update

Reviewed-on: #7

Manifest.toml

@@ -2,7 +2,7 @@
 
 julia_version = "1.12.5"
 manifest_format = "2.0"
-project_hash = "8a7a8b88d777403234a6816e699fb0ab1e991aac"
+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"

Project.toml

@@ -1,5 +1,11 @@
+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"
@@ -9,3 +15,7 @@ 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"

README.md

@@ -0,0 +1,968 @@
+# NATSBridge
+
+A high-performance, bi-directional data bridge between **Julia**, **JavaScript**, and **Python/Micropython** applications using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
+
+[![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
+[![NATS](https://img.shields.io/badge/NATS-Enabled-green.svg)](https://nats.io)
+
+---
+
+## Table of Contents
+
+- [Overview](#overview)
+- [Features](#features)
+- [Architecture](#architecture)
+- [Installation](#installation)
+- [Quick Start](#quick-start)
+- [API Reference](#api-reference)
+- [Payload Types](#payload-types)
+- [Transport Strategies](#transport-strategies)
+- [Examples](#examples)
+- [Testing](#testing)
+- [License](#license)
+
+---
+
+## Overview
+
+NATSBridge enables seamless communication across Julia, JavaScript, and Python/Micropython applications through NATS, with intelligent transport selection based on payload size:
+
+| Transport | Payload Size | Method |
+|-----------|--------------|--------|
+| **Direct** | < 1MB | Sent directly via NATS (Base64 encoded) |
+| **Link** | >= 1MB | Uploaded to HTTP file server, URL sent via NATS |
+
+### Use Cases
+
+- **Chat Applications**: Text, images, audio, video in a single message
+- **File Transfer**: Efficient transfer of large files using claim-check pattern
+- **Streaming Data**: Sensor data, telemetry, and analytics pipelines
+- **Cross-Platform Communication**: Julia ↔ JavaScript ↔ Python/Micropython
+- **IoT Devices**: Micropython devices sending data to cloud services
+
+---
+
+## Features
+
+- ✅ **Bi-directional messaging** between Julia, JavaScript, and Python/Micropython
+- ✅ **Multi-payload support** - send multiple payloads with different types in one message
+- ✅ **Automatic transport selection** - direct vs link based on payload size
+- ✅ **Claim-Check pattern** for payloads > 1MB
+- ✅ **Apache Arrow IPC** support for tabular data (zero-copy reading)
+- ✅ **Exponential backoff** for reliable file server downloads
+- ✅ **Correlation ID tracking** for message tracing
+- ✅ **Reply-to support** for request-response patterns
+- ✅ **JetStream support** for message replay and durability
+- ✅ **Lightweight Micropython implementation** for microcontrollers
+
+---
+
+## Architecture
+
+### System Components
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│                     NATSBridge Architecture                         │
+├─────────────────────────────────────────────────────────────────────┤
+│  ┌──────────────┐    ┌──────────────┐    ┌──────────────┐           │
+│  │   Julia      │    │  JavaScript  │    │  Python/     │           │
+│  │  (NATS.jl)   │◄──►│  (nats.js)   │◄──►│  Micropython │           │
+│  └──────────────┘    └──────────────┘    └──────────────┘           │
+│       │                    │                    │                   │
+│       ▼                    ▼                    ▼                   │
+│    ┌─────────────────────────────────────────────────────┐          │
+│    │                    NATS                             │          │
+│    │               (Message Broker)                      │          │
+│    └─────────────────────────────────────────────────────┘          │
+│                              │                                      │
+│                              ▼                                      │
+│                    ┌──────────────────────┐                         │
+│                    │  File Server         │                         │
+│                    │  (HTTP Upload/Get)   │                         │
+│                    └──────────────────────┘                         │
+└─────────────────────────────────────────────────────────────────────┘
+```
+
+### Message Flow
+
+1. **Sender** creates a message envelope with payloads
+2. **NATSBridge** serializes and encodes payloads based on type
+3. **Transport Decision**: Small payloads go directly to NATS, large payloads are uploaded to file server
+4. **NATS** routes messages to subscribers
+5. **Receiver** fetches payloads (from NATS or file server)
+6. **NATSBridge** deserializes and decodes payloads
+
+---
+
+## Installation
+
+### Prerequisites
+
+- **NATS Server** (v2.10+ recommended)
+- **HTTP File Server** (optional, for payloads > 1MB)
+
+### Julia
+
+```julia
+using Pkg
+Pkg.add("NATS")
+Pkg.add("https://git.yiem.cc/ton/NATSBridge")
+```
+
+### JavaScript
+
+```bash
+npm install nats.js apache-arrow uuid base64-url
+```
+
+For Node.js:
+```javascript
+const { smartsend, smartreceive } = require('./src/NATSBridge');
+```
+
+For browser:
+```html
+<script src="./src/NATSBridge.js"></script>
+<script>
+  // NATSBridge is available as window.NATSBridge
+</script>
+```
+
+### Python/Micropython
+
+1. Copy [`src/nats_bridge.py`](src/nats_bridge.py) to your device
+2. Install dependencies:
+
+**For Python (desktop):**
+```bash
+pip install nats-py
+```
+
+**For Micropython:**
+- `urequests` for HTTP requests (built-in for ESP32)
+- `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
+data = [("message", "Hello World", "text")]
+env, env_json_str = smartsend("/chat/room1", data, nats_url="nats://localhost:4222")
+print("Message sent!")
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Send a text message
+const { env, env_json_str } = await smartsend("/chat/room1", [
+    { dataname: "message", data: "Hello World", type: "text" }
+], { natsUrl: "nats://localhost:4222" });
+
+console.log("Message sent!");
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Send a text message
+data = [("message", "Hello World", "text")]
+env, env_json_str = NATSBridge.smartsend("/chat/room1", data; nats_url="nats://localhost:4222")
+println("Message sent!")
+```
+
+### Step 4: Receive Messages
+
+#### Python/Micropython
+
+```python
+import nats
+import asyncio
+from nats_bridge import smartreceive
+
+# Configuration
+SUBJECT = "/chat/room1"
+NATS_URL = "nats://localhost:4222"
+
+async def main():
+    # Connect to NATS
+    nc = await nats.connect(NATS_URL)
+    
+    # Subscribe to the subject - msg comes from the callback
+    async def message_handler(msg):
+        # Receive and process message
+        env = smartreceive(msg.data)
+        for dataname, data, type in env["payloads"]:
+            print(f"Received {dataname}: {data}")
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    await asyncio.sleep(120)  # Keep listening
+    await nc.close()
+
+asyncio.run(main())
+```
+
+#### JavaScript
+
+```javascript
+const { smartreceive } = require('./src/NATSBridge');
+const { connect } = require('nats');
+
+// Configuration
+const SUBJECT = "/chat/room1";
+const NATS_URL = "nats://localhost:4222";
+
+async function main() {
+    // Connect to NATS
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    // Subscribe to the subject - msg comes from the async iteration
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        // Receive and process message
+        const env = await smartreceive(msg);
+        for (const payload of env.payloads) {
+            console.log(`Received ${payload.dataname}: ${payload.data}`);
+        }
+    }
+}
+
+main();
+```
+
+#### Julia
+
+```julia
+using NATS, NATSBridge
+
+# Configuration
+const SUBJECT = "/chat/room1"
+const NATS_URL = "nats://localhost:4222"
+
+# Helper: Log with correlation ID
+function log_trace(message)
+    timestamp = Dates.now()
+    println("[$timestamp] $message")
+end
+
+# Receiver: Listen for messages - msg comes from the callback
+function test_receive()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        log_trace("Received message on $(msg.subject)")
+        
+        # Receive and process message
+        env, env_json_str = NATSBridge.smartreceive(msg, fileserverDownloadHandler)
+        for (dataname, data, type) in env["payloads"]
+            println("Received $dataname: $data")
+        end
+    end
+    
+    # Keep listening for 120 seconds
+    sleep(120)
+    NATS.drain(conn)
+end
+
+test_receive()
+```
+
+---
+
+## API Reference
+
+### smartsend
+
+Sends data either directly via NATS or via a fileserver URL, depending on payload size.
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartsend
+
+env, env_json_str = smartsend(
+    subject,                           # NATS subject to publish to
+    data,                              # List of (dataname, data, type) tuples
+    nats_url="nats://localhost:4222",  # NATS server URL
+    fileserver_url="http://localhost:8080",  # File server URL
+    fileserver_upload_handler=plik_oneshot_upload,  # Upload handler function
+    size_threshold=1_000_000,          # Threshold in bytes (default: 1MB)
+    correlation_id=None,               # Optional correlation ID for tracing
+    msg_purpose="chat",                # Message purpose
+    sender_name="NATSBridge",          # Sender name
+    receiver_name="",                  # Receiver name (empty = broadcast)
+    receiver_id="",                    # Receiver UUID (empty = broadcast)
+    reply_to="",                       # Reply topic
+    reply_to_msg_id="",                # Reply message ID
+    is_publish=True                    # Whether to automatically publish to NATS
+)
+```
+
+#### JavaScript
+
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const { env, env_json_str } = await smartsend(
+    subject,                           // NATS subject
+    data,                              // Array of {dataname, data, type}
+    {
+        natsUrl: "nats://localhost:4222",
+        fileserverUrl: "http://localhost:8080",
+        fileserverUploadHandler: customUploadHandler,
+        sizeThreshold: 1_000_000,
+        correlationId: "custom-id",
+        msgPurpose: "chat",
+        senderName: "NATSBridge",
+        receiverName: "",
+        receiverId: "",
+        replyTo: "",
+        replyToMsgId: "",
+        isPublish: true                  // Whether to automatically publish to NATS
+    }
+);
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+env, env_json_str = NATSBridge.smartsend(
+    subject,                           # NATS subject
+    data::AbstractArray{Tuple{String, Any, String}};  # List of (dataname, data, type)
+    nats_url::String = "nats://localhost:4222",
+    fileserver_url = "http://localhost:8080",
+    fileserverUploadHandler::Function = plik_oneshot_upload,
+    size_threshold::Int = 1_000_000,
+    correlation_id::Union{String, Nothing} = nothing,
+    msg_purpose::String = "chat",
+    sender_name::String = "NATSBridge",
+    receiver_name::String = "",
+    receiver_id::String = "",
+    reply_to::String = "",
+    reply_to_msg_id::String = "",
+    is_publish::Bool = true            # Whether to automatically publish to NATS
+)
+# Returns: (msgEnvelope_v1, JSON string)
+# - env: msgEnvelope_v1 object with all envelope metadata and payloads
+# - env_json_str: JSON string representation of the envelope for publishing
+```
+
+### smartreceive
+
+Receives and processes messages from NATS, handling both direct and link transport.
+
+#### Python/Micropython
+
+```python
+from nats_bridge import smartreceive
+
+# Note: For nats-py, use msg.data to pass the raw message data
+env = smartreceive(
+    msg.data,                          # NATS message data (msg.data for nats-py)
+    fileserver_download_handler=_fetch_with_backoff,  # Download handler
+    max_retries=5,                     # Max retry attempts
+    base_delay=100,                    # Initial delay in ms
+    max_delay=5000                     # Max delay in ms
+)
+# Returns: Dict with envelope metadata and 'payloads' field
+```
+
+#### JavaScript
+
+```javascript
+const { smartreceive } = require('./src/NATSBridge');
+
+// Note: msg is the NATS message object from subscription
+const env = await smartreceive(
+    msg,                               // NATS message (raw object from subscription)
+    {
+        fileserverDownloadHandler: customDownloadHandler,
+        maxRetries: 5,
+        baseDelay: 100,
+        maxDelay: 5000
+    }
+);
+// Returns: Object with envelope metadata and payloads array
+```
+
+#### Julia
+
+```julia
+using NATSBridge
+
+# Note: msg is a NATS.Msg object passed from the subscription callback
+env, env_json_str = NATSBridge.smartreceive(
+    msg::NATS.Msg;
+    fileserverDownloadHandler::Function = _fetch_with_backoff,
+    max_retries::Int = 5,
+    base_delay::Int = 100,
+    max_delay::Int = 5000
+)
+# Returns: Dict with envelope metadata and payloads array
+```
+
+---
+
+## Payload Types
+
+| Type | Description | Serialization |
+|------|-------------|---------------|
+| `text` | Plain text strings | UTF-8 bytes |
+| `dictionary` | JSON-serializable dictionaries | JSON |
+| `table` | Tabular data (DataFrames, arrays) | Apache Arrow IPC |
+| `image` | Image data (PNG, JPG) | Raw bytes |
+| `audio` | Audio data (WAV, MP3) | Raw bytes |
+| `video` | Video data (MP4, AVI) | Raw bytes |
+| `binary` | Generic binary data | Raw bytes |
+
+---
+
+## Transport Strategies
+
+### Direct Transport (Payloads < 1MB)
+
+Small payloads are sent directly via NATS with Base64 encoding.
+
+#### Python/Micropython
+```python
+data = [("message", "Hello", "text")]
+smartsend("/topic", data)
+```
+
+#### JavaScript
+```javascript
+await smartsend("/topic", [
+    { dataname: "message", data: "Hello", type: "text" }
+]);
+```
+
+#### Julia
+```julia
+data = [("message", "Hello", "text")]
+smartsend("/topic", data)
+```
+
+### Link Transport (Payloads >= 1MB)
+
+Large payloads are uploaded to an HTTP file server.
+
+#### Python/Micropython
+```python
+data = [("file", large_data, "binary")]
+smartsend("/topic", data, fileserver_url="http://localhost:8080")
+```
+
+#### JavaScript
+```javascript
+await smartsend("/topic", [
+    { dataname: "file", data: largeData, type: "binary" }
+], { fileserverUrl: "http://localhost:8080" });
+```
+
+#### Julia
+```julia
+data = [("file", large_data, "binary")]
+smartsend("/topic", data; fileserver_url="http://localhost:8080")
+```
+
+---
+
+## Examples
+
+All examples include code for **Julia**, **JavaScript**, and **Python/Micropython** unless otherwise specified.
+
+### Example 1: Chat with Mixed Content
+
+Send text, small image, and large file in one message.
+
+#### Python/Micropython
+```python
+from nats_bridge import smartsend
+
+data = [
+    ("message_text", "Hello!", "text"),
+    ("user_avatar", image_data, "image"),
+    ("large_document", large_file_data, "binary")
+]
+
+env, env_json_str = smartsend("/chat/room1", data, fileserver_url="http://localhost:8080")
+```
+
+#### JavaScript
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const { env, env_json_str } = await smartsend("/chat/room1", [
+    { dataname: "message_text", data: "Hello!", type: "text" },
+    { dataname: "user_avatar", data: image_data, type: "image" },
+    { dataname: "large_document", data: large_file_data, type: "binary" }
+], {
+    fileserverUrl: "http://localhost:8080"
+});
+```
+
+#### Julia
+```julia
+using NATSBridge
+
+data = [
+    ("message_text", "Hello!", "text"),
+    ("user_avatar", image_data, "image"),
+    ("large_document", large_file_data, "binary")
+]
+
+env, env_json_str = NATSBridge.smartsend("/chat/room1", data; fileserver_url="http://localhost:8080")
+```
+
+### Example 2: Dictionary Exchange
+
+Send configuration data between platforms.
+
+#### Python/Micropython
+```python
+from nats_bridge import smartsend
+
+config = {
+    "wifi_ssid": "MyNetwork",
+    "wifi_password": "password123",
+    "update_interval": 60
+}
+
+data = [("config", config, "dictionary")]
+env, env_json_str = smartsend("/device/config", data)
+```
+
+#### 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" }
+]);
+```
+
+#### Julia
+```julia
+using NATSBridge
+
+config = Dict(
+    "wifi_ssid" => "MyNetwork",
+    "wifi_password" => "password123",
+    "update_interval" => 60
+)
+
+data = [("config", config, "dictionary")]
+env, env_json_str = NATSBridge.smartsend("/device/config", data)
+```
+
+### Example 3: Table Data (Arrow IPC)
+
+Send tabular data using Apache Arrow IPC format.
+
+#### Python/Micropython
+```python
+import pandas as pd
+from nats_bridge import smartsend
+
+df = pd.DataFrame({
+    "id": [1, 2, 3],
+    "name": ["Alice", "Bob", "Charlie"],
+    "score": [95, 88, 92]
+})
+
+data = [("students", df, "table")]
+env, env_json_str = smartsend("/data/analysis", data)
+```
+
+#### JavaScript
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const tableData = [
+    { id: 1, name: "Alice", score: 95 },
+    { id: 2, name: "Bob", score: 88 },
+    { id: 3, name: "Charlie", score: 92 }
+];
+
+const { env, env_json_str } = await smartsend("/data/analysis", [
+    { dataname: "students", data: tableData, type: "table" }
+]);
+```
+
+#### Julia
+```julia
+using NATSBridge
+using DataFrames
+
+df = DataFrame(
+    id = [1, 2, 3],
+    name = ["Alice", "Bob", "Charlie"],
+    score = [95, 88, 92]
+)
+
+data = [("students", df, "table")]
+env, env_json_str = NATSBridge.smartsend("/data/analysis", data)
+```
+
+### Example 4: Request-Response Pattern with Envelope JSON
+
+Bi-directional communication with reply-to support. The `smartsend` function now returns both the envelope object and a JSON string that can be published directly.
+
+#### Python/Micropython (Requester)
+```python
+from nats_bridge import smartsend
+
+env, env_json_str = smartsend(
+    "/device/command",
+    [("command", {"action": "read_sensor"}, "dictionary")],
+    reply_to="/device/response"
+)
+# env: msgEnvelope_v1 object
+# env_json_str: JSON string for publishing to NATS
+
+# The env_json_str can also be published directly using NATS request-reply pattern
+# nc.request("/device/command", env_json_str, reply_to="/device/response")
+```
+
+#### Python/Micropython (Responder)
+```python
+import nats
+import asyncio
+from nats_bridge import smartreceive, smartsend
+
+# Configuration
+SUBJECT = "/device/command"
+REPLY_SUBJECT = "/device/response"
+NATS_URL = "nats://localhost:4222"
+
+async def main():
+    nc = await nats.connect(NATS_URL)
+    
+    async def message_handler(msg):
+        env = smartreceive(msg.data)
+        for dataname, data, type in env["payloads"]:
+            if data.get("action") == "read_sensor":
+                response = {"sensor_id": "sensor-001", "value": 42.5}
+                smartsend(REPLY_SUBJECT, [("data", response, "dictionary")])
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    await asyncio.sleep(120)
+    await nc.close()
+
+asyncio.run(main())
+```
+
+#### JavaScript (Requester)
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+const { env, env_json_str } = await smartsend("/device/command", [
+    { dataname: "command", data: { action: "read_sensor" }, type: "dictionary" }
+], {
+    replyTo: "/device/response"
+});
+```
+
+#### JavaScript (Responder)
+```javascript
+const { smartreceive, smartsend } = require('./src/NATSBridge');
+const { connect } = require('nats');
+
+// Configuration
+const SUBJECT = "/device/command";
+const REPLY_SUBJECT = "/device/response";
+const NATS_URL = "nats://localhost:4222";
+
+async function main() {
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        const env = await smartreceive(msg);
+        for (const payload of env.payloads) {
+            if (payload.dataname === "command" && payload.data.action === "read_sensor") {
+                const response = { sensor_id: "sensor-001", value: 42.5 };
+                await smartsend(REPLY_SUBJECT, [
+                    { dataname: "data", data: response, type: "dictionary" }
+                ]);
+            }
+        }
+    }
+}
+
+main();
+```
+
+#### Julia (Requester)
+```julia
+using NATSBridge
+
+env, env_json_str = NATSBridge.smartsend(
+    "/device/command",
+    [("command", Dict("action" => "read_sensor"), "dictionary")];
+    reply_to="/device/response"
+)
+```
+
+#### Julia (Responder)
+```julia
+using NATS, NATSBridge
+
+# Configuration
+const SUBJECT = "/device/command"
+const REPLY_SUBJECT = "/device/response"
+const NATS_URL = "nats://localhost:4222"
+
+function test_responder()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        env, env_json_str = NATSBridge.smartreceive(msg, fileserverDownloadHandler)
+        for (dataname, data, type) in env["payloads"]
+            if dataname == "command" && data["action"] == "read_sensor"
+                response = Dict("sensor_id" => "sensor-001", "value" => 42.5)
+                smartsend(REPLY_SUBJECT, [("data", response, "dictionary")])
+            end
+        end
+    end
+    
+    sleep(120)
+    NATS.drain(conn)
+end
+
+test_responder()
+```
+
+### Example 5: Micropython IoT Device
+
+Lightweight Micropython device sending sensor data.
+
+#### Micropython
+```python
+import nats
+import asyncio
+from nats_bridge import smartsend, smartreceive
+
+# Configuration
+SUBJECT = "/device/sensors"
+NATS_URL = "nats://localhost:4222"
+
+async def main():
+    nc = await nats.connect(NATS_URL)
+    
+    # Send sensor data
+    data = [("temperature", "25.5", "text"), ("humidity", 65, "dictionary")]
+    smartsend("/device/sensors", data, nats_url="nats://localhost:4222")
+    
+    # Receive commands - msg comes from the callback
+    async def message_handler(msg):
+        env = smartreceive(msg.data)
+        for dataname, data, type in env["payloads"]:
+            if type == "dictionary" and data.get("action") == "reboot":
+                # Execute reboot
+                pass
+    
+    sid = await nc.subscribe(SUBJECT, cb=message_handler)
+    await asyncio.sleep(120)
+    await nc.close()
+
+asyncio.run(main())
+```
+
+#### JavaScript (Receiver)
+```javascript
+const { smartreceive } = require('./src/NATSBridge');
+const { connect } = require('nats');
+
+// Configuration
+const SUBJECT = "/device/sensors";
+const NATS_URL = "nats://localhost:4222";
+
+async function main() {
+    const nc = await connect({ servers: [NATS_URL] });
+    
+    const sub = nc.subscribe(SUBJECT);
+    
+    for await (const msg of sub) {
+        const env = await smartreceive(msg);
+        for (const payload of env.payloads) {
+            if (payload.dataname === "temperature") {
+                console.log(`Temperature: ${payload.data}`);
+            } else if (payload.dataname === "humidity") {
+                console.log(`Humidity: ${payload.data}`);
+            }
+        }
+    }
+}
+
+main();
+```
+
+#### Julia (Receiver)
+```julia
+using NATS, NATSBridge
+
+# Configuration
+const SUBJECT = "/device/sensors"
+const NATS_URL = "nats://localhost:4222"
+
+function test_receiver()
+    conn = NATS.connect(NATS_URL)
+    NATS.subscribe(conn, SUBJECT) do msg
+        env, env_json_str = NATSBridge.smartreceive(msg, fileserverDownloadHandler)
+        for (dataname, data, type) in env["payloads"]
+            if dataname == "temperature"
+                println("Temperature: $data")
+            elseif dataname == "humidity"
+                println("Humidity: $data")
+            end
+        end
+    end
+    
+    sleep(120)
+    NATS.drain(conn)
+end
+
+test_receiver()
+```
+
+---
+
+## Testing
+
+Run the test scripts to verify functionality:
+
+### Python/Micropython
+
+```bash
+# Basic functionality test
+python test/test_micropython_basic.py
+
+# Text message exchange
+python test/test_micropython_text_sender.py
+python test/test_micropython_text_receiver.py
+
+# Dictionary exchange
+python test/test_micropython_dict_sender.py
+python test/test_micropython_dict_receiver.py
+
+# File transfer
+python test/test_micropython_file_sender.py
+python test/test_micropython_file_receiver.py
+
+# Mixed payload types
+python test/test_micropython_mixed_sender.py
+python test/test_micropython_mixed_receiver.py
+```
+
+### JavaScript
+
+```bash
+# Text message exchange
+node test/test_js_text_sender.js
+node test/test_js_text_receiver.js
+
+# Dictionary exchange
+node test/test_js_dict_sender.js
+node test/test_js_dict_receiver.js
+
+# File transfer
+node test/test_js_file_sender.js
+node test/test_js_file_receiver.js
+
+# Mixed payload types
+node test/test_js_mix_payload_sender.js
+node test/test_js_mix_payloads_receiver.js
+
+# Table exchange
+node test/test_js_table_sender.js
+node test/test_js_table_receiver.js
+```
+
+### Julia
+
+```julia
+# Text message exchange
+julia test/test_julia_text_sender.jl
+julia test/test_julia_text_receiver.jl
+
+# Dictionary exchange
+julia test/test_julia_dict_sender.jl
+julia test/test_julia_dict_receiver.jl
+
+# File transfer
+julia test/test_julia_file_sender.jl
+julia test/test_julia_file_receiver.jl
+
+# Mixed payload types
+julia test/test_julia_mix_payloads_sender.jl
+julia test/test_julia_mix_payloads_receiver.jl
+
+# Table exchange
+julia test/test_julia_table_sender.jl
+julia test/test_julia_table_receiver.jl
+```
+
+---
+
+## License
+
+MIT License
+
+Copyright (c) 2026 NATSBridge Contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

