Test script for dictionary transport testing - Micropython
+Tests sending dictionary messages via NATS using nats_bridge.py smartsend
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartsend, log_trace
+import uuid
+
+# Configuration
+SUBJECT = "/NATSBridge_dict_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+FILESERVER_URL = "http://192.168.88.104:8080"
+SIZE_THRESHOLD = 1_000_000  # 1MB
+
+# Create correlation ID for tracing
+correlation_id = str(uuid.uuid4())
+
+
+def main():
+    # Create a small dictionary (will use direct transport)
+    small_dict = {
+        "name": "test",
+        "value": 42,
+        "enabled": True,
+        "metadata": {
+            "version": "1.0.0",
+            "timestamp": "2026-02-22T12:00:00Z"
+        }
+    }
+    
+    # Create a large dictionary (will use link transport if > 1MB)
+    # Generate a larger dictionary (~2MB to ensure link transport)
+    large_dict = {
+        "id": str(uuid.uuid4()),
+        "items": [
+            {
+                "index": i,
+                "name": f"item_{i}",
+                "value": i * 1.5,
+                "data": "x" * 10000  # Large string per item
+            }
+            for i in range(200)
+        ],
+        "metadata": {
+            "count": 200,
+            "created": "2026-02-22T12:00:00Z"
+        }
+    }
+    
+    # Test data 1: small dictionary
+    data1 = ("small_dict", small_dict, "dictionary")
+    
+    # Test data 2: large dictionary
+    data2 = ("large_dict", large_dict, "dictionary")
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {SUBJECT}")
+    log_trace(correlation_id, f"Correlation ID: {correlation_id}")
+    
+    # Use smartsend with dictionary type
+    env, env_json_str = smartsend(
+        SUBJECT,
+        [data1, data2],  # List of (dataname, data, type) tuples
+        nats_url=NATS_URL,
+        fileserver_url=FILESERVER_URL,
+        size_threshold=SIZE_THRESHOLD,
+        correlation_id=correlation_id,
+        msg_purpose="chat",
+        sender_name="dict_sender",
+        receiver_name="",
+        receiver_id="",
+        reply_to="",
+        reply_to_msg_id="",
+        is_publish=True  # Publish the message to NATS
+    )
+    
+    log_trace(correlation_id, f"Sent message with {len(env.payloads)} payloads")
+    
+    # Log transport type for each payload
+    for i, payload in enumerate(env.payloads):
+        log_trace(correlation_id, f"Payload {i+1} ('{payload.dataname}'):")
+        log_trace(correlation_id, f"  Transport: {payload.transport}")
+        log_trace(correlation_id, f"  Type: {payload.type}")
+        log_trace(correlation_id, f"  Size: {payload.size} bytes")
+        log_trace(correlation_id, f"  Encoding: {payload.encoding}")
+        
+        if payload.transport == "link":
+            log_trace(correlation_id, f"  URL: {payload.data}")
+    
+    print(f"Test completed. Correlation ID: {correlation_id}")
+
+
+if __name__ == "__main__":
+    main()