docs/architecture.md

@@ -1,8 +1,13 @@
-# Architecture Documentation: Bi-Directional Data Bridge (Julia ↔ JavaScript)
+# Architecture Documentation: Bi-Directional Data Bridge
 
 ## Overview
 
-This document describes the architecture for a high-performance, bi-directional data bridge between a Julia service and a JavaScript (Node.js) service using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
+This document describes the architecture for a high-performance, bi-directional data bridge between **Julia**, **JavaScript**, and **Python/Micropython** applications using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
+
+The system enables seamless communication across all three platforms:
+- **Julia ↔ JavaScript** bi-directional messaging
+- **JavaScript ↔ Python/Micropython** bi-directional messaging
+- **Julia ↔ Python/Micropython** bi-directional messaging (via JSON serialization)
 
 ### File Server Handler Architecture
 
@@ -12,16 +17,16 @@ The system uses **handler functions** to abstract file server operations, allowi
 
 ```julia
 # Upload handler - uploads data to file server and returns URL
-# The handler is passed to smartsend as fileserverUploadHandler parameter
+# The handler is passed to smartsend as fileserver_upload_handler parameter
-# It receives: (fileserver_url::String, dataname::String, data::Vector{UInt8})
+# It receives: (file_server_url::String, dataname::String, data::Vector{UInt8})
 # Returns: Dict{String, Any} with keys: "status", "uploadid", "fileid", "url"
-fileserverUploadHandler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+fileserver_upload_handler(file_server_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
 
 # Download handler - fetches data from file server URL with exponential backoff
-# The handler is passed to smartreceive as fileserverDownloadHandler parameter
+# The handler is passed to smartreceive as fileserver_download_handler parameter
 # It receives: (url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)
 # Returns: Vector{UInt8} (the downloaded data)
-fileserverDownloadHandler(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)::Vector{UInt8}
+fileserver_download_handler(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)::Vector{UInt8}
 ```
 
 This design allows the system to support multiple file server backends without changing the core messaging logic.
@@ -35,8 +40,24 @@ The system uses a **standardized list-of-tuples format** for all payload operati
 # 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)
+# Output format for smartreceive (returns a dictionary with payloads field containing list of tuples)
-[(dataname1, data1, type1), (dataname2, data2, type2), ...]
+# Returns: Dict with envelope metadata and payloads field containing Vector{Tuple{String, Any, String}}
+# {
+#   "correlation_id": "...",
+#   "msg_id": "...",
+#   "timestamp": "...",
+#   "send_to": "...",
+#   "msg_purpose": "...",
+#   "sender_name": "...",
+#   "sender_id": "...",
+#   "receiver_name": "...",
+#   "receiver_id": "...",
+#   "reply_to": "...",
+#   "reply_to_msg_id": "...",
+#   "broker_url": "...",
+#   "metadata": {...},
+#   "payloads": [(dataname1, data1, type1), (dataname2, data2, type2), ...]
+# }
 ```
 
 **Supported Types:**
@@ -57,17 +78,16 @@ This design allows per-payload type specification, enabling **mixed-content mess
 smartsend(
     "/test",
     [("dataname1", data1, "dictionary")],  # List with one tuple (data, type)
-    nats_url="nats://localhost:4222",
+    broker_url="nats://localhost:4222",
-    fileserverUploadHandler=plik_oneshot_upload,
+    fileserver_upload_handler=plik_oneshot_upload
-    metadata=user_provided_envelope_level_metadata
 )
 
 # Multiple payloads in one message with different types
 smartsend(
     "/test",
     [("dataname1", data1, "dictionary"), ("dataname2", data2, "table")],
-    nats_url="nats://localhost:4222",
+    broker_url="nats://localhost:4222",
-    fileserverUploadHandler=plik_oneshot_upload
+    fileserver_upload_handler=plik_oneshot_upload
 )
 
 # Mixed content (e.g., chat with text, image, audio)
@@ -78,12 +98,14 @@ smartsend(
         ("user_image", image_data, "image"),
         ("audio_clip", audio_data, "audio")
     ],
-    nats_url="nats://localhost:4222"
+    broker_url="nats://localhost:4222"
 )
 
-# Receive always returns a list
+# Receive returns a dictionary envelope with all metadata and deserialized payloads
-payloads = smartreceive(msg, fileserverDownloadHandler, max_retries, base_delay, max_delay)
+env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff, max_retries=5, base_delay=100, max_delay=5000)
-# payloads = [("dataname1", data1, type1), ("dataname2", data2, type2), ...]
+# env["payloads"] = [("dataname1", data1, type1), ("dataname2", data2, type2), ...]
+# env["correlation_id"], env["msg_id"], etc.
+# env is a dictionary containing envelope metadata and payloads field
 ```
 
 ## Architecture Diagram
@@ -116,48 +138,48 @@ flowchart TD
 
 ## System Components
 
-### 1. msgEnvelope_v1 - Message Envelope
+### 1. msg_envelope_v1 - Message Envelope
 
-The `msgEnvelope_v1` structure provides a comprehensive message format for bidirectional communication between Julia and JavaScript services.
+The `msg_envelope_v1` structure provides a comprehensive message format for bidirectional communication between Julia, JavaScript, and Python/Micropython applications.
 
 **Julia Structure:**
 ```julia
-struct msgEnvelope_v1
+struct msg_envelope_v1
-  correlationId::String       # Unique identifier to track messages across systems
+  correlation_id::String       # Unique identifier to track messages across systems
-  msgId::String               # This message id
+  msg_id::String               # This message id
-  timestamp::String           # Message published timestamp
+  timestamp::String            # Message published timestamp
   
-  sendTo::String              # Topic/subject the sender sends to
+  send_to::String              # Topic/subject the sender sends to
-  msgPurpose::String          # Purpose of this message (ACK | NACK | updateStatus | shutdown | ...)
+  msg_purpose::String          # Purpose of this message (ACK | NACK | updateStatus | shutdown | ...)
-  senderName::String          # Sender name (e.g., "agent-wine-web-frontend")
+  sender_name::String          # Sender name (e.g., "agent-wine-web-frontend")
-  senderId::String            # Sender id (uuid4)
+  sender_id::String            # Sender id (uuid4)
-  receiverName::String        # Message receiver name (e.g., "agent-backend")
+  receiver_name::String        # Message receiver name (e.g., "agent-backend")
-  receiverId::String          # Message receiver id (uuid4 or nothing for broadcast)
+  receiver_id::String          # Message receiver id (uuid4 or nothing for broadcast)
-  replyTo::String             # Topic to reply to
+  reply_to::String             # Topic to reply to
-  replyToMsgId::String        # Message id this message is replying to
+  reply_to_msg_id::String      # Message id this message is replying to
-  brokerURL::String           # NATS server address
+  broker_url::String           # NATS server address
   
   metadata::Dict{String, Any}
-  payloads::AbstractArray{msgPayload_v1}  # Multiple payloads stored here
+  payloads::Vector{msg_payload_v1}  # Multiple payloads stored here
 end
 ```
 
 **JSON Schema:**
 ```json
 {
-  "correlationId": "uuid-v4-string",
+  "correlation_id": "uuid-v4-string",
-  "msgId": "uuid-v4-string",
+  "msg_id": "uuid-v4-string",
   "timestamp": "2024-01-15T10:30:00Z",
   
-  "sendTo": "topic/subject",
+  "send_to": "topic/subject",
-  "msgPurpose": "ACK | NACK | updateStatus | shutdown | chat",
+  "msg_purpose": "ACK | NACK | updateStatus | shutdown | chat",
-  "senderName": "agent-wine-web-frontend",
+  "sender_name": "agent-wine-web-frontend",
-  "senderId": "uuid4",
+  "sender_id": "uuid4",
-  "receiverName": "agent-backend",
+  "receiver_name": "agent-backend",
-  "receiverId": "uuid4",
+  "receiver_id": "uuid4",
-  "replyTo": "topic",
+  "reply_to": "topic",
-  "replyToMsgId": "uuid4",
+  "reply_to_msg_id": "uuid4",
-  "brokerURL": "nats://localhost:4222",
+  "broker_url": "nats://localhost:4222",
   
   "metadata": {
 
@@ -167,7 +189,7 @@ end
     {
       "id": "uuid4",
       "dataname": "login_image",
-      "type": "image",
+      "payload_type": "image",
       "transport": "direct",
       "encoding": "base64",
       "size": 15433,
@@ -179,7 +201,7 @@ end
     {
       "id": "uuid4",
       "dataname": "large_data",
-      "type": "table",
+      "payload_type": "table",
       "transport": "link",
       "encoding": "none",
       "size": 524288,
@@ -192,16 +214,16 @@ end
 }
 ```
 
-### 2. msgPayload_v1 - Payload Structure
+### 2. msg_payload_v1 - Payload Structure
 
-The `msgPayload_v1` structure provides flexible payload handling for various data types.
+The `msg_payload_v1` structure provides flexible payload handling for various data types across all supported platforms.
 
 **Julia Structure:**
 ```julia
-struct msgPayload_v1
+struct msg_payload_v1
   id::String                    # Id of this payload (e.g., "uuid4")
   dataname::String              # Name of this payload (e.g., "login_image")
-  type::String                  # "text | dictionary | table | image | audio | video | binary"
+  payload_type::String          # "text | dictionary | table | image | audio | video | binary"
   transport::String             # "direct | link"
   encoding::String              # "none | json | base64 | arrow-ipc"
   size::Integer                 # Data size in bytes
@@ -222,15 +244,15 @@ end
 ┌─────────────────────────────────────────────────────────────┐
 │                     smartsend Function                      │
 │  Accepts: [(dataname1, data1, type1), ...]                  │
-│  (No standalone type parameter - type per payload)          │
+│  (Type is per payload, not standalone)                      │
 └─────────────────────────────────────────────────────────────┘
                              │
                              ▼
 ┌─────────────────────────────────────────────────────────────┐
 │  For each payload:                                          │
-│  1. Extract type from tuple                                │
+│  1. Extract type from tuple                                 │
-│  2. Serialize based on type                                │
+│  2. Serialize based on type                                 │
-│  3. Check payload size                                     │
+│  3. Check payload size                                      │
 └─────────────────────────────────────────────────────────────┘
                              │
             ┌────────────────┴─-────────────────┐
@@ -249,19 +271,77 @@ end
       └─────────────────┘                 └─────────────────┘
 ```
 
-### 4. Julia Module Architecture
+### 4. Cross-Platform Architecture
+
+```mermaid
+flowchart TD
+    subgraph PythonMicropython
+        Py[Python/Micropython]
+        PySmartSend[smartsend]
+        PySmartReceive[smartreceive]
+    end
+
+    subgraph JavaScript
+        JS[JavaScript]
+        JSSmartSend[smartsend]
+        JSSmartReceive[smartreceive]
+    end
+
+    subgraph Julia
+        Julia[Julia]
+        JuliaSmartSend[smartsend]
+        JuliaSmartReceive[smartreceive]
+    end
+
+    subgraph NATS
+        NATSServer[NATS Server]
+    end
+
+    PySmartSend --> NATSServer
+    JSSmartSend --> NATSServer
+    JuliaSmartSend --> NATSServer
+    NATSServer --> PySmartReceive
+    NATSServer --> JSSmartReceive
+    NATSServer --> JuliaSmartReceive
+
+    style PythonMicropython fill:#e1f5fe
+    style JavaScript fill:#f3e5f5
+    style Julia fill:#e8f5e9
+```
+
+### 5. Python/Micropython Module Architecture
 
 ```mermaid
 graph TD
-    subgraph JuliaModule
+    subgraph PyModule
-        smartsendJulia[smartsend Julia]
+        PySmartSend[smartsend]
         SizeCheck[Size Check]
         DirectPath[Direct Path]
         LinkPath[Link Path]
         HTTPClient[HTTP Client]
     end
 
-    smartsendJulia --> SizeCheck
+    PySmartSend --> SizeCheck
+    SizeCheck -->|< 1MB| DirectPath
+    SizeCheck -->|>= 1MB| LinkPath
+    LinkPath --> HTTPClient
+
+    style PyModule fill:#b3e5fc
+```
+
+### 6. Julia Module Architecture
+
+```mermaid
+graph TD
+    subgraph JuliaModule
+        JuliaSmartSend[smartsend]
+        SizeCheck[Size Check]
+        DirectPath[Direct Path]
+        LinkPath[Link Path]
+        HTTPClient[HTTP Client]
+    end
+
+    JuliaSmartSend --> SizeCheck
     SizeCheck -->|< 1MB| DirectPath
     SizeCheck -->|>= 1MB| LinkPath
     LinkPath --> HTTPClient
@@ -269,19 +349,19 @@ graph TD
     style JuliaModule fill:#c5e1a5
 ```
 
-### 5. JavaScript Module Architecture
+### 7. JavaScript Module Architecture
 
 ```mermaid
 graph TD
     subgraph JSModule
-        smartsendJS[smartsend JS]
+        JSSmartSend[smartsend]
-        smartreceiveJS[smartreceive JS]
+        JSSmartReceive[smartreceive]
         JetStreamConsumer[JetStream Pull Consumer]
         ApacheArrow[Apache Arrow]
     end
 
-    smartsendJS --> NATS
+    JSSmartSend --> NATS
-    smartreceiveJS --> JetStreamConsumer
+    JSSmartReceive --> JetStreamConsumer
     JetStreamConsumer --> ApacheArrow
 
     style JSModule fill:#f3e5f5
@@ -303,13 +383,32 @@ graph TD
 ```julia
 function smartsend(
   subject::String,
-  data::AbstractArray{Tuple{String, Any, String}};  # No standalone type parameter
+  data::AbstractArray{Tuple{String, Any, String}, 1};  # List of (dataname, data, type) tuples
-  nats_url::String = "nats://localhost:4222",
+  broker_url::String = DEFAULT_BROKER_URL,  # NATS server URL
-  fileserverUploadHandler::Function = plik_oneshot_upload,
+  fileserver_url = DEFAULT_FILESERVER_URL,
-  size_threshold::Int = 1_000_000  # 1MB
+  fileserver_upload_handler::Function = plik_oneshot_upload,
+  size_threshold::Int = DEFAULT_SIZE_THRESHOLD,
+  correlation_id::Union{String, Nothing} = nothing,
+  msg_purpose::String = "chat",
+  sender_name::String = "NATSBridge",
+  receiver_name::String = "",
+  receiver_id::String = "",
+  reply_to::String = "",
+  reply_to_msg_id::String = "",
+  is_publish::Bool = true   # Whether to automatically publish to NATS
 )
 ```
 
+**Return Value:**
+- Returns a tuple `(env, env_json_str)` where:
+  - `env::msg_envelope_v1` - The envelope object containing all metadata and payloads
+  - `env_json_str::String` - JSON string representation of the envelope for publishing
+
+**Options:**
+- `is_publish::Bool = true` - When `true` (default), the message is automatically published to NATS. When `false`, the function returns the envelope and JSON string without publishing, allowing manual publishing via NATS request-reply pattern.
+
+The envelope object can be accessed directly for programmatic use, while the JSON string can be published directly to NATS using the request-reply pattern.
+
 **Input Format:**
 - `data::AbstractArray{Tuple{String, Any, String}}` - **Must be a list of (dataname, data, type) tuples**: `[("dataname1", data1, "type1"), ("dataname2", data2, "type2"), ...]`
 - Even for single payloads: `[(dataname1, data1, "type1")]`
@@ -326,8 +425,8 @@ function smartsend(
 
 ```julia
 function smartreceive(
-    msg::NATS.Message,
+    msg::NATS.Msg;
-    fileserverDownloadHandler::Function;
+    fileserver_download_handler::Function = _fetch_with_backoff,
     max_retries::Int = 5,
     base_delay::Int = 100,
     max_delay::Int = 5000
@@ -336,86 +435,209 @@ function smartreceive(
     # Iterate through all payloads
     # For each payload: check transport type
     #   If direct: decode Base64 payload
-    #   If link: fetch from URL with exponential backoff using fileserverDownloadHandler
+    #   If link: fetch from URL with exponential backoff using fileserver_download_handler
     # Deserialize payload based on type
-    # Return list of (dataname, data, type) tuples
+    # Return envelope dictionary with all metadata and deserialized payloads
 end
 ```
 
 **Output Format:**
-- Always returns a list of tuples: `[(dataname1, data1, type1), (dataname2, data2, type2), ...]`
+- Returns a dictionary (key-value map) containing all envelope fields:
-- Even for single payloads: `[(dataname1, data1, type1)]`
+  - `correlation_id`, `msg_id`, `timestamp`, `send_to`, `msg_purpose`, `sender_name`, `sender_id`, `receiver_name`, `receiver_id`, `reply_to`, `reply_to_msg_id`, `broker_url`
+  - `metadata` - Message-level metadata dictionary
+  - `payloads` - List of dictionaries, each containing deserialized payload data
 
 **Process Flow:**
-1. Parse the JSON envelope to extract the `payloads` array
+1. Parse the JSON envelope to extract all fields
 2. Iterate through each payload in `payloads`
 3. For each payload:
    - Determine transport type (`direct` or `link`)
    - If `direct`: decode Base64 data from the message
-   - If `link`: fetch data from URL using exponential backoff (via `fileserverDownloadHandler`)
+   - If `link`: fetch data from URL using exponential backoff (via `fileserver_download_handler`)
    - Deserialize based on payload type (`dictionary`, `table`, `binary`, etc.)
-4. Return list of `(dataname, data, type)` tuples
+4. Return envelope dictionary with `payloads` field containing list of `(dataname, data, type)` tuples
 
-**Note:** The `fileserverDownloadHandler` receives `(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)` and returns `Vector{UInt8}`.
+**Note:** The `fileserver_download_handler` receives `(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)` and returns `Vector{UInt8}`.
 
 ### JavaScript Implementation
 
 #### Dependencies
 - `nats.js` - Core NATS functionality
 - `apache-arrow` - Arrow IPC serialization
-- `uuid` - Correlation ID generation
+- `uuid` - Correlation ID and message ID generation
+- `base64-arraybuffer` - Base64 encoding/decoding
+- `node-fetch` or `fetch` - HTTP client for file server
 
 #### smartsend Function
 
 ```javascript
-async function smartsend(subject, data, options = {})
+async function smartsend(
-    // data format: [(dataname, data, type), ...]
+  subject,
-    // options object should include:
+  data,  // List of (dataname, data, type) tuples: [(dataname1, data1, type1), ...]
-    // - natsUrl: NATS server URL
+  options = {}
-    // - fileserverUrl: base URL of the file server
+)
-    // - sizeThreshold: threshold in bytes for transport selection
-    // - correlationId: optional correlation ID for tracing
 ```
 
+**Options:**
+- `broker_url` (String) - NATS server URL (default: `"nats://localhost:4222"`)
+- `fileserver_url` (String) - Base URL of the file server (default: `"http://localhost:8080"`)
+- `size_threshold` (Number) - Threshold in bytes for transport selection (default: `1048576` = 1MB)
+- `correlation_id` (String) - Optional correlation ID for tracing
+- `msg_purpose` (String) - Purpose of the message (default: `"chat"`)
+- `sender_name` (String) - Sender name (default: `"NATSBridge"`)
+- `receiver_name` (String) - Message receiver name (default: `""`)
+- `receiver_id` (String) - Message receiver ID (default: `""`)
+- `reply_to` (String) - Topic to reply to (default: `""`)
+- `reply_to_msg_id` (String) - Message ID this message is replying to (default: `""`)
+- `fileserver_upload_handler` (Function) - Custom upload handler function
+
+**Return Value:**
+- Returns a Promise that resolves to an object containing:
+  - `env` - The envelope object containing all metadata and payloads
+  - `env_json_str` - JSON string representation of the envelope for publishing
+  - `published` - Boolean indicating whether the message was automatically published to NATS
+
 **Input Format:**
 - `data` - **Must be a list of (dataname, data, type) tuples**: `[(dataname1, data1, "type1"), (dataname2, data2, "type2"), ...]`
 - Even for single payloads: `[(dataname1, data1, "type1")]`
 - Each payload can have a different type, enabling mixed-content messages
+- Supported types: `"text"`, `"dictionary"`, `"table"`, `"image"`, `"audio"`, `"video"`, `"binary"`
 
 **Flow:**
-1. Iterate through the list of (dataname, data, type) tuples
+1. Generate correlation ID and message ID if not provided
-2. For each payload: extract the type from the tuple and serialize accordingly
+2. Iterate through the list of `(dataname, data, type)` tuples
-3. Check payload size
+3. For each payload:
-4. If < threshold: publish directly to NATS
+   - Serialize based on payload type
-5. If >= threshold: upload to HTTP server, publish NATS with URL
+   - Check payload size
+   - If < threshold: Base64 encode and include in envelope
+   - If >= threshold: Upload to HTTP server, store URL in envelope
+4. Publish the JSON envelope to NATS
+5. Return envelope object and JSON string
 
 #### smartreceive Handler
 
 ```javascript
 async function smartreceive(msg, options = {})
-    // options object should include:
-    // - fileserverDownloadHandler: function to fetch data from file server URL
-    // - max_retries: maximum retry attempts for fetching URL
-    // - base_delay: initial delay for exponential backoff in ms
-    // - max_delay: maximum delay for exponential backoff in ms
-    // - correlationId: optional correlation ID for tracing
 ```
 
+**Options:**
+- `fileserver_download_handler` (Function) - Custom download handler function
+- `max_retries` (Number) - Maximum retry attempts for fetching URL (default: `5`)
+- `base_delay` (Number) - Initial delay for exponential backoff in ms (default: `100`)
+- `max_delay` (Number) - Maximum delay for exponential backoff in ms (default: `5000`)
+- `correlation_id` (String) - Optional correlation ID for tracing
+
+**Output Format:**
+- Returns a Promise that resolves to an object containing all envelope fields:
+  - `correlation_id`, `msg_id`, `timestamp`, `send_to`, `msg_purpose`, `sender_name`, `sender_id`, `receiver_name`, `receiver_id`, `reply_to`, `reply_to_msg_id`, `broker_url`
+  - `metadata` - Message-level metadata dictionary
+  - `payloads` - List of dictionaries, each containing deserialized payload data with keys: `dataname`, `data`, `payload_type`
+
 **Process Flow:**
-1. Parse the JSON envelope to extract the `payloads` array
+1. Parse the JSON envelope to extract all fields
-2. Iterate through each payload in `payloads`
+2. Iterate through each payload in `payloads` array
 3. For each payload:
    - Determine transport type (`direct` or `link`)
-   - If `direct`: decode Base64 data from the message
+   - If `direct`: Base64 decode the data from the message
-   - If `link`: fetch data from URL using exponential backoff
+   - If `link`: Fetch data from URL using exponential backoff (via `fileserver_download_handler`)
    - Deserialize based on payload type (`dictionary`, `table`, `binary`, etc.)
-4. Return list of `(dataname, data, type)` tuples
+4. Return envelope object with `payloads` field containing list of `(dataname, data, type)` tuples
+
+**Note:** The `fileserver_download_handler` receives `(url, max_retries, base_delay, max_delay, correlation_id)` and returns `ArrayBuffer` or `Uint8Array`.
+
+### Python/Micropython Implementation
+
+#### Dependencies
+- `nats-python` - Core NATS functionality
+- `pyarrow` - Arrow IPC serialization
+- `uuid` - Correlation ID and message ID generation
+- `base64` - Base64 encoding/decoding
+- `requests` or `aiohttp` - HTTP client for file server
+
+#### smartsend Function
+
+```python
+async def smartsend(
+    subject: str,
+    data: List[Tuple[str, Any, str]],  # List of (dataname, data, type) tuples
+    options: Dict = {}
+)
+```
+
+**Options:**
+- `broker_url` (str) - NATS server URL (default: `"nats://localhost:4222"`)
+- `fileserver_url` (str) - Base URL of the file server (default: `"http://localhost:8080"`)
+- `size_threshold` (int) - Threshold in bytes for transport selection (default: `1048576` = 1MB)
+- `correlation_id` (str) - Optional correlation ID for tracing
+- `msg_purpose` (str) - Purpose of the message (default: `"chat"`)
+- `sender_name` (str) - Sender name (default: `"NATSBridge"`)
+- `receiver_name` (str) - Message receiver name (default: `""`)
+- `receiver_id` (str) - Message receiver ID (default: `""`)
+- `reply_to` (str) - Topic to reply to (default: `""`)
+- `reply_to_msg_id` (str) - Message ID this message is replying to (default: `""`)
+- `fileserver_upload_handler` (Callable) - Custom upload handler function
+
+**Return Value:**
+- Returns a tuple `(env, env_json_str)` where:
+  - `env` - The envelope dictionary containing all metadata and payloads
+  - `env_json_str` - JSON string representation of the envelope for publishing
+
+**Input Format:**
+- `data` - **Must be a list of (dataname, data, type) tuples**: `[(dataname1, data1, "type1"), (dataname2, data2, "type2"), ...]`
+- Even for single payloads: `[(dataname1, data1, "type1")]`
+- Each payload can have a different type, enabling mixed-content messages
+- Supported types: `"text"`, `"dictionary"`, `"table"`, `"image"`, `"audio"`, `"video"`, `"binary"`
+
+**Flow:**
+1. Generate correlation ID and message ID if not provided
+2. Iterate through the list of `(dataname, data, type)` tuples
+3. For each payload:
+   - Serialize based on payload type
+   - Check payload size
+   - If < threshold: Base64 encode and include in envelope
+   - If >= threshold: Upload to HTTP server, store URL in envelope
+4. Publish the JSON envelope to NATS
+5. Return envelope dictionary and JSON string
+
+#### smartreceive Handler
+
+```python
+async def smartreceive(
+    msg: NATS.Message,
+    options: Dict = {}
+)
+```
+
+**Options:**
+- `fileserver_download_handler` (Callable) - Custom download handler function
+- `max_retries` (int) - Maximum retry attempts for fetching URL (default: `5`)
+- `base_delay` (int) - Initial delay for exponential backoff in ms (default: `100`)
+- `max_delay` (int) - Maximum delay for exponential backoff in ms (default: `5000`)
+- `correlation_id` (str) - Optional correlation ID for tracing
+
+**Output Format:**
+- Returns a dictionary containing all envelope fields:
+  - `correlation_id`, `msg_id`, `timestamp`, `send_to`, `msg_purpose`, `sender_name`, `sender_id`, `receiver_name`, `receiver_id`, `reply_to`, `reply_to_msg_id`, `broker_url`
+  - `metadata` - Message-level metadata dictionary
+  - `payloads` - List of tuples, each containing `(dataname, data, payload_type)` with deserialized payload data
+
+**Process Flow:**
+1. Parse the JSON envelope to extract all fields
+2. Iterate through each payload in `payloads` list
+3. For each payload:
+   - Determine transport type (`direct` or `link`)
+   - If `direct`: Base64 decode the data from the message
+   - If `link`: Fetch data from URL using exponential backoff (via `fileserver_download_handler`)
+   - Deserialize based on payload type (`dictionary`, `table`, `binary`, etc.)
+4. Return envelope dictionary with `payloads` field containing list of `(dataname, data, type)` tuples
+
+**Note:** The `fileserver_download_handler` receives `(url: str, max_retries: int, base_delay: int, max_delay: int, correlation_id: str)` and returns `bytes`.
 
 ## Scenario Implementations
 
 ### Scenario 1: Command & Control (Small Dictionary)
 
-**Julia (Receiver):**
+**Julia (Sender/Receiver):**
 ```julia
 # Subscribe to control subject
 # Parse JSON envelope
@@ -423,15 +645,21 @@ async function smartreceive(msg, options = {})
 # Send acknowledgment
 ```
 
-**JavaScript (Sender):**
+**JavaScript (Sender/Receiver):**
 ```javascript
 // Create small dictionary config
 // Send via smartsend with type="dictionary"
 ```
 
+**Python/Micropython (Sender/Receiver):**
+```python
+# Create small dictionary config
+# Send via smartsend with type="dictionary"
+```
+
 ### Scenario 2: Deep Dive Analysis (Large Arrow Table)
 
-**Julia (Sender):**
+**Julia (Sender/Receiver):**
 ```julia
 # Create large DataFrame
 # Convert to Arrow IPC stream
@@ -440,7 +668,7 @@ async function smartreceive(msg, options = {})
 # Publish NATS with URL
 ```
 
-**JavaScript (Receiver):**
+**JavaScript (Sender/Receiver):**
 ```javascript
 // Receive NATS message with URL
 // Fetch data from HTTP server
@@ -448,42 +676,64 @@ async function smartreceive(msg, options = {})
 // Load into Perspective.js or D3
 ```
 
+**Python/Micropython (Sender/Receiver):**
+```python
+# Create large DataFrame
+# Convert to Arrow IPC stream
+# Check size (> 1MB)
+# Upload to HTTP server
+# Publish NATS with URL
+```
+
 ### Scenario 3: Live Audio Processing
 
-**JavaScript (Sender):**
+**JavaScript (Sender/Receiver):**
 ```javascript
 // Capture audio chunk
 // Send as binary with metadata headers
 // Use smartsend with type="audio"
 ```
 
-**Julia (Receiver):**
+**Julia (Sender/Receiver):**
 ```julia
-// Receive audio data
+# Receive audio data
-// Perform FFT or AI transcription
+# Perform FFT or AI transcription
-// Send results back (JSON + Arrow table)
+# Send results back (JSON + Arrow table)
+```
+
+**Python/Micropython (Sender/Receiver):**
+```python
+# Capture audio chunk
+# Send as binary with metadata headers
+# Use smartsend with type="audio"
 ```
 
 ### Scenario 4: Catch-Up (JetStream)
 
-**Julia (Producer):**
+**Julia (Producer/Consumer):**
 ```julia
 # Publish to JetStream
 # Include metadata for temporal tracking
 ```
 
-**JavaScript (Consumer):**
+**JavaScript (Producer/Consumer):**
 ```javascript
 // Connect to JetStream
 // Request replay from last 10 minutes
 // Process historical and real-time messages
 ```
 
+**Python/Micropython (Producer/Consumer):**
+```python
+# Publish to JetStream
+# Include metadata for temporal tracking
+```
+
 ### Scenario 5: Selection (Low Bandwidth)
 
-**Focus:** Small Arrow tables, Julia to JavaScript. The Action: Julia wants to send a small DataFrame to show on a JavaScript dashboard for the user to choose.
+**Focus:** Small Arrow tables, cross-platform communication. The Action: Any platform wants to send a small DataFrame to show on any receiving application for the user to choose.
 
-**Julia (Sender):**
+**Julia (Sender/Receiver):**
 ```julia
 # Create small DataFrame (e.g., 50KB - 500KB)
 # Convert to Arrow IPC stream
@@ -492,7 +742,7 @@ async function smartreceive(msg, options = {})
 # Include metadata for dashboard selection context
 ```
 
-**JavaScript (Receiver):**
+**JavaScript (Sender/Receiver):**
 ```javascript
 // Receive NATS message with direct transport
 // Decode Base64 payload
@@ -502,11 +752,20 @@ async function smartreceive(msg, options = {})
 // Send selection back to Julia
 ```
 
-**Use Case:** Julia server generates a list of available options (e.g., file selections, configuration presets) as a small DataFrame and sends to JavaScript dashboard for user selection. The selection is then sent back to Julia for processing.
+**Python/Micropython (Sender/Receiver):**
+```python
+# Create small DataFrame (e.g., 50KB - 500KB)
+# Convert to Arrow IPC stream
+# Check payload size (< 1MB threshold)
+# Publish directly to NATS with Base64-encoded payload
+# Include metadata for dashboard selection context
+```
+
+**Use Case:** Any server generates a list of available options (e.g., file selections, configuration presets) as a small DataFrame and sends to any receiving application for user selection. The selection is then sent back to the sender for processing.
 
 ### Scenario 6: Chat System
 
-**Focus:** Every conversational message is composed of any number and any combination of components, spanning the full spectrum from small to large. This includes text, images, audio, video, tables, and files—specifically accommodating everything from brief snippets to high-resolution images, large audio files, extensive tables, and massive documents. Support for claim-check delivery and full bi-directional messaging.
+**Focus:** Every conversational message is composed of any number and any combination of components, spanning the full spectrum from small to large. This includes text, images, audio, video, tables, and files—specifically accommodating everything from brief snippets to high-resolution images, large audio files, extensive tables, and massive documents. Support for claim-check delivery and full bi-directional messaging across all platforms.
 
 **Multi-Payload Support:** The system supports mixed-payload messages where a single message can contain multiple payloads with different transport strategies. The `smartreceive` function iterates through all payloads in the envelope and processes each according to its transport type.
 
@@ -545,7 +804,25 @@ async function smartreceive(msg, options = {})
 // Support bidirectional reply with claim-check delivery confirmation
 ```
 