test/test_micropython_file_receiver.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""
+Test script for file transport testing - Receiver
+Tests receiving binary files via NATS using nats_bridge.py smartreceive
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartreceive, log_trace
+import nats
+import asyncio
+
+# Configuration
+SUBJECT = "/NATSBridge_file_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+
+
+async def main():
+    log_trace("", f"Starting file transport receiver test...")
+    log_trace("", f"Note: This receiver will wait for messages from the sender.")
+    log_trace("", f"Run test_micropython_file_sender.py first to send test data.")
+    
+    # Connect to NATS
+    nc = await nats.connect(NATS_URL)
+    log_trace("", f"Connected to NATS at {NATS_URL}")
+    
+    # Subscribe to the subject
+    async def message_handler(msg):
+        log_trace("", f"Received message on {msg.subject}")
+        
+        # Use smartreceive to handle the data
+        result = smartreceive(msg.data)
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for dataname, data, data_type in result["payloads"]:
+            if isinstance(data, bytes):
+                log_trace(result.get("correlationId", ""), f"Received binary '{dataname}' of type {data_type}")
+                log_trace(result.get("correlationId", ""), f"  Size: {len(data)} bytes")
+                
+                # Display first 100 bytes as hex
+                log_trace(result.get("correlationId", ""), f"  First 100 bytes (hex): {data[:100].hex()}")
+                
+                # Save to file
+                output_path = f"./received_{dataname}.bin"
+                with open(output_path, 'wb') as f:
+                    f.write(data)
+                log_trace(result.get("correlationId", ""), f"Saved binary to {output_path}")
+            else:
+                log_trace(result.get("correlationId", ""), f"Received unexpected data type for '{dataname}': {type(data)}")
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    log_trace("", f"Subscribed to {SUBJECT} with subscription ID: {sid}")
+    
+    # Keep listening for 120 seconds
+    await asyncio.sleep(120)
+    await nc.close()
+    log_trace("", "Test completed.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

test/test_micropython_file_sender.py

@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""
+Test script for file transport testing - Micropython
+Tests sending binary files via NATS using nats_bridge.py smartsend
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartsend, log_trace
+import uuid
+
+# Configuration
+SUBJECT = "/NATSBridge_file_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+FILESERVER_URL = "http://192.168.88.104:8080"
+SIZE_THRESHOLD = 1_000_000  # 1MB
+
+# Create correlation ID for tracing
+correlation_id = str(uuid.uuid4())
+
+
+def main():
+    # Create small binary data (will use direct transport)
+    small_binary = b"This is small binary data for testing direct transport."
+    small_binary += b"\x00" * 100  # Add some null bytes
+    
+    # Create large binary data (will use link transport if > 1MB)
+    # Generate a larger binary (~2MB to ensure link transport)
+    large_binary = bytes([
+        (i * 7) % 256 for i in range(2_000_000)
+    ])
+    
+    # Test data 1: small binary (direct transport)
+    data1 = ("small_binary", small_binary, "binary")
+    
+    # Test data 2: large binary (link transport)
+    data2 = ("large_binary", large_binary, "binary")
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {SUBJECT}")
+    log_trace(correlation_id, f"Correlation ID: {correlation_id}")
+    
+    # Use smartsend with binary type
+    env, env_json_str = smartsend(
+        SUBJECT,
+        [data1, data2],  # List of (dataname, data, type) tuples
+        nats_url=NATS_URL,
+        fileserver_url=FILESERVER_URL,
+        size_threshold=SIZE_THRESHOLD,
+        correlation_id=correlation_id,
+        msg_purpose="chat",
+        sender_name="file_sender",
+        receiver_name="",
+        receiver_id="",
+        reply_to="",
+        reply_to_msg_id="",
+        is_publish=True  # Publish the message to NATS
+    )
+    
+    log_trace(correlation_id, f"Sent message with {len(env.payloads)} payloads")
+    
+    # Log transport type for each payload
+    for i, payload in enumerate(env.payloads):
+        log_trace(correlation_id, f"Payload {i+1} ('{payload.dataname}'):")
+        log_trace(correlation_id, f"  Transport: {payload.transport}")
+        log_trace(correlation_id, f"  Type: {payload.type}")
+        log_trace(correlation_id, f"  Size: {payload.size} bytes")
+        log_trace(correlation_id, f"  Encoding: {payload.encoding}")
+        
+        if payload.transport == "link":
+            log_trace(correlation_id, f"  URL: {payload.data}")
+    
+    print(f"Test completed. Correlation ID: {correlation_id}")
+
+
+if __name__ == "__main__":
+    main()