-**Use Case:** Full-featured chat system supporting rich media. User can send text, small images directly, or upload large files that get uploaded to HTTP server and referenced via URLs. Claim-check pattern ensures reliable delivery tracking for all message components.
+**Python/Micropython (Sender/Receiver):**
+```python
+# Build chat message with mixed payloads:
+# - Text: direct transport (Base64)
+# - Small images: direct transport (Base64)
+# - Large images: link transport (HTTP URL)
+# - Audio/video: link transport (HTTP URL)
+# - Tables: direct or link depending on size
+# - Files: link transport (HTTP URL)
+# 
+# Each payload uses appropriate transport strategy:
+# - Size < 1MB → direct (NATS + Base64)
+# - Size >= 1MB → link (HTTP upload + NATS URL)
+# 
+# Include claim-check metadata for delivery tracking
+# Support bidirectional messaging with replyTo fields
+```
+
+**Use Case:** Full-featured chat system supporting rich media. User can send text, small images directly, or upload large files that get uploaded to HTTP server and referenced via URLs. Claim-check pattern ensures reliable delivery tracking for all message components across all platforms.
 
 **Implementation Note:** The `smartreceive` function iterates through all payloads in the envelope and processes each according to its transport type. See the standard API format in Section 1: `msgEnvelope_v1` supports `AbstractArray{msgPayload_v1}` for multiple payloads.
 

docs/implementation.md

@@ -2,74 +2,228 @@
 
 ## 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.
+This document describes the implementation of the high-performance, bi-directional data bridge between **Julia**, **JavaScript**, and **Python/Micropython** applications using NATS (Core & JetStream), implementing the Claim-Check pattern for large payloads.
 
-### Multi-Payload Support
+The system enables seamless communication across all three platforms:
+- **Julia ↔ JavaScript** bi-directional messaging
+- **JavaScript ↔ Python/Micropython** bi-directional messaging
+- **Julia ↔ Python/Micropython** bi-directional messaging (via JSON serialization)
 
-The implementation 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.**
+### Implementation Files
+
+NATSBridge is implemented in three languages, each providing the same API:
+
+| Language | Implementation File | Description |
+|----------|---------------------|-------------|
+| **Julia** | [`src/NATSBridge.jl`](../src/NATSBridge.jl) | Full Julia implementation with Arrow IPC support |
+| **JavaScript** | [`src/NATSBridge.js`](../src/NATSBridge.js) | JavaScript implementation for Node.js and browsers |
+| **Python/Micropython** | [`src/nats_bridge.py`](../src/nats_bridge.py) | Python implementation for desktop and microcontrollers |
+
+### 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:**
+
+```julia
+# Upload handler - uploads data to file server and returns URL
+# The handler is passed to smartsend as fileserver_upload_handler parameter
+# It receives: (file_server_url::String, dataname::String, data::Vector{UInt8})
+# Returns: Dict{String, Any} with keys: "status", "uploadid", "fileid", "url"
+fileserver_upload_handler(file_server_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
+
+# Download handler - fetches data from file server URL with exponential backoff
+# The handler is passed to smartreceive as fileserver_download_handler parameter
+# It receives: (url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)
+# Returns: Vector{UInt8} (the downloaded data)
+fileserver_download_handler(url::String, max_retries::Int, base_delay::Int, max_delay::Int, correlation_id::String)::Vector{UInt8}
+```
+
+This design allows the system to support multiple file server backends without changing the core messaging logic.
+
+### 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:**
 ```julia
 # 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 with type info)
+# Output format for smartreceive (returns a dictionary with payloads field containing list of tuples)
-[(dataname1, data1, type1), (dataname2, data2, type2), ...]
+# Returns: Dict with envelope metadata and payloads field containing Vector{Tuple{String, Any, String}}
+# {
+#   "correlation_id": "...",
+#   "msg_id": "...",
+#   "timestamp": "...",
+#   "send_to": "...",
+#   "msg_purpose": "...",
+#   "sender_name": "...",
+#   "sender_id": "...",
+#   "receiver_name": "...",
+#   "receiver_id": "...",
+#   "reply_to": "...",
+#   "reply_to_msg_id": "...",
+#   "broker_url": "...",
+#   "metadata": {...},
+#   "payloads": [(dataname1, data1, type1), (dataname2, data2, type2), ...]
+# }
 ```
 
-Where `type` can be: `"text"`, `"dictionary"`, `"table"`, `"image"`, `"audio"`, `"video"`, `"binary"`
+**Supported Types:**
+- `"text"` - Plain text
+- `"dictionary"` - JSON-serializable dictionaries (Dict, NamedTuple)
+- `"table"` - Tabular data (DataFrame, array of structs)
+- `"image"` - Image data (Bitmap, PNG/JPG bytes)
+- `"audio"` - Audio data (WAV, MP3 bytes)
+- `"video"` - Video data (MP4, AVI bytes)
+- `"binary"` - Generic binary data (Vector{UInt8})
+
+This design allows per-payload type specification, enabling **mixed-content messages** where different payloads can use different serialization formats in a single message.
 
 **Examples:**
 ```julia
-# Single payload - still wrapped in a list (type is required as third element)
+# Single payload - still wrapped in a list
-smartsend("/test", [(dataname1, data1, "text")], ...)
+smartsend(
+    "/test",
+    [("dataname1", data1, "dictionary")],  # List with one tuple (data, type)
+    broker_url="nats://localhost:4222",
+    fileserver_upload_handler=plik_oneshot_upload
+)
 
-# Multiple payloads in one message (each payload has its own type)
+# Multiple payloads in one message with different types
-smartsend("/test", [(dataname1, data1, "dictionary"), (dataname2, data2, "table")], ...)
+smartsend(
+    "/test",
+    [("dataname1", data1, "dictionary"), ("dataname2", data2, "table")],
+    broker_url="nats://localhost:4222",
+    fileserver_upload_handler=plik_oneshot_upload
+)
 
-# Receive always returns a list with type info
+# Mixed content (e.g., chat with text, image, audio)
-payloads = smartreceive(msg, ...)
+smartsend(
-# payloads = [(dataname1, data1, "text"), (dataname2, data2, "table"), ...]
+    "/chat",
+    [
+        ("message_text", "Hello!", "text"),
+        ("user_image", image_data, "image"),
+        ("audio_clip", audio_data, "audio")
+    ],
+    broker_url="nats://localhost:4222"
+)
+
+# Receive returns a dictionary envelope with all metadata and deserialized payloads
+env = smartreceive(msg; fileserver_download_handler=_fetch_with_backoff, max_retries=5, base_delay=100, max_delay=5000)
+# env["payloads"] = [("dataname1", data1, type1), ("dataname2", data2, type2), ...]
+# env["correlation_id"], env["msg_id"], etc.
+# env is a dictionary containing envelope metadata and payloads field
 ```
 
+## Cross-Platform Interoperability
+
+NATSBridge is designed for seamless communication between Julia, JavaScript, and Python/Micropython applications. All three implementations share the same interface and data format, ensuring compatibility across platforms.
+
+### Platform-Specific Features
+
+| Feature | Julia | JavaScript | Python/Micropython |
+|---------|-------|------------|-------------------|
+| Direct NATS transport | ✅ | ✅ | ✅ |
+| HTTP file server (Claim-Check) | ✅ | ✅ | ✅ |
+| Arrow IPC tables | ✅ | ✅ | ✅ |
+| Base64 encoding | ✅ | ✅ | ✅ |
+| Exponential backoff | ✅ | ✅ | ✅ |
+| Correlation ID tracking | ✅ | ✅ | ✅ |
+| Reply-to support | ✅ | ✅ | ✅ |
+
+### Data Type Mapping
+
+| Type | Julia | JavaScript | Python/Micropython |
+|------|-------|------------|-------------------|
+| `text` | `String` | `String` | `str` |
+| `dictionary` | `Dict` | `Object` | `dict` |
+| `table` | `DataFrame` | `Array<Object>` | `DataFrame` / `list` |
+| `image` | `Vector{UInt8}` | `ArrayBuffer/Uint8Array` | `bytes` |
+| `audio` | `Vector{UInt8}` | `ArrayBuffer/Uint8Array` | `bytes` |
+| `video` | `Vector{UInt8}` | `ArrayBuffer/Uint8Array` | `bytes` |
+| `binary` | `Vector{UInt8}` | `ArrayBuffer/Uint8Array` | `bytes` |
+
+### Example: Julia ↔ Python ↔ JavaScript
+
+```julia
+# Julia sender
+using NATSBridge
+data = [("message", "Hello from Julia!", "text")]
+smartsend("/cross_platform", data, broker_url="nats://localhost:4222")
+```
+
+```javascript
+// JavaScript receiver
+const { smartreceive } = require('./src/NATSBridge');
+const env = await smartreceive(msg);
+// env.payloads[0].data === "Hello from Julia!"
+```
+
+```python
+# Python sender
+from nats_bridge import smartsend
+data = [("response", "Hello from Python!", "text")]
+smartsend("/cross_platform", data, nats_url="nats://localhost:4222")
+```
+
+All three platforms can communicate seamlessly using the same NATS subjects and data format.
+
 ## Architecture
 
-The implementation follows the Claim-Check pattern:
+All three implementations (Julia, JavaScript, Python/Micropython) follow the same Claim-Check pattern:
 
 ```
 ┌─────────────────────────────────────────────────────────────────────────┐
 │                         SmartSend Function                              │
 └─────────────────────────────────────────────────────────────────────────┘
-                             │
+                              │
-                             ▼
+                              ▼
 ┌─────────────────────────────────────────────────────────────────────────┐
 │  Is payload size < 1MB?                                                 │
 └─────────────────────────────────────────────────────────────────────────┘
-                             │
+                              │
-           ┌─────────────────┴─────────────────┐
+            ┌─────────────────┴─────────────────┐
-           ▼                                   ▼
+            ▼                                   ▼
-     ┌─────────────────┐                 ┌─────────────────┐
+      ┌─────────────────┐                 ┌─────────────────┐
-     │  Direct Path    │                 │  Link Path      │
+      │  Direct Path    │                 │  Link Path      │
-     │  (< 1MB)        │                 │  (> 1MB)        │
+      │  (< 1MB)        │                 │  (> 1MB)        │
-     │                 │                 │                 │
+      │                 │                 │                 │
-     │ • Serialize to  │                 │ • Serialize to  │
+      │ • Serialize to  │                 │ • Serialize to  │
-     │   IOBuffer      │                 │   IOBuffer      │
+      │   Buffer        │                 │   Buffer        │
-     │ • Base64 encode │                 │ • Upload to     │
+      │ • Base64 encode │                 │ • Upload to     │
-     │ • Publish to    │                 │   HTTP Server   │
+      │ • Publish to    │                 │   HTTP Server   │
-     │   NATS          │                 │ • Publish to    │
+      │   NATS          │                 │ • Publish to    │
-     │                 │                 │   NATS with URL │
+      │                 │                 │   NATS with URL │
-     └─────────────────┘                 └─────────────────┘
+      └─────────────────┘                 └─────────────────┘
 ```
 
-## Files
+## smartsend Return Value
 
-### Julia Module: [`src/julia_bridge.jl`](../src/julia_bridge.jl)
+The `smartsend` function now returns a tuple containing both the envelope object and the JSON string representation:
+
+```julia
+env, env_json_str = smartsend(...)
+# env::msg_envelope_v1    - The envelope object with all metadata and payloads
+# env_json_str::String    - JSON string for publishing to NATS
+```
+
+**Options:**
+- `is_publish::Bool = true` - When `true` (default), the message is automatically published to NATS. When `false`, the function returns the envelope and JSON string without publishing, allowing manual publishing via NATS request-reply pattern.
+
+This enables two use cases:
+1. **Programmatic envelope access**: Access envelope fields directly via the `env` object
+2. **Direct JSON publishing**: Publish the JSON string directly using NATS request-reply pattern
+
+### Julia Module: [`src/NATSBridge.jl`](../src/NATSBridge.jl)
 
 The Julia implementation provides:
 
-- **[`MessageEnvelope`](../src/julia_bridge.jl)**: Struct for the unified JSON envelope
+- **[`msg_envelope_v1`](src/NATSBridge.jl)**: Struct for the unified JSON envelope
-- **[`SmartSend()`](../src/julia_bridge.jl)**: Handles transport selection based on payload size
+- **[`msg_payload_v1`](src/NATSBridge.jl)**: Struct for individual payload representation
-- **[`SmartReceive()`](../src/julia_bridge.jl)**: Handles both direct and link transport
+- **[`smartsend()`](src/NATSBridge.jl)**: Handles transport selection based on payload size
+- **[`smartreceive()`](src/NATSBridge.jl)**: Handles both direct and link transport
 
 ### JavaScript Module: [`src/NATSBridge.js`](../src/NATSBridge.js)
 
@@ -77,8 +231,17 @@ The JavaScript implementation provides:
 
 - **`MessageEnvelope` class**: For the unified JSON envelope
 - **`MessagePayload` class**: For individual payload representation
-- **[`smartsend()`](../src/NATSBridge.js)**: Handles transport selection based on payload size
+- **[`smartsend()`](src/NATSBridge.js)**: Handles transport selection based on payload size
-- **[`smartreceive()`](../src/NATSBridge.js)**: Handles both direct and link transport
+- **[`smartreceive()`](src/NATSBridge.js)**: Handles both direct and link transport
+
+### Python/Micropython Module: [`src/nats_bridge.py`](../src/nats_bridge.py)
+
+The Python/Micropython implementation provides:
+
+- **`MessageEnvelope` class**: For the unified JSON envelope
+- **`MessagePayload` class**: For individual payload representation
+- **[`smartsend()`](src/nats_bridge.py)**: Handles transport selection based on payload size
+- **[`smartreceive()`](src/nats_bridge.py)**: Handles both direct and link transport
 
 ## Installation
 
@@ -100,6 +263,23 @@ Pkg.add("Dates")
 npm install nats.js apache-arrow uuid base64-url
 ```
 
+### Python/Micropython Dependencies
+
+1. Copy [`src/nats_bridge.py`](../src/nats_bridge.py) to your device
+2. Ensure you have the following 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)
+   - `socket` for networking (built-in)
+   - `uuid` for UUID generation (built-in)
+
 ## Usage Tutorial
 
 ### Step 1: Start NATS Server
@@ -136,36 +316,79 @@ node test/scenario3_julia_to_julia.js
 
 ## Usage
 
-### Scenario 0: Basic Multi-Payload Example
+### Scenario 1: Command & Control (Small Dictionary)
 
-#### Julia (Sender)
+**Focus:** Sending small dictionary configurations across platforms. This is the simplest use case for command and control scenarios.
+
+**Julia (Sender/Receiver):**
 ```julia
 using NATSBridge
 
+# Subscribe to control subject
+# Parse JSON envelope
+# Execute simulation with parameters
+# Send acknowledgment
+```
+
+**JavaScript (Sender/Receiver):**
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Create small dictionary config
+// Send via smartsend with type="dictionary"
+const config = {
+    step_size: 0.01,
+    iterations: 1000,
+    threshold: 0.5
+};
+
+await smartsend("control", [
+    { dataname: "config", data: config, type: "dictionary" }
+]);
+```
+
+**Python/Micropython (Sender/Receiver):**
+```python
+from nats_bridge import smartsend
+
+# Create small dictionary config
+# Send via smartsend with type="dictionary"
+config = {
+    "step_size": 0.01,
+    "iterations": 1000,
+    "threshold": 0.5
+}
+
+smartsend("control", [("config", config, "dictionary")])
+```
+
+### Basic Multi-Payload Example
+
+#### Python/Micropython (Sender)
+```python
+from nats_bridge import smartsend
+
 # Send multiple payloads in one message (type is required per payload)
 smartsend(
     "/test",
     [("dataname1", data1, "dictionary"), ("dataname2", data2, "table")],
     nats_url="nats://localhost:4222",
-    fileserver_url="http://localhost:8080",
+    fileserver_url="http://localhost:8080"
-    metadata=Dict("custom_key" => "custom_value")
 )
 
 # Even single payload must be wrapped in a list with type
-smartsend("/test", [("single_data", mydata, "dictionary")])
+smartsend("/test", [("single_data", mydata, "dictionary")], nats_url="nats://localhost:4222")
 ```
 
-#### Julia (Receiver)
+#### Python/Micropython (Receiver)
-```julia
+```python
-using NATSBridge
+from nats_bridge import smartreceive
 
-# Receive returns a list of payloads with type info
+# Receive returns a dictionary with envelope metadata and payloads field
-payloads = smartreceive(msg, "http://localhost:8080")
+env = smartreceive(msg)
-# payloads = [(dataname1, data1, "dictionary"), (dataname2, data2, "table"), ...]
+# env["payloads"] = [(dataname1, data1, "dictionary"), (dataname2, data2, "table"), ...]
 ```
 
-### Scenario 1: Command & Control (Small JSON)
-
 #### JavaScript (Sender)
 ```javascript
 const { smartsend } = require('./src/NATSBridge');
@@ -198,27 +421,7 @@ const configs = [
 await smartsend("control", configs);
 ```
 
-#### Julia (Receiver)
+#### JavaScript (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
-```
-
-### JavaScript (Receiver)
 ```javascript
 const { smartreceive } = require('./src/NATSBridge');
 
@@ -227,13 +430,18 @@ const nc = await connect({ servers: ['nats://localhost:4222'] });
 const sub = nc.subscribe("control");
 
 for await (const msg of sub) {
-    const result = await smartreceive(msg);
+    const env = await smartreceive(msg);
     
-    // Process the result
+    // Process the payloads from the envelope
-    for (const { dataname, data, type } of result) {
+    for (const payload of env.payloads) {
+        const { dataname, data, type } = payload;
         console.log(`Received ${dataname} of type ${type}`);
         console.log(`Data: ${JSON.stringify(data)}`);
     }
+    
+    // Also access envelope metadata
+    console.log(`Correlation ID: ${env.correlation_id}`);
+    console.log(`Message ID: ${env.msg_id}`);
 }
 ```
 
@@ -251,23 +459,45 @@ df = DataFrame(
     category = rand(["A", "B", "C"], 10_000_000)
 )
 
-# Send via SmartSend - wrapped in a list (type is part of each tuple)
+# Send via smartsend - wrapped in a list (type is part of each tuple)
-await SmartSend("analysis_results", [("table_data", df, "table")]);
+env, env_json_str = smartsend("analysis_results", [("table_data", df, "table")], 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
 ```
 
 #### JavaScript (Receiver)
 ```javascript
 const { smartreceive } = require('./src/NATSBridge');
 
-const result = await smartreceive(msg);
+const env = await smartreceive(msg);
 
-// Use table data for visualization with Perspective.js or D3
+// Use table data from the payloads field
 // Note: Tables are sent as arrays of objects in JavaScript
-const table = result;
+const table = env.payloads;
 ```
 
 ### Scenario 3: Live Binary Processing
 
+#### Python/Micropython (Sender)
+```python
+from nats_bridge import smartsend
+
+# Binary data wrapped in a list
+binary_data = [
+    ("audio_chunk", binary_buffer, "binary")
+]
+
+smartsend(
+    "binary_input",
+    binary_data,
+    nats_url="nats://localhost:4222",
+    metadata={
+        "sample_rate": 44100,
+        "channels": 1
+    }
+)
+```
+
 #### JavaScript (Sender)
 ```javascript
 const { smartsend } = require('./src/NATSBridge');
@@ -287,35 +517,35 @@ await smartsend("binary_input", binaryData, {
 });
 ```
 
-#### Julia (Receiver)
+#### Python/Micropython (Receiver)
-```julia
+```python
-using WAV
+from nats_bridge import smartreceive
-using DSP
 
 # Receive binary data
-function process_binary(data)
+def process_binary(msg):
-    # Perform FFT or AI transcription
+    env = smartreceive(msg)
-    spectrum = fft(data)
     
-    # Send results back (JSON + Arrow table)
+    # Process the binary data from env.payloads
-    results = Dict("transcription" => "sample text", "spectrum" => spectrum)
+    for dataname, data, type in env["payloads"]:
-    await SmartSend("binary_output", results, "json")
+        if type == "binary":
-end
+            # data is bytes
+            print(f"Received binary data: {dataname}, size: {len(data)}")
+            # Perform FFT or AI transcription here
 ```
 
-### JavaScript (Receiver)
+#### JavaScript (Receiver)
 ```javascript
 const { smartreceive } = require('./src/NATSBridge');
 
 // Receive binary data
 function process_binary(msg) {
-    const result = await smartreceive(msg);
+    const env = await smartreceive(msg);
     
-    // Process the binary data
+    // Process the binary data from env.payloads
-    for (const { dataname, data, type } of result) {
+    for (const payload of env.payloads) {
-        if (type === "binary") {
+        if (payload.type === "binary") {
             // data is an ArrayBuffer or Uint8Array
-            console.log(`Received binary data: ${dataname}, size: ${data.length}`);
+            console.log(`Received binary data: ${payload.dataname}, size: ${payload.data.length}`);
             // Perform FFT or AI transcription here
         }
     }
@@ -331,7 +561,7 @@ using NATSBridge
 function publish_health_status(nats_url)
     # Send status wrapped in a list (type is part of each tuple)
     status = Dict("cpu" => rand(), "memory" => rand())
-    smartsend("health", [("status", status, "dictionary")], nats_url=nats_url)
+    smartsend("health", [("status", status, "dictionary")], broker_url=nats_url)
     sleep(5)  # Every 5 seconds
 end
 ```
@@ -353,13 +583,71 @@ const consumer = await js.pullSubscribe("health", {
 
 // Process historical and real-time messages
 for await (const msg of consumer) {
-    const result = await smartreceive(msg);
+    const env = await smartreceive(msg);
-    // result contains the list of payloads
+    // env.payloads contains the list of payloads
     // Each payload has: dataname, data, type
     msg.ack();
 }
 ```
 
+### Scenario 4: Micropython Device Control
+
+**Focus:** Sending configuration to a Micropython device over NATS. This demonstrates the lightweight nature of the Python implementation suitable for microcontrollers.
+
+**Python/Micropython (Receiver/Device):**
+```python
+from nats_bridge import smartsend, smartreceive
+import json
+
+# Device configuration handler
+def handle_device_config(msg):
+    env = smartreceive(msg)
+    
+    # Process configuration from payloads
+    for dataname, data, type in env["payloads"]:
+        if type == "dictionary":
+            print(f"Received configuration: {data}")
+            # Apply configuration to device
+            if "wifi_ssid" in data:
+                wifi_ssid = data["wifi_ssid"]
+                wifi_password = data["wifi_password"]
+                update_wifi_config(wifi_ssid, wifi_password)
+    
+    # Send confirmation back
+    config = {
+        "status": "configured",
+        "wifi_ssid": "MyNetwork",
+        "ip": get_device_ip()
+    }
+    smartsend(
+        "device/response",
+        [("config", config, "dictionary")],
+        nats_url="nats://localhost:4222",
+        reply_to=env.get("reply_to")
+    )
+```
+
+**JavaScript (Sender/Controller):**
+```javascript
+const { smartsend } = require('./src/NATSBridge');
+
+// Send configuration to Micropython device
+await smartsend("device/config", [
+    {
+        dataname: "config",
+        data: {
+            wifi_ssid: "MyNetwork",
+            wifi_password: "password123",
+            update_interval: 60,
+            temperature_threshold: 30.0
+        },
+        type: "dictionary"
+    }
+]);
+```
+
+**Use Case:** A controller sends WiFi and operational configuration to a Micropython device (e.g., ESP32). The device receives the configuration, applies it, and sends back a confirmation with its current status.
+
 ### Scenario 5: Selection (Low Bandwidth)
 
 **Focus:** Small Arrow tables, Julia to JavaScript. The Action: Julia wants to send a small DataFrame to show on a JavaScript dashboard for the user to choose.
@@ -395,11 +683,11 @@ smartsend(
 const { smartreceive, smartsend } = require('./src/NATSBridge');
 
 // Receive NATS message with direct transport
-const result = await smartreceive(msg);
+const env = await smartreceive(msg);
 
 // Decode Base64 payload (for direct transport)
-// For tables, data is an array of objects
+// For tables, data is in env.payloads
-const table = result;  // Array of objects
+const table = env.payloads;  // Array of objects
 
 // User makes selection
 const selection = uiComponent.getSelectedOption();
@@ -448,7 +736,7 @@ chat_message = [
 smartsend(
     "chat.room123",
     chat_message,
-    nats_url="nats://localhost:4222",
+    broker_url="nats://localhost:4222",
     msg_purpose="chat",
     reply_to="chat.room123.responses"
 )
@@ -496,7 +784,7 @@ await smartsend("chat.room123", message);
 
 **Use Case:** Full-featured chat system supporting rich media. User can send text, small images directly, or upload large files that get uploaded to HTTP server and referenced via URLs. Claim-check pattern ensures reliable delivery tracking for all message components.
 
-**Implementation Note:** The `smartreceive` function iterates through all payloads in the envelope and processes each according to its transport type. See the standard API format in Section 1: `msgEnvelope_v1` supports `AbstractArray{msgPayload_v1}` for multiple payloads.
+**Implementation Note:** The `smartreceive` function iterates through all payloads in the envelope and processes each according to its transport type. See the standard API format in Section 1: `msg_envelope_v1` supports `Vector{msg_payload_v1}` for multiple payloads.
 
 ## Configuration
 
@@ -512,19 +800,19 @@ await smartsend("chat.room123", message);
 
 ```json
 {
-  "correlationId": "uuid-v4-string",
+  "correlation_id": "uuid-v4-string",
-  "msgId": "uuid-v4-string",
+  "msg_id": "uuid-v4-string",
   "timestamp": "2024-01-15T10:30:00Z",
   
-  "sendTo": "topic/subject",
+  "send_to": "topic/subject",
-  "msgPurpose": "ACK | NACK | updateStatus | shutdown | chat",
+  "msg_purpose": "ACK | NACK | updateStatus | shutdown | chat",
-  "senderName": "agent-wine-web-frontend",
+  "sender_name": "agent-wine-web-frontend",
-  "senderId": "uuid4",
+  "sender_id": "uuid4",
-  "receiverName": "agent-backend",
+  "receiver_name": "agent-backend",
-  "receiverId": "uuid4",
+  "receiver_id": "uuid4",
-  "replyTo": "topic",
+  "reply_to": "topic",
-  "replyToMsgId": "uuid4",
+  "reply_to_msg_id": "uuid4",
-  "BrokerURL": "nats://localhost:4222",
+  "broker_url": "nats://localhost:4222",
   
   "metadata": {
     "content_type": "application/octet-stream",
@@ -535,7 +823,7 @@ await smartsend("chat.room123", message);
     {
       "id": "uuid4",
       "dataname": "login_image",
-      "type": "image",
+      "payload_type": "image",
       "transport": "direct",
       "encoding": "base64",
       "size": 15433,
@@ -558,7 +846,7 @@ await smartsend("chat.room123", message);
 ### Exponential Backoff
 - Maximum retry count: 5
 - Base delay: 100ms, max delay: 5000ms
-- Implemented in both Julia and JavaScript implementations
+- Implemented in all three implementations (Julia, JavaScript, Python/Micropython)
 
 ### Correlation ID Logging
 - Log correlation_id at every stage
@@ -567,14 +855,73 @@ await smartsend("chat.room123", message);
 
 ## Testing
 
-Run the test scripts:
+Run the test scripts for each platform:
+
+### Python/Micropython Tests
 
 ```bash
-# Scenario 1: Command & Control (JavaScript sender)
+# Basic functionality test
-node test/scenario1_command_control.js
+python test/test_micropython_basic.py
+```
 
-# Scenario 2: Large Arrow Table (JavaScript sender)
+### JavaScript Tests
-node test/scenario2_large_table.js
+
+```bash
+# Text message exchange
+node test/test_js_to_js_text_sender.js
+node test/test_js_to_js_text_receiver.js
+
+# Dictionary exchange
+node test/test_js_to_js_dict_sender.js
+node test/test_js_to_js_dict_receiver.js
+
+# File transfer (direct transport)
+node test/test_js_to_js_file_sender.js
+node test/test_js_to_js_file_receiver.js
+
+# Mixed payload types
+node test/test_js_to_js_mix_payloads_sender.js
+node test/test_js_to_js_mix_payloads_receiver.js
+
+# Table (Arrow IPC) exchange
+node test/test_js_to_js_table_sender.js
+node test/test_js_to_js_table_receiver.js
+```
+
+### Julia Tests
+
+```bash
+# Text message exchange
+julia test/test_julia_to_julia_text_sender.jl
+julia test/test_julia_to_julia_text_receiver.jl
+
+# Dictionary exchange
+julia test/test_julia_to_julia_dict_sender.jl
+julia test/test_julia_to_julia_dict_receiver.jl
+
+# File transfer
+julia test/test_julia_to_julia_file_sender.jl
+julia test/test_julia_to_julia_file_receiver.jl
+
+# Mixed payload types
+julia test/test_julia_to_julia_mix_payloads_sender.jl
+julia test/test_julia_to_julia_mix_payloads_receiver.jl
+
+# Table exchange
+julia test/test_julia_to_julia_table_sender.jl
+julia test/test_julia_to_julia_table_receiver.jl
+```
+
+### Cross-Platform Tests
+
+```bash
+# Julia ↔ JavaScript communication
+julia test/test_julia_to_julia_text_sender.jl
+node test/test_js_to_js_text_receiver.js
+
+# Python ↔ JavaScript communication
+python test/test_micropython_basic.py
+node test/test_js_to_js_text_receiver.js
 ```
 
 ## Troubleshooting
@@ -582,18 +929,24 @@ node test/scenario2_large_table.js
 ### Common Issues
 
 1. **NATS Connection Failed**
-   - Ensure NATS server is running
+   - **Julia/JavaScript/Python**: Ensure NATS server is running
-   - Check NATS_URL configuration
+   - **Python/Micropython**: Check `nats_url` parameter and network connectivity
 