test/test_micropython_mixed_receiver.py

@@ -0,0 +1,97 @@
+#!/usr/bin/env python3
+"""
+Test script for mixed payload testing - Receiver
+Tests receiving mixed payload types via NATS using nats_bridge.py smartreceive
+"""
+
+import sys
+import os
+import json
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartreceive, log_trace
+import nats
+import asyncio
+
+# Configuration
+SUBJECT = "/NATSBridge_mixed_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+
+
+async def main():
+    log_trace("", f"Starting mixed payload receiver test...")
+    log_trace("", f"Note: This receiver will wait for messages from the sender.")
+    log_trace("", f"Run test_micropython_mixed_sender.py first to send test data.")
+    
+    # Connect to NATS
+    nc = await nats.connect(NATS_URL)
+    log_trace("", f"Connected to NATS at {NATS_URL}")
+    
+    # Subscribe to the subject
+    async def message_handler(msg):
+        log_trace("", f"Received message on {msg.subject}")
+        
+        # Use smartreceive to handle the data
+        result = smartreceive(msg.data)
+        
+        log_trace(result.get("correlationId", ""), f"Received envelope with {len(result['payloads'])} payloads")
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for dataname, data, data_type in result["payloads"]:
+            log_trace(result.get("correlationId", ""), f"\n--- Payload: {dataname} (type: {data_type}) ---")
+            
+            if isinstance(data, str):
+                log_trace(result.get("correlationId", ""), f"  Type: text/string")
+                log_trace(result.get("correlationId", ""), f"  Length: {len(data)} characters")
+                if len(data) <= 100:
+                    log_trace(result.get("correlationId", ""), f"  Content: {data}")
+                else:
+                    log_trace(result.get("correlationId", ""), f"  First 100 chars: {data[:100]}...")
+                # Save to file
+                output_path = f"./received_{dataname}.txt"
+                with open(output_path, 'w') as f:
+                    f.write(data)
+                log_trace(result.get("correlationId", ""), f"  Saved to: {output_path}")
+                
+            elif isinstance(data, dict):
+                log_trace(result.get("correlationId", ""), f"  Type: dictionary")
+                log_trace(result.get("correlationId", ""), f"  Keys: {list(data.keys())}")
+                log_trace(result.get("correlationId", ""), f"  Content: {json.dumps(data, indent=2)}")
+                # Save to file
+                output_path = f"./received_{dataname}.json"
+                with open(output_path, 'w') as f:
+                    json.dump(data, f, indent=2)
+                log_trace(result.get("correlationId", ""), f"  Saved to: {output_path}")
+                
+            elif isinstance(data, bytes):
+                log_trace(result.get("correlationId", ""), f"  Type: binary")
+                log_trace(result.get("correlationId", ""), f"  Size: {len(data)} bytes")
+                log_trace(result.get("correlationId", ""), f"  First 100 bytes (hex): {data[:100].hex()}")
+                # Save to file
+                output_path = f"./received_{dataname}.bin"
+                with open(output_path, 'wb') as f:
+                    f.write(data)
+                log_trace(result.get("correlationId", ""), f"  Saved to: {output_path}")
+            else:
+                log_trace(result.get("correlationId", ""), f"  Received unexpected data type: {type(data)}")
+        
+        # Log envelope metadata
+        log_trace(result.get("correlationId", ""), f"\n--- Envelope Metadata ---")
+        log_trace(result.get("correlationId", ""), f"  Correlation ID: {result.get('correlationId', 'N/A')}")
+        log_trace(result.get("correlationId", ""), f"  Message ID: {result.get('msgId', 'N/A')}")
+        log_trace(result.get("correlationId", ""), f"  Sender: {result.get('senderName', 'N/A')}")
+        log_trace(result.get("correlationId", ""), f"  Purpose: {result.get('msgPurpose', 'N/A')}")
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    log_trace("", f"Subscribed to {SUBJECT} with subscription ID: {sid}")
+    
+    # Keep listening for 120 seconds
+    await asyncio.sleep(120)
+    await nc.close()
+    log_trace("", "Test completed.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