 2. **HTTP Upload Failed**
    - Ensure file server is running
-   - Check FILESERVER_URL configuration
+   - Check `fileserver_url` configuration
    - Verify upload permissions
+   - **Micropython**: Ensure `urequests` is available and network is connected
 
 3. **Arrow IPC Deserialization Error**
    - Ensure data is properly serialized to Arrow format
    - Check Arrow version compatibility
 
+4. **Python/Micropython Specific Issues**
+   - **Import Error**: Ensure `nats_bridge.py` is in the correct path
+   - **Memory Error (Micropython)**: Reduce payload size or use link transport for large payloads
+   - **Unicode Error**: Ensure proper encoding when sending text data
+
 ## License
 
 MIT

etc.jl

@@ -1,21 +0,0 @@
-Check architecture.jl, NATSBridge.jl and its test files:
-- test_julia_to_julia_table_receiver.jl
-- test_julia_to_julia_table_sender.jl. 
-
-Now I want to test sending a mix-content message from Julia serviceA to Julia serviceB, for example, a chat system. 
-The test message must show that any combination and any number and any data size of text | json | table | image | audio | video | binary can be send and receive.
-
-Can you write me the following test files:
-- test_julia_to_julia_mix_receiver.jl
-- test_julia_to_julia_mix_sender.jl
-
-
-
-
-1. create a tutorial file "tutorial_julia.md" for NATSBridge.jl
-2. create a walkthrough file "walkthrough_julia.md" for NATSBridge.jl
-
-You may consult architecture.md for more info.
-
-
-

examples/tutorial.md

@@ -0,0 +1,620 @@
+# 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, nats_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, nats_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" }
+], { natsUrl: "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" }
+], { natsUrl: "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, nats_url="nats://localhost:4222")
+# env: msgEnvelope_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, nats_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" }
+]);
+```
+
+#### 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)
+```
+
+### 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, nats_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" }
+]);
+```
+
+#### 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)
+```
+
+### 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,
+    nats_url="nats://localhost:4222",
+    reply_to="/device/response",
+    reply_to_msg_id="cmd-001"
+)
+# env: msgEnvelope_v1 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")],
+    nats_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" }
+], {
+    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")],
+    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, nats_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"
+    }
+]);
+```
+
+#### 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)
+```
+
+### 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, nats_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)
+```
+
+---
+
+## 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, nats_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" }
+]);
+```
+
+#### 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)
+```
+
+#### Julia Receiver
+
+```julia
+using NATSBridge
+
+env = smartreceive(msg, fileserverDownloadHandler)
+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

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

@@ -460,8 +460,9 @@ async function smartsend(subject, data, options = {}) {
      * @param {string} options.receiverId - UUID of the receiver (default: "")
      * @param {string} options.replyTo - Topic to reply to (default: "")
      * @param {string} options.replyToMsgId - Message ID this message is replying to (default: "")
+     * @param {boolean} options.isPublish - Whether to automatically publish the message to NATS (default: true)
      * 
-     * @returns {Promise<MessageEnvelope>} - The envelope for tracking
+     * @returns {Promise<Object>} - An object with { env: MessageEnvelope, env_json_str: string }
      */
     const {
         natsUrl = DEFAULT_NATS_URL,
@@ -474,7 +475,8 @@ async function smartsend(subject, data, options = {}) {
         receiverName = "",
         receiverId = "",
         replyTo = "",
-        replyToMsgId = ""
+        replyToMsgId = "",
+        isPublish = true  // Whether to automatically publish the message to NATS
     } = options;
     
     log_trace(correlationId, `Starting smartsend for subject: ${subject}`);
@@ -556,10 +558,19 @@ async function smartsend(subject, data, options = {}) {
         payloads: payloads
     });
     
-    // Publish message to NATS
+    // Convert envelope to JSON string
-    await publish_message(natsUrl, subject, env.toString(), correlationId);
+    const env_json_str = env.toString();
     
-    return env;
+    // Publish to NATS if isPublish is true
+    if (isPublish) {
+        await publish_message(natsUrl, subject, env_json_str, correlationId);
+    }
+    
+    // Return both envelope and JSON string (tuple-like structure)
+    return {
+        env: env,
+        env_json_str: env_json_str
+    };
 }
 
 // Helper: Publish message to NATS
@@ -603,7 +614,7 @@ async function smartreceive(msg, options = {}) {
      * @param {number} options.baseDelay - Initial delay for exponential backoff in ms (default: 100)
      * @param {number} options.maxDelay - Maximum delay for exponential backoff in ms (default: 5000)
      * 
-     * @returns {Promise<Array>} - List of {dataname, data, type} objects
+     * @returns {Promise<Object>} - Envelope dictionary with metadata and payloads field containing list of {dataname, data, type} objects
      */
     const {
         fileserverDownloadHandler = _fetch_with_backoff,
@@ -664,7 +675,10 @@ async function smartreceive(msg, options = {}) {
         }
     }
     
-    return payloads_list;
+    // Replace payloads array with the processed list of {dataname, data, type} tuples
+    json_data.payloads = payloads_list;
+    
+    return json_data;
 }
 
 // Export for Node.js

src/nats_bridge.py

@@ -0,0 +1,672 @@
+"""
+Micropython NATS Bridge - Bi-Directional Data Bridge for Micropython
+
+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"
+"""
+
+import json
+import random
+import time
+import usocket
+import uselect
+import ustruct
+import uuid
+
+try:
+    import ussl
+    HAS_SSL = True
+except ImportError:
+    HAS_SSL = False
+
+# Constants
+DEFAULT_SIZE_THRESHOLD = 1000000  # 1MB - threshold for switching from direct to link transport
+DEFAULT_NATS_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."""
+    
+    def __init__(self, data, msg_type, id="", dataname="", transport="direct", 
+                 encoding="none", size=0, metadata=None):
+        """
+        Initialize a MessagePayload.
+        
+        Args:
+            data: Payload data (bytes for direct, URL string for link)
+            msg_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.type = msg_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,
+            "type": self.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."""
+        obj = {
+            "correlationId": self.correlation_id,
+            "msgId": self.msg_id,
+            "timestamp": self.timestamp,
+            "sendTo": self.send_to,
+            "msgPurpose": self.msg_purpose,
+            "senderName": self.sender_name,
+            "senderId": self.sender_id,
+            "receiverName": self.receiver_name,
+            "receiverId": self.receiver_id,
+            "replyTo": self.reply_to,
+            "replyToMsgId": self.reply_to_msg_id,
+            "brokerURL": 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, msg_type):
+    """Serialize data according to specified format.
+    
+    Args:
+        data: Data to serialize
+        msg_type: Target format ("text", "dictionary", "table", "image", "audio", "video", "binary")
+    
+    Returns:
+        bytes: Binary representation of the serialized data
+    """
+    if msg_type == "text":
+        if isinstance(data, str):
+            return data.encode('utf-8')
+        else:
+            raise ValueError("Text data must be a string")
+    
+    elif msg_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 msg_type in ("image", "audio", "video", "binary"):
+        if isinstance(data, bytes):
+            return data
+        else:
+            raise ValueError("{} data must be bytes".format(msg_type.capitalize()))
+    
+    else:
+        raise ValueError("Unknown type: {}".format(msg_type))
+
+
+def _deserialize_data(data_bytes, msg_type, correlation_id):
+    """Deserialize bytes to data based on type.
+    
+    Args:
+        data_bytes: Serialized data as bytes
+        msg_type: Data type ("text", "dictionary", "table", "image", "audio", "video", "binary")
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        Deserialized data
+    """
+    if msg_type == "text":
+        return data_bytes.decode('utf-8')
+    
+    elif msg_type == "dictionary":
+        json_str = data_bytes.decode('utf-8')
+        return json.loads(json_str)
+    
+    elif msg_type in ("image", "audio", "video", "binary"):
+        return data_bytes
+    
+    else:
+        raise ValueError("Unknown type: {}".format(msg_type))
+
+
+class NATSConnection:
+    """Simple NATS connection for Micropython."""
+    
+    def __init__(self, url=DEFAULT_NATS_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."""
+        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"
+        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.
+    
+    Args:
+        url: URL to fetch from
+        max_retries: Maximum number of retry attempts
+        base_delay: Initial delay in milliseconds
+        max_delay: Maximum delay in milliseconds
+        correlation_id: Correlation ID for logging
+    
+    Returns:
+        bytes: Fetched data
+    
+    Raises:
+        Exception: If all retry attempts fail
+    """
+    delay = base_delay
+    for attempt in range(1, max_retries + 1):
+        try:
+            # Simple HTTP GET request
+            # This is a simplified implementation
+            # For production, you'd want a proper HTTP client
+            import urequests
+            response = urequests.get(url)
+            if response.status_code == 200:
+                log_trace(correlation_id, "Successfully fetched data from {} on attempt {}".format(url, attempt))
+                return response.content
+            else:
+                raise Exception("Failed to fetch: {}".format(response.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)
+
+
+def plik_oneshot_upload(file_server_url, filename, data):
+    """Upload a single file to a plik server using one-shot mode.
+    
+    Args:
+        file_server_url: Base URL of the plik server
+        filename: 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
+    """
+    import urequests
+    import json
+    
+    # Get upload ID
+    url_get_upload_id = "{}/upload".format(file_server_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.content)
+    
+    uploadid = response_json.get("id")
+    uploadtoken = response_json.get("uploadToken")
+    
+    # Upload file
+    url_upload = "{}/file/{}".format(file_server_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(filename)
+    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.content)
+    
+    fileid = response_json.get("id")
+    url = "{}/file/{}/{}".format(file_server_url, uploadid, filename)
+    
+    return {
+        "status": response.status_code,
+        "uploadid": uploadid,
+        "fileid": fileid,
+        "url": url
+    }
+
+
+def smartsend(subject, data, nats_url=DEFAULT_NATS_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, type) tuples to send
+        nats_url: URL of the NATS server
+        fileserver_url: URL of the HTTP file server
+        fileserver_upload_handler: Function to handle fileserver uploads
+        size_threshold: Threshold in bytes separating direct vs link transport
+        correlation_id: Optional correlation ID for tracing
+        msg_purpose: Purpose of the message
+        sender_name: Name of the sender
+        receiver_name: Name of the receiver
+        receiver_id: UUID of the receiver
+        reply_to: Topic to reply to
+        reply_to_msg_id: Message ID this message is replying to
+        is_publish: Whether to automatically publish the message to NATS (default: True)
+    
+    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
+    """
+    # Generate correlation ID if not provided
+    cid = correlation_id if correlation_id 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 '{}' (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
+            payload_b64 = _serialize_data(payload_bytes, "binary")  # Already bytes
+            # Convert to base64 string for JSON
+            import ubinascii
+            payload_b64_str = ubinascii.b2a_base64(payload_bytes).decode('utf-8').strip()
+            
+            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["status"] != 200:
+                raise Exception("Failed to upload data to fileserver: {}".format(response["status"]))
+            
+            url = response["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=nats_url,
+        metadata={}
+    )
+    
+    msg_json = env.to_json()
+    
+    # Publish to NATS if is_publish is True
+    if is_publish:
+        nats_conn = NATSConnection(nats_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 with payload data)
+        fileserver_download_handler: Function to handle downloading data from file server URLs
+        max_retries: Maximum retry attempts for fetching URL
+        base_delay: Initial delay for exponential backoff in ms
+        max_delay: Maximum delay for exponential backoff in ms
+    
+    Returns:
+        dict: Envelope dictionary with metadata and 'payloads' field containing list of (dataname, data, type) tuples
+    """
+    # Parse the JSON envelope
+    json_data = msg if isinstance(msg, dict) else json.loads(msg)
+    log_trace(json_data.get("correlationId", ""), "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(json_data.get("correlationId", ""), 
+                     "Direct transport - decoding payload '{}'".format(dataname))
+            
+            # Extract base64 payload from the payload
+            payload_b64 = payload.get("data", "")
+            
+            # Decode Base64 payload
+            import ubinascii
+            payload_bytes = ubinascii.a2b_base64(payload_b64.encode('utf-8'))
+            
+            # Deserialize based on type
+            data_type = payload.get("type", "")
+            data = _deserialize_data(payload_bytes, data_type, json_data.get("correlationId", ""))
+            
+            payloads_list.append((dataname, data, data_type))
+            
+        elif transport == "link":
+            # Extract download URL from the payload
+            url = payload.get("data", "")
+            log_trace(json_data.get("correlationId", ""),
+                      "Link transport - fetching '{}' from URL: {}".format(dataname, url))
+            
+            # Fetch with exponential backoff
+            downloaded_data = fileserver_download_handler(
+                url, max_retries, base_delay, max_delay, json_data.get("correlationId", "")
+            )
+            
+            # Deserialize based on type
+            data_type = payload.get("type", "")
+            data = _deserialize_data(downloaded_data, data_type, json_data.get("correlationId", ""))
+            
+            payloads_list.append((dataname, data, data_type))
+            
+        else:
+            raise ValueError("Unknown transport type for payload '{}': {}".format(dataname, transport))
+    
+    # Replace payloads field with the processed list of (dataname, data, 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 for Micropython")
+    print("=========================")
+    print("This module provides:")
+    print("  - MessageEnvelope: Message envelope structure")
+    print("  - MessagePayload: Payload structure")
+    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("  data = [(\"message\", \"Hello World\", \"text\")]")
+    print("  env = smartsend(\"my.subject\", data)")
+    print()
+    print("  # On receiver:")
+    print("  payloads = smartreceive(msg)")
+    print("  for dataname, data, type in payloads:")
+    print("      print(f\"Received {dataname} of type {type}: {data}\")")

test/test_js_dict_receiver.js

@@ -37,8 +37,9 @@ async function test_dict_receive() {
             }
         );
         
-        // Result is a list of {dataname, data, type} objects
+        // Result is an envelope dictionary with payloads field
-        for (const { dataname, data, type } of result) {
+        // 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}`);
                 

test/test_js_dict_sender.js

@@ -118,7 +118,7 @@ async function test_dict_send() {
     // 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 = await smartsend(
+    const { env, env_json_str } = await smartsend(
         SUBJECT,
         [data1, data2],
         {
@@ -132,7 +132,8 @@ async function test_dict_send() {
             receiverName: "",
             receiverId: "",
             replyTo: "",
-            replyToMsgId: ""
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
         }
     );
     

test/test_js_file_receiver.js

@@ -36,8 +36,9 @@ async function test_large_binary_receive() {
             }
         );
         
-        // Result is a list of {dataname, data, type} objects
+        // Result is an envelope dictionary with payloads field
-        for (const { dataname, data, type } of result) {
+        // 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}`);

test/test_js_file_sender.js

@@ -98,7 +98,7 @@ async function test_large_binary_send() {
     
     // Use smartsend with binary type - will automatically use link transport
     // if file size exceeds the threshold (1MB by default)
-    const env = await smartsend(
+    const { env, env_json_str } = await smartsend(
         SUBJECT,
         [data1, data2],
         {
@@ -112,7 +112,8 @@ async function test_large_binary_send() {
             receiverName: "",
             receiverId: "",
             replyTo: "",
-            replyToMsgId: ""
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
         }
     );
     

test/test_js_mix_payload_sender.js

@@ -222,7 +222,7 @@ async function test_mix_send() {
     ];
     
     // Use smartsend with mixed content
-    const env = await smartsend(
+    const { env, env_json_str } = await smartsend(
         SUBJECT,
         payloads,
         {
@@ -236,7 +236,8 @@ async function test_mix_send() {
             receiverName: "",
             receiverId: "",
             replyTo: "",
-            replyToMsgId: ""
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
         }
     );
     

test/test_js_mix_payloads_receiver.js

@@ -40,10 +40,11 @@ async function test_mix_receive() {
             }
         );
         
-        log_trace(`Received ${result.length} payloads`);
+        log_trace(`Received ${result.payloads.length} payloads`);
         
-        // Result is a list of {dataname, data, type} objects
+        // Result is an envelope dictionary with payloads field
-        for (const { dataname, data, type } of result) {
+        // Access payloads with result.payloads
+        for (const { dataname, data, type } of result.payloads) {
             log_trace(`\n=== Payload: ${dataname} (type: ${type}) ===`);
             
             // Handle different data types
@@ -122,13 +123,13 @@ async function test_mix_receive() {
         
         // Summary
         console.log("\n=== Verification Summary ===");
-        const text_count = result.filter(x => x.type === "text").length;
+        const text_count = result.payloads.filter(x => x.type === "text").length;
-        const dict_count = result.filter(x => x.type === "dictionary").length;
+        const dict_count = result.payloads.filter(x => x.type === "dictionary").length;
-        const table_count = result.filter(x => x.type === "table").length;
+        const table_count = result.payloads.filter(x => x.type === "table").length;
-        const image_count = result.filter(x => x.type === "image").length;
+        const image_count = result.payloads.filter(x => x.type === "image").length;
-        const audio_count = result.filter(x => x.type === "audio").length;
+        const audio_count = result.payloads.filter(x => x.type === "audio").length;
-        const video_count = result.filter(x => x.type === "video").length;
+        const video_count = result.payloads.filter(x => x.type === "video").length;
-        const binary_count = result.filter(x => x.type === "binary").length;
+        const binary_count = result.payloads.filter(x => x.type === "binary").length;
         
         log_trace(`Text payloads: ${text_count}`);
         log_trace(`Dictionary payloads: ${dict_count}`);
@@ -140,7 +141,7 @@ async function test_mix_receive() {
         
         // Print transport type info for each payload if available
         console.log("\n=== Payload Details ===");
-        for (const { dataname, data, type } of result) {
+        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") {

test/test_js_table_receiver.js

@@ -40,8 +40,9 @@ async function test_table_receive() {
             }
         );
         
-        // Result is a list of {dataname, data, type} objects
+        // Result is an envelope dictionary with payloads field
-        for (const { dataname, data, type } of result) {
+        // 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}`);
                 

test/test_js_table_sender.js

@@ -118,7 +118,7 @@ async function test_table_send() {
     // 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 = await smartsend(
+    const { env, env_json_str } = await smartsend(
         SUBJECT,
         [data1, data2],
         {
@@ -132,7 +132,8 @@ async function test_table_send() {
             receiverName: "",
             receiverId: "",
             replyTo: "",
-            replyToMsgId: ""
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
         }
     );
     

test/test_js_text_receiver.js

@@ -37,8 +37,9 @@ async function test_text_receive() {
             }
         );
         
-        // Result is a list of {dataname, data, type} objects
+        // Result is an envelope dictionary with payloads field
-        for (const { dataname, data, type } of result) {
+        // 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`);

test/test_js_text_sender.js

@@ -94,7 +94,7 @@ async function test_text_send() {
     // 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 = await smartsend(
+    const { env, env_json_str } = await smartsend(
         SUBJECT,
         [data1, data2],
         {
@@ -108,7 +108,8 @@ async function test_text_send() {
             receiverName: "",
             receiverId: "",
             replyTo: "",
-            replyToMsgId: ""
+            replyToMsgId: "",
+            isPublish: true  // Publish the message to NATS
         }
     );
     

test/test_julia_dict_receiver.jl

@@ -42,8 +42,8 @@ function test_dict_receive()
             max_delay = 5000
         )
         
-        # Result is a list of (dataname, data, data_type) tuples
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
-        for (dataname, data, data_type) in result
+        for (dataname, data, data_type) in result["payloads"]
             if isa(data, JSON.Object{String, Any})
                 log_trace("Received Dictionary '$dataname' of type $data_type")
                 

test/test_julia_dict_sender.jl

@@ -92,12 +92,12 @@ function test_dict_send()
     # 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 = NATSBridge.smartsend(
+    env, env_json_str = NATSBridge.smartsend(
         SUBJECT,
-        [data1, data2],  # List of (dataname, data, type) tuples
+        [data1, data2];  # List of (dataname, data, type) tuples
-        nats_url = NATS_URL,
+        broker_url = NATS_URL,
         fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
+        fileserver_upload_handler = plik_upload_handler,
         size_threshold = 1_000_000,  # 1MB threshold
         correlation_id = correlation_id,
         msg_purpose = "chat",
@@ -105,7 +105,8 @@ function test_dict_send()
         receiver_name = "",
         receiver_id = "",
         reply_to = "",
-        reply_to_msg_id = ""
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
     )
     
     log_trace("Sent message with $(length(env.payloads)) payloads")
@@ -114,7 +115,7 @@ function test_dict_send()
     for (i, payload) in enumerate(env.payloads)
         log_trace("Payload $i ('$payload.dataname'):")
         log_trace("  Transport: $(payload.transport)")
-        log_trace("  Type: $(payload.type)")
+        log_trace("  Type: $(payload.payload_type)")
         log_trace("  Size: $(payload.size) bytes")
         log_trace("  Encoding: $(payload.encoding)")
         

test/test_julia_file_receiver.jl

@@ -44,8 +44,8 @@ function test_large_binary_receive()
             max_delay = 5000
         )
         
-        # Result is a list of (dataname, data) tuples
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
-        for (dataname, data, data_type) in result
+        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

test/test_julia_file_sender.jl

@@ -79,12 +79,12 @@ function test_large_binary_send()
     # 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 = NATSBridge.smartsend(
+    env, env_json_str = NATSBridge.smartsend(
         SUBJECT,
-        [data1, data2],  # List of (dataname, data, type) tuples
+        [data1, data2];  # List of (dataname, data, type) tuples
-        nats_url = NATS_URL;
+        broker_url = NATS_URL;
         fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
+        fileserver_upload_handler = plik_upload_handler,
         size_threshold = 1_000_000,
         correlation_id = correlation_id,
         msg_purpose = "chat",
@@ -92,11 +92,12 @@ function test_large_binary_send()
         receiver_name = "",
         receiver_id = "",
         reply_to = "",
-        reply_to_msg_id = ""
+        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].type)")
+    log_trace("Envelope type: $(env.payloads[1].payload_type)")
     
     # Check if link transport was used
     if env.payloads[1].transport == "link"

test/test_julia_mix_payloads_receiver.jl

@@ -45,10 +45,10 @@ function test_mix_receive()
             max_delay = 5000
         )
         
-        log_trace("Received $(length(result)) payloads")
+        log_trace("Received $(length(result["payloads"])) payloads")
         
-        # Result is a list of (dataname, data, data_type) tuples
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
-        for (dataname, data, data_type) in result
+        for (dataname, data, data_type) in result["payloads"]
             log_trace("\n=== Payload: $dataname (type: $data_type) ===")
             
             # Handle different data types
@@ -178,13 +178,13 @@ function test_mix_receive()
         
         # Summary
         println("\n=== Verification Summary ===")
-        text_count = count(x -> x[3] == "text", result)
+        text_count = count(x -> x[3] == "text", result["payloads"])
-        dict_count = count(x -> x[3] == "dictionary", result)
+        dict_count = count(x -> x[3] == "dictionary", result["payloads"])
-        table_count = count(x -> x[3] == "table", result)
+        table_count = count(x -> x[3] == "table", result["payloads"])
-        image_count = count(x -> x[3] == "image", result)
+        image_count = count(x -> x[3] == "image", result["payloads"])
-        audio_count = count(x -> x[3] == "audio", result)
+        audio_count = count(x -> x[3] == "audio", result["payloads"])
-        video_count = count(x -> x[3] == "video", result)
+        video_count = count(x -> x[3] == "video", result["payloads"])
-        binary_count = count(x -> x[3] == "binary", result)
+        binary_count = count(x -> x[3] == "binary", result["payloads"])
         
         log_trace("Text payloads: $text_count")
         log_trace("Dictionary payloads: $dict_count")
@@ -196,7 +196,7 @@ function test_mix_receive()
         
         # Print transport type info for each payload if available
         println("\n=== Payload Details ===")
-        for (dataname, data, data_type) in result
+        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"

test/test_julia_mix_payloads_sender.jl

@@ -186,12 +186,12 @@ function test_mix_send()
     ]
     
     # Use smartsend with mixed content
-    env = NATSBridge.smartsend(
+    env, env_json_str = NATSBridge.smartsend(
         SUBJECT,
-        payloads,  # List of (dataname, data, type) tuples
+        payloads;  # List of (dataname, data, type) tuples
-        nats_url = NATS_URL,
+        broker_url = NATS_URL,
         fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
+        fileserver_upload_handler = plik_upload_handler,
         size_threshold = 1_000_000,  # 1MB threshold
         correlation_id = correlation_id,
         msg_purpose = "chat",
@@ -199,7 +199,8 @@ function test_mix_send()
         receiver_name = "",
         receiver_id = "",
         reply_to = "",
-        reply_to_msg_id = ""
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
     )
     
     log_trace("Sent message with $(length(env.payloads)) payloads")
@@ -208,7 +209,7 @@ function test_mix_send()
     for (i, payload) in enumerate(env.payloads)
         log_trace("Payload $i ('$payload.dataname'):")
         log_trace("  Transport: $(payload.transport)")
-        log_trace("  Type: $(payload.type)")
+        log_trace("  Type: $(payload.payload_type)")
         log_trace("  Size: $(payload.size) bytes")
         log_trace("  Encoding: $(payload.encoding)")
         

test/test_julia_table_receiver.jl

@@ -42,8 +42,8 @@ function test_table_receive()
             max_delay = 5000
         )
         
-        # Result is a list of (dataname, data, data_type) tuples
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
-        for (dataname, data, data_type) in result
+        for (dataname, data, data_type) in result["payloads"]
           data = DataFrame(data)
             if isa(data, DataFrame)
                 log_trace("Received DataFrame '$dataname' of type $data_type")

test/test_julia_table_sender.jl

@@ -90,12 +90,12 @@ function test_table_send()
     # 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 = NATSBridge.smartsend(
+    env, env_json_str = NATSBridge.smartsend(
         SUBJECT,
-        [data1, data2],  # List of (dataname, data, type) tuples
+        [data1, data2];  # List of (dataname, data, type) tuples
-        nats_url = NATS_URL,
+        broker_url = NATS_URL,
         fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
+        fileserver_upload_handler = plik_upload_handler,
         size_threshold = 1_000_000,  # 1MB threshold
         correlation_id = correlation_id,
         msg_purpose = "chat",
@@ -103,7 +103,8 @@ function test_table_send()
         receiver_name = "",
         receiver_id = "",
         reply_to = "",
-        reply_to_msg_id = ""
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
     )
     
     log_trace("Sent message with $(length(env.payloads)) payloads")
@@ -112,7 +113,7 @@ function test_table_send()
     for (i, payload) in enumerate(env.payloads)
         log_trace("Payload $i ('$payload.dataname'):")
         log_trace("  Transport: $(payload.transport)")
-        log_trace("  Type: $(payload.type)")
+        log_trace("  Type: $(payload.payload_type)")
         log_trace("  Size: $(payload.size) bytes")
         log_trace("  Encoding: $(payload.encoding)")
         

test/test_julia_text_receiver.jl

@@ -42,8 +42,8 @@ function test_text_receive()
             max_delay = 5000
         )
         
-        # Result is a list of (dataname, data, data_type) tuples
+        # Result is an envelope dictionary with payloads field containing list of (dataname, data, data_type) tuples
-        for (dataname, data, data_type) in result
+        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")

test/test_julia_text_sender.jl

@@ -75,12 +75,12 @@ function test_text_send()
     # 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 = NATSBridge.smartsend(
+    env, env_json_str = NATSBridge.smartsend(
         SUBJECT,
-        [data1, data2],  # List of (dataname, data, type) tuples
+        [data1, data2];  # List of (dataname, data, type) tuples
-        nats_url = NATS_URL,
+        broker_url = NATS_URL,
         fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
+        fileserver_upload_handler = plik_upload_handler,
         size_threshold = 1_000_000,  # 1MB threshold
         correlation_id = correlation_id,
         msg_purpose = "chat",
@@ -88,7 +88,8 @@ function test_text_send()
         receiver_name = "",
         receiver_id = "",
         reply_to = "",
-        reply_to_msg_id = ""
+        reply_to_msg_id = "",
+        is_publish = true  # Publish the message to NATS
     )
     
     log_trace("Sent message with $(length(env.payloads)) payloads")
@@ -97,7 +98,7 @@ function test_text_send()
     for (i, payload) in enumerate(env.payloads)
         log_trace("Payload $i ('$payload.dataname'):")
         log_trace("  Transport: $(payload.transport)")
-        log_trace("  Type: $(payload.type)")
+        log_trace("  Type: $(payload.payload_type)")
         log_trace("  Size: $(payload.size) bytes")
         log_trace("  Encoding: $(payload.encoding)")
         

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()