test/test_micropython_mixed_sender.py

@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+"""
+Test script for mixed payload testing - Micropython
+Tests sending mixed payload types via NATS using nats_bridge.py smartsend
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartsend, log_trace
+import uuid
+
+# Configuration
+SUBJECT = "/NATSBridge_mixed_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+FILESERVER_URL = "http://192.168.88.104:8080"
+SIZE_THRESHOLD = 1_000_000  # 1MB
+
+# Create correlation ID for tracing
+correlation_id = str(uuid.uuid4())
+
+
+def main():
+    # Create payloads for mixed content test
+    
+    # 1. Small text (direct transport)
+    text_data = "Hello, this is a text message for testing mixed payloads!"
+    
+    # 2. Small dictionary (direct transport)
+    dict_data = {
+        "status": "ok",
+        "code": 200,
+        "message": "Test successful",
+        "items": [1, 2, 3]
+    }
+    
+    # 3. Small binary (direct transport)
+    binary_data = b"\x00\x01\x02\x03\x04\x05" + b"\xff" * 100
+    
+    # 4. Large text (link transport - will use fileserver)
+    large_text = "\n".join([
+        f"Line {i}: This is a large text payload for link transport testing. " * 50
+        for i in range(100)
+    ])
+    
+    # Test data list - mixed payload types
+    data = [
+        ("message_text", text_data, "text"),
+        ("config_dict", dict_data, "dictionary"),
+        ("small_binary", binary_data, "binary"),
+        ("large_text", large_text, "text"),
+    ]
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {SUBJECT}")
+    log_trace(correlation_id, f"Correlation ID: {correlation_id}")
+    
+    # Use smartsend with mixed types
+    env, env_json_str = smartsend(
+        SUBJECT,
+        data,  # List of (dataname, data, type) tuples
+        nats_url=NATS_URL,
+        fileserver_url=FILESERVER_URL,
+        size_threshold=SIZE_THRESHOLD,
+        correlation_id=correlation_id,
+        msg_purpose="chat",
+        sender_name="mixed_sender",
+        receiver_name="",
+        receiver_id="",
+        reply_to="",
+        reply_to_msg_id="",
+        is_publish=True  # Publish the message to NATS
+    )
+    
+    log_trace(correlation_id, f"Sent message with {len(env.payloads)} payloads")
+    
+    # Log transport type for each payload
+    for i, payload in enumerate(env.payloads):
+        log_trace(correlation_id, f"Payload {i+1} ('{payload.dataname}'):")
+        log_trace(correlation_id, f"  Transport: {payload.transport}")
+        log_trace(correlation_id, f"  Type: {payload.type}")
+        log_trace(correlation_id, f"  Size: {payload.size} bytes")
+        log_trace(correlation_id, f"  Encoding: {payload.encoding}")
+        
+        if payload.transport == "link":
+            log_trace(correlation_id, f"  URL: {payload.data}")
+    
+    print(f"Test completed. Correlation ID: {correlation_id}")
+
+
+if __name__ == "__main__":
+    main()

test/test_micropython_text_receiver.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python3
+"""
+Test script for text transport testing - Receiver
+Tests receiving text messages via NATS using nats_bridge.py smartreceive
+"""
+
+import sys
+import os
+import json
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartreceive, log_trace
+import nats
+import asyncio
+
+# Configuration
+SUBJECT = "/NATSBridge_text_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+
+
+async def main():
+    log_trace("", f"Starting text transport receiver test...")
+    log_trace("", f"Note: This receiver will wait for messages from the sender.")
+    log_trace("", f"Run test_micropython_text_sender.py first to send test data.")
+    
+    # Connect to NATS
+    nc = await nats.connect(NATS_URL)
+    log_trace("", f"Connected to NATS at {NATS_URL}")
+    
+    # Subscribe to the subject
+    async def message_handler(msg):
+        log_trace("", f"Received message on {msg.subject}")
+        
+        # Use smartreceive to handle the data
+        result = smartreceive(msg.data)
+        
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
+        for dataname, data, data_type in result["payloads"]:
+            if isinstance(data, str):
+                log_trace(result.get("correlationId", ""), f"Received text '{dataname}' of type {data_type}")
+                log_trace(result.get("correlationId", ""), f"  Length: {len(data)} characters")
+                
+                # Display first 100 characters
+                if len(data) > 100:
+                    log_trace(result.get("correlationId", ""), f"  First 100 characters: {data[:100]}...")
+                else:
+                    log_trace(result.get("correlationId", ""), f"  Content: {data}")
+                
+                # Save to file
+                output_path = f"./received_{dataname}.txt"
+                with open(output_path, 'w') as f:
+                    f.write(data)
+                log_trace(result.get("correlationId", ""), f"Saved text to {output_path}")
+            else:
+                log_trace(result.get("correlationId", ""), f"Received unexpected data type for '{dataname}': {type(data)}")
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    log_trace("", f"Subscribed to {SUBJECT} with subscription ID: {sid}")
+    
+    # Keep listening for 120 seconds
+    await asyncio.sleep(120)
+    await nc.close()
+    log_trace("", "Test completed.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

test/test_micropython_text_sender.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+"""
+Test script for text transport testing - Micropython
+Tests sending text messages via NATS using nats_bridge.py smartsend
+"""
+
+import sys
+import os
+
+# Add src to path for import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..', 'src'))
+
+from nats_bridge import smartsend, log_trace
+import uuid
+
+# Configuration
+SUBJECT = "/NATSBridge_text_test"
+NATS_URL = "nats://nats.yiem.cc:4222"
+FILESERVER_URL = "http://192.168.88.104:8080"
+SIZE_THRESHOLD = 1_000_000  # 1MB
+
+# Create correlation ID for tracing
+correlation_id = str(uuid.uuid4())
+
+
+def main():
+    # Create a small text (will use direct transport)
+    small_text = "Hello, this is a small text message. Testing direct transport via NATS."
+    
+    # Create a large text (will use link transport if > 1MB)
+    # Generate a larger text (~2MB to ensure link transport)
+    large_text = "\n".join([
+        f"Line {i}: This is a sample text line with some content to pad the size. " * 100 
+        for i in range(500)
+    ])
+    
+    # Test data 1: small text
+    data1 = ("small_text", small_text, "text")
+    
+    # Test data 2: large text
+    data2 = ("large_text", large_text, "text")
+    
+    log_trace(correlation_id, f"Starting smartsend for subject: {SUBJECT}")
+    log_trace(correlation_id, f"Correlation ID: {correlation_id}")
+    
+    # Use smartsend with text type
+    # For small text: will use direct transport (Base64 encoded UTF-8)
+    # For large text: will use link transport (uploaded to fileserver)
+    env, env_json_str = smartsend(
+        SUBJECT,
+        [data1, data2],  # List of (dataname, data, type) tuples
+        nats_url=NATS_URL,
+        fileserver_url=FILESERVER_URL,
+        size_threshold=SIZE_THRESHOLD,
+        correlation_id=correlation_id,
+        msg_purpose="chat",
+        sender_name="text_sender",
+        receiver_name="",
+        receiver_id="",
+        reply_to="",
+        reply_to_msg_id="",
+        is_publish=True  # Publish the message to NATS
+    )
+    
+    log_trace(correlation_id, f"Sent message with {len(env.payloads)} payloads")
+    
+    # Log transport type for each payload
+    for i, payload in enumerate(env.payloads):
+        log_trace(correlation_id, f"Payload {i+1} ('{payload.dataname}'):")
+        log_trace(correlation_id, f"  Transport: {payload.transport}")
+        log_trace(correlation_id, f"  Type: {payload.type}")
+        log_trace(correlation_id, f"  Size: {payload.size} bytes")
+        log_trace(correlation_id, f"  Encoding: {payload.encoding}")
+        
+        if payload.transport == "link":
+            log_trace(correlation_id, f"  URL: {payload.data}")
+    
+    print(f"Test completed. Correlation ID: {correlation_id}")
+
+
+if __name__ == "__main__":
+    main()