tutorial_julia.md

@@ -1,634 +0,0 @@
-# NATSBridge.jl Tutorial
-
-A comprehensive tutorial for learning how to use NATSBridge.jl for bi-directional communication between Julia and JavaScript services using NATS.
-
-## Table of Contents
-
-1. [What is NATSBridge.jl?](#what-is-natsbridgejl)
-2. [Key Concepts](#key-concepts)
-3. [Installation](#installation)
-4. [Basic Usage](#basic-usage)
-5. [Payload Types](#payload-types)
-6. [Transport Strategies](#transport-strategies)
-7. [Advanced Features](#advanced-features)
-8. [Complete Examples](#complete-examples)
-
----
-
-## What is NATSBridge.jl?
-
-NATSBridge.jl is a Julia module that provides a high-level API for sending and receiving data across network boundaries using NATS as the message bus. It implements the **Claim-Check pattern** for handling large payloads efficiently.
-
-### Core Features
-
-- **Bi-directional communication**: Julia ↔ JavaScript
-- **Smart transport selection**: Automatic direct vs link transport based on payload size
-- **Multi-payload support**: Send multiple payloads of different types in a single message
-- **Claim-check pattern**: Upload large files to HTTP server, send only URLs via NATS
-- **Type-aware serialization**: Different serialization strategies for different data types
-
----
-
-## Key Concepts
-
-### 1. msgEnvelope_v1 (Message Envelope)
-
-The `msgEnvelope_v1` structure provides a comprehensive message format for bidirectional communication:
-
-```julia
-struct msgEnvelope_v1
-  correlationId::String       # Unique identifier to track messages
-  msgId::String               # This message id
-  timestamp::String           # Message published timestamp
-  
-  sendTo::String              # Topic/subject the sender sends to
-  msgPurpose::String          # Purpose (ACK | NACK | updateStatus | shutdown | chat)
-  senderName::String          # Sender name (e.g., "agent-wine-web-frontend")
-  senderId::String            # Sender id (uuid4)
-  receiverName::String        # Message receiver name (e.g., "agent-backend")
-  receiverId::String          # Message receiver id (uuid4 or nothing for broadcast)
-  replyTo::String             # Topic to reply to
-  replyToMsgId::String        # Message id this message is replying to
-  brokerURL::String           # NATS server address
-  
-  metadata::Dict{String, Any}
-  payloads::AbstractArray{msgPayload_v1}  # Multiple payloads stored here
-end
-```
-
-### 2. msgPayload_v1 (Payload Structure)
-
-The `msgPayload_v1` structure provides flexible payload handling:
-
-```julia
-struct msgPayload_v1
-  id::String                    # Id of this payload (e.g., "uuid4")
-  dataname::String              # Name of this payload (e.g., "login_image")
-  type::String                  # "text | dictionary | table | image | audio | video | binary"
-  transport::String             # "direct | link"
-  encoding::String              # "none | json | base64 | arrow-ipc"
-  size::Integer                 # Data size in bytes
-  data::Any                     # Payload data in case of direct transport or a URL in case of link
-  metadata::Dict{String, Any}   # Dict("checksum" => "sha256_hash", ...)
-end
-```
-
-### 3. Standard API Format
-
-The system uses a **standardized list-of-tuples format** for all payload operations:
-
-```julia
-# 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), ...]
-```
-
-**Important**: Even when sending a single payload, you must wrap it in a list.
-
----
-
-## Installation
-
-```julia
-using Pkg
-Pkg.add("NATS")
-Pkg.add("JSON")
-Pkg.add("Arrow")
-Pkg.add("HTTP")
-Pkg.add("UUIDs")
-Pkg.add("Dates")
-Pkg.add("Base64")
-Pkg.add("PrettyPrinting")
-Pkg.add("DataFrames")
-```
-
-Then include the NATSBridge module:
-
-```julia
-include("NATSBridge.jl")
-using .NATSBridge
-```
-
----
-
-## Basic Usage
-
-### Sending Data (smartsend)
-
-```julia
-using NATSBridge
-
-# Send a simple dictionary
-data = Dict("key" => "value")
-env = NATSBridge.smartsend("my.subject", [("dataname1", data, "dictionary")])
-```
-
-### Receiving Data (smartreceive)
-
-```julia
-using NATSBridge
-
-# Subscribe to a NATS subject
-NATS.subscribe("my.subject") do msg
-    # Process the message
-    result = NATSBridge.smartreceive(
-        msg,
-        max_retries = 5,
-        base_delay = 100,
-        max_delay = 5000
-    )
-    
-    # result is a list of (dataname, data, type) tuples
-    for (dataname, data, type) in result
-        println("Received $dataname of type $type")
-        println("Data: $data")
-    end
-end
-```
-
----
-
-## Payload Types
-
-NATSBridge.jl supports the following payload types:
-
-| Type | Description | Serialization |
-|------|-------------|---------------|
-| `text` | Plain text | UTF-8 encoding |
-| `dictionary` | JSON-serializable data (Dict, NamedTuple) | JSON |
-| `table` | Tabular data (DataFrame, array of structs) | Apache Arrow IPC |
-| `image` | Image data (Bitmap, PNG/JPG bytes) | Binary |
-| `audio` | Audio data (WAV, MP3 bytes) | Binary |
-| `video` | Video data (MP4, AVI bytes) | Binary |
-| `binary` | Generic binary data | Binary |
-
----
-
-## Transport Strategies
-
-NATSBridge.jl automatically selects the appropriate transport strategy based on payload size:
-
-### Direct Transport (< 1MB)
-
-Small payloads are encoded as Base64 and sent directly over NATS.
-
-```julia
-# Small data (< 1MB) - uses direct transport
-small_data = rand(1000)  # ~8KB
-env = NATSBridge.smartsend("small", [("data", small_data, "table")])
-```
-
-### Link Transport (≥ 1MB)
-
-Large payloads are uploaded to an HTTP file server, and only the URL is sent via NATS.
-
-```julia
-# Large data (≥ 1MB) - uses link transport
-large_data = rand(10_000_000)  # ~80MB
-env = NATSBridge.smartsend("large", [("data", large_data, "table")])
-```
-
----
-
-## Complete Examples
-
-### Example 1: Text Message
-
-**Sender:**
-```julia
-using NATSBridge
-using UUIDs
-
-const SUBJECT = "/NATSBridge_text_test"
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function test_text_send()
-    small_text = "Hello, this is a small text message."
-    large_text = join(["Line $i: " for i in 1:50000], "")
-    
-    data1 = ("small_text", small_text, "text")
-    data2 = ("large_text", large_text, "text")
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [data1, data2],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "text_sender"
-    )
-end
-```
-
-**Receiver:**
-```julia
-using NATSBridge
-
-const SUBJECT = "/NATSBridge_text_test"
-const NATS_URL = "nats://localhost:4222"
-
-function test_text_receive()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        result = NATSBridge.smartreceive(
-            msg,
-            max_retries = 5,
-            base_delay = 100,
-            max_delay = 5000
-        )
-        
-        for (dataname, data, data_type) in result
-            if data_type == "text"
-                println("Received text: $data")
-                write("./received_$dataname.txt", data)
-            end
-        end
-    end
-    sleep(120)
-    NATS.drain(conn)
-end
-```
-
-### Example 2: Dictionary (JSON) Message
-
-**Sender:**
-```julia
-using NATSBridge
-using UUIDs
-
-const SUBJECT = "/NATSBridge_dict_test"
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$fileserver_url/upload"
-    headers = ["Content-Type" => "application/json"]
-    body = """{ "OneShot" : true }"""
-    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
-    responseJson = JSON.parse(String(httpResponse.body))
-    uploadid = responseJson["id"]
-    uploadtoken = responseJson["uploadToken"]
-    
-    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
-    url_upload = "$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/$dataname"
-    
-    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
-end
-
-function test_dict_send()
-    small_dict = Dict("name" => "Alice", "age" => 30)
-    large_dict = Dict("ids" => collect(1:50000), "names" => ["User_$i" for i in 1:50000])
-    
-    data1 = ("small_dict", small_dict, "dictionary")
-    data2 = ("large_dict", large_dict, "dictionary")
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [data1, data2],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat"
-    )
-end
-```
-
-**Receiver:**
-```julia
-using NATSBridge
-
-const SUBJECT = "/NATSBridge_dict_test"
-const NATS_URL = "nats://localhost:4222"
-
-function test_dict_receive()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        result = NATSBridge.smartreceive(
-            msg,
-            max_retries = 5,
-            base_delay = 100,
-            max_delay = 5000
-        )
-        
-        for (dataname, data, data_type) in result
-            if data_type == "dictionary"
-                println("Received dictionary: $data")
-                write("./received_$dataname.json", JSON.json(data, 2))
-            end
-        end
-    end
-    sleep(120)
-    NATS.drain(conn)
-end
-```
-
-### Example 3: DataFrame (Table) Message
-
-**Sender:**
-```julia
-using NATSBridge
-using DataFrames
-using UUIDs
-
-const SUBJECT = "/NATSBridge_table_test"
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$fileserver_url/upload"
-    headers = ["Content-Type" => "application/json"]
-    body = """{ "OneShot" : true }"""
-    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
-    responseJson = JSON.parse(String(httpResponse.body))
-    uploadid = responseJson["id"]
-    uploadtoken = responseJson["uploadToken"]
-    
-    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
-    url_upload = "$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/$dataname"
-    
-    return Dict("status" => httpResponse.status, "uploadid" => uploadid, "fileid" => fileid, "url" => url)
-end
-
-function test_table_send()
-    small_df = DataFrame(id = 1:10, name = ["Alice", "Bob", "Charlie"], score = [95, 88, 92])
-    large_df = DataFrame(id = 1:50000, name = ["User_$i" for i in 1:50000], score = rand(1:100, 50000))
-    
-    data1 = ("small_table", small_df, "table")
-    data2 = ("large_table", large_df, "table")
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [data1, data2],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat"
-    )
-end
-```
-
-**Receiver:**
-```julia
-using NATSBridge
-using DataFrames
-
-const SUBJECT = "/NATSBridge_table_test"
-const NATS_URL = "nats://localhost:4222"
-
-function test_table_receive()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        result = NATSBridge.smartreceive(
-            msg,
-            max_retries = 5,
-            base_delay = 100,
-            max_delay = 5000
-        )
-        
-        for (dataname, data, data_type) in result
-            if data_type == "table"
-                data = DataFrame(data)
-                println("Received DataFrame with $(size(data, 1)) rows")
-                display(data[1:min(5, size(data, 1)), :])
-            end
-        end
-    end
-    sleep(120)
-    NATS.drain(conn)
-end
-```
-
-### Example 4: Mixed Content (Chat with Text, Image, Audio)
-
-**Sender:**
-```julia
-using NATSBridge
-using DataFrames
-using UUIDs
-
-const SUBJECT = "/NATSBridge_mix_test"
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function test_mix_send()
-    # Text data
-    text_data = "Hello! This is a test chat message. 🎉"
-    
-    # Dictionary data
-    dict_data = Dict("type" => "chat", "sender" => "serviceA")
-    
-    # Small table data
-    table_data_small = DataFrame(id = 1:10, name = ["msg_$i" for i in 1:10])
-    
-    # Large table data (link transport)
-    table_data_large = DataFrame(id = 1:150_000, name = ["msg_$i" for i in 1:150_000])
-    
-    # Small image data (direct transport)
-    image_data = UInt8[rand(1:255) for _ in 1:100]
-    
-    # Large image data (link transport)
-    large_image_data = UInt8[rand(1:255) for _ in 1:1_500_000]
-    
-    # Small audio data (direct transport)
-    audio_data = UInt8[rand(1:255) for _ in 1:100]
-    
-    # Large audio data (link transport)
-    large_audio_data = UInt8[rand(1:255) for _ in 1:1_500_000]
-    
-    # Small video data (direct transport)
-    video_data = UInt8[rand(1:255) for _ in 1:150]
-    
-    # Large video data (link transport)
-    large_video_data = UInt8[rand(1:255) for _ in 1:1_500_000]
-    
-    # Small binary data (direct transport)
-    binary_data = UInt8[rand(1:255) for _ in 1:200]
-    
-    # Large binary data (link transport)
-    large_binary_data = UInt8[rand(1:255) for _ in 1:1_500_000]
-    
-    # Create payloads list - mixed content
-    payloads = [
-        # Small data (direct transport)
-        ("chat_text", text_data, "text"),
-        ("chat_json", dict_data, "dictionary"),
-        ("chat_table_small", table_data_small, "table"),
-        
-        # Large data (link transport)
-        ("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")
-    ]
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        payloads,
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "mix_sender"
-    )
-end
-```
-
-**Receiver:**
-```julia
-using NATSBridge
-using DataFrames
-
-const SUBJECT = "/NATSBridge_mix_test"
-const NATS_URL = "nats://localhost:4222"
-
-function test_mix_receive()
-    conn = NATS.connect(NATS_URL)
-    NATS.subscribe(conn, SUBJECT) do msg
-        result = NATSBridge.smartreceive(
-            msg,
-            max_retries = 5,
-            base_delay = 100,
-            max_delay = 5000
-        )
-        
-        println("Received $(length(result)) payloads")
-        
-        for (dataname, data, data_type) in result
-            println("\n=== Payload: $dataname (type: $data_type) ===")
-            
-            if data_type == "text"
-                println("  Type: String")
-                println("  Length: $(length(data)) characters")
-                
-            elseif data_type == "dictionary"
-                println("  Type: JSON Object")
-                println("  Keys: $(keys(data))")
-                
-            elseif data_type == "table"
-                data = DataFrame(data)
-                println("  Type: DataFrame")
-                println("  Dimensions: $(size(data, 1)) rows x $(size(data, 2)) columns")
-                
-            elseif data_type == "image"
-                println("  Type: Vector{UInt8}")
-                println("  Size: $(length(data)) bytes")
-                write("./received_$dataname.bin", data)
-                
-            elseif data_type == "audio"
-                println("  Type: Vector{UInt8}")
-                println("  Size: $(length(data)) bytes")
-                write("./received_$dataname.bin", data)
-                
-            elseif data_type == "video"
-                println("  Type: Vector{UInt8}")
-                println("  Size: $(length(data)) bytes")
-                write("./received_$dataname.bin", data)
-                
-            elseif data_type == "binary"
-                println("  Type: Vector{UInt8}")
-                println("  Size: $(length(data)) bytes")
-                write("./received_$dataname.bin", data)
-            end
-        end
-    end
-    sleep(120)
-    NATS.drain(conn)
-end
-```
-
----
-
-## Best Practices
-
-1. **Always wrap payloads in a list** - Even for single payloads: `[("dataname", data, "type")]`
-2. **Use appropriate transport** - Let NATSBridge handle size-based routing (default 1MB threshold)
-3. **Customize size threshold** - Use `size_threshold` parameter to adjust the direct/link split
-4. **Provide fileserver handler** - Implement `fileserverUploadHandler` for link transport
-5. **Include correlation IDs** - Track messages across distributed systems
-6. **Handle errors** - Implement proper error handling for network failures
-7. **Close connections** - Ensure NATS connections are properly closed using `NATS.drain()`
-
----
-
-## Conclusion
-
-NATSBridge.jl provides a powerful abstraction for bi-directional communication between Julia and JavaScript services. By understanding the key concepts and following the best practices, you can build robust, scalable applications that leverage the full power of NATS messaging.
-
-For more information, see:
-- [`docs/architecture.md`](./architecture.md) - Detailed architecture documentation
-- [`docs/implementation.md`](./implementation.md) - Implementation details

walkthrough_julia.md

@@ -1,939 +0,0 @@
-# NATSBridge.jl Walkthrough: Building a Chat System
-
-A step-by-step guided walkthrough for building a real-time chat system using NATSBridge.jl with mixed content support (text, images, audio, video, and files).
-
-## Prerequisites
-
-- Julia 1.7+
-- NATS server running
-- HTTP file server (Plik) running
-
-## Step 1: Understanding the Chat System Architecture
-
-### System Components
-
-```
-┌─────────────────────────────────────────────────────────────────────────────┐
-│                              Chat System                                   │
-├─────────────────────────────────────────────────────────────────────────────┤
-│                                                                            │
-│  ┌──────────────┐        NATS         ┌──────────────┐                     │
-│  │   Julia      │◄───────┬───────►   │   JavaScript │                     │
-│  │  Service     │        │          │   Client     │                     │
-│  │              │        │          │              │                     │
-│  │ - Text       │        │          │ - Text       │                     │
-│  │ - Images     │        │          │ - Images     │                     │
-│  │ - Audio      │        ▼          │ - Audio      │                     │
-│  │ - Video      │  NATSBridge.jl    │ - Files      │                     │
-│  │ - Files      │        │          │ - Tables     │                     │
-│  └──────────────┘        │          └──────────────┘                     │
-│                          │                                                 │
-│                  ┌───────┴───────┐                                         │
-│                  │   NATS      │                                         │
-│                  │   Server    │                                         │
-│                  └─────────────┘                                         │
-│                                                                            │
-└─────────────────────────────────────────────────────────────────────────────┘
-
-For large payloads (> 1MB):
-┌─────────────────────────────────────────────────────────────────────────────┐
-│                           File Server (Plik)                               │
-│                                                                            │
-│  Julia Service ──► Upload ──► File Server ──► Download ◄── JavaScript Client│
-│                                                                            │
-└─────────────────────────────────────────────────────────────────────────────┘
-```
-
-### Message Format
-
-Each chat message is an envelope containing multiple payloads:
-
-```json
-{
-  "correlationId": "uuid4",
-  "msgId": "uuid4",
-  "timestamp": "2024-01-15T10:30:00Z",
-  "sendTo": "/chat/room1",
-  "msgPurpose": "chat",
-  "senderName": "user-1",
-  "senderId": "uuid4",
-  "receiverName": "user-2",
-  "receiverId": "uuid4",
-  "brokerURL": "nats://localhost:4222",
-  "payloads": [
-    {
-      "id": "uuid4",
-      "dataname": "message_text",
-      "type": "text",
-      "transport": "direct",
-      "encoding": "base64",
-      "size": 256,
-      "data": "SGVsbG8gV29ybGQh",
-      "metadata": {}
-    },
-    {
-      "id": "uuid4",
-      "dataname": "user_image",
-      "type": "image",
-      "transport": "link",
-      "encoding": "none",
-      "size": 15433,
-      "data": "http://localhost:8080/file/UPLOAD_ID/FILE_ID/image.jpg",
-      "metadata": {}
-    }
-  ]
-}
-```
-
-## Step 2: Setting Up the Environment
-
-### 1. Start NATS Server
-
-```bash
-# Using Docker
-docker run -d -p 4222:4222 -p 8222:8222 --name nats-server nats:latest
-
-# Or download from https://github.com/nats-io/nats-server/releases
-./nats-server
-```
-
-### 2. Start HTTP File Server (Plik)
-
-```bash
-# Using Docker
-docker run -d -p 8080:8080 --name plik plik/plik:latest
-
-# Or download from https://github.com/arnaud-lb/plik/releases
-./plikd -d
-```
-
-### 3. Install Julia Dependencies
-
-```julia
-using Pkg
-Pkg.add("NATS")
-Pkg.add("JSON")
-Pkg.add("Arrow")
-Pkg.add("HTTP")
-Pkg.add("UUIDs")
-Pkg.add("Dates")
-Pkg.add("Base64")
-Pkg.add("PrettyPrinting")
-Pkg.add("DataFrames")
-```
-
-## Step 3: Basic Text-Only Chat
-
-### Sender (User 1)
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-# Include the bridge module
-include("NATSBridge.jl")
-using .NATSBridge
-
-# Configuration
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-# File upload handler for plik server
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$fileserver_url/upload"
-    headers = ["Content-Type" => "application/json"]
-    body = """{ "OneShot" : true }"""
-    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
-    responseJson = JSON.parse(String(httpResponse.body))
-    uploadid = responseJson["id"]
-    uploadtoken = responseJson["uploadToken"]
-    
-    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
-    url_upload = "$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
-
-# Send a simple text message
-function send_text_message()
-    message_text = "Hello, how are you today?"
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("message", message_text, "text")],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Sent text message with correlation ID: $(env.correlationId)")
-end
-
-send_text_message()
-```
-
-### Receiver (User 2)
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-# Include the bridge module
-include("NATSBridge.jl")
-using .NATSBridge
-
-# Configuration
-const NATS_URL = "nats://localhost:4222"
-const SUBJECT = "/chat/room1"
-
-# Message handler
-function message_handler(msg::NATS.Msg)
-    payloads = NATSBridge.smartreceive(
-        msg,
-        max_retries = 5,
-        base_delay = 100,
-        max_delay = 5000
-    )
-    
-    # Extract the text message
-    for (dataname, data, data_type) in payloads
-        if data_type == "text"
-            println("Received message: $data")
-            # Save to file
-            write("./received_$dataname.txt", data)
-        end
-    end
-end
-
-# Subscribe to the chat room
-NATS.subscribe(SUBJECT) do msg
-    message_handler(msg)
-end
-
-# Keep the program running
-while true
-    sleep(1)
-end
-```
-
-## Step 4: Adding Image Support
-
-### Sending an Image
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$fileserver_url/upload"
-    headers = ["Content-Type" => "application/json"]
-    body = """{ "OneShot" : true }"""
-    httpResponse = HTTP.request("POST", url_getUploadID, headers, body; body_is_form=false)
-    responseJson = JSON.parse(String(httpResponse.body))
-    uploadid = responseJson["id"]
-    uploadtoken = responseJson["uploadToken"]
-    
-    file_multipart = HTTP.Multipart(dataname, IOBuffer(data), "application/octet-stream")
-    url_upload = "$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
-
-function send_image()
-    # Read image file
-    image_data = read("screenshot.png", Vector{UInt8})
-    
-    # Send with text message
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [
-            ("text", "Check out this screenshot!", "text"),
-            ("screenshot", image_data, "image")
-        ],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Sent image with correlation ID: $(env.correlationId)")
-end
-
-send_image()
-```
-
-### Receiving an Image
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const SUBJECT = "/chat/room1"
-
-function message_handler(msg::NATS.Msg)
-    payloads = NATSBridge.smartreceive(
-        msg,
-        max_retries = 5,
-        base_delay = 100,
-        max_delay = 5000
-    )
-    
-    for (dataname, data, data_type) in payloads
-        if data_type == "text"
-            println("Text: $data")
-        elseif data_type == "image"
-            # Save image to file
-            filename = "received_$dataname.bin"
-            write(filename, data)
-            println("Saved image: $filename")
-        end
-    end
-end
-
-NATS.subscribe(SUBJECT) do msg
-    message_handler(msg)
-end
-```
-
-## Step 5: Handling Large Files with Link Transport
-
-### Automatic Transport Selection
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function send_large_file()
-    # Create a large file (> 1MB triggers link transport)
-    large_data = rand(10_000_000)  # ~80MB
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("large_file", large_data, "binary")],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Uploaded large file to: $(env.payloads[1].data)")
-    println("Correlation ID: $(env.correlationId)")
-end
-
-send_large_file()
-```
-
-## Step 6: Audio and Video Support
-
-### Sending Audio
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function send_audio()
-    # Read audio file (WAV, MP3, etc.)
-    audio_data = read("voice_message.mp3", Vector{UInt8})
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("voice_message", audio_data, "audio")],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Sent audio message: $(env.correlationId)")
-end
-
-send_audio()
-```
-
-### Sending Video
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function send_video()
-    # Read video file (MP4, AVI, etc.)
-    video_data = read("video_message.mp4", Vector{UInt8})
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("video_message", video_data, "video")],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Sent video message: $(env.correlationId)")
-end
-
-send_video()
-```
-
-## Step 7: Table/Data Exchange
-
-### Sending Tabular Data
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function send_table()
-    # Create a DataFrame
-    df = DataFrame(
-        id = 1:5,
-        name = ["Alice", "Bob", "Charlie", "Diana", "Eve"],
-        score = [95, 88, 92, 98, 85],
-        grade = ['A', 'B', 'A', 'B', 'B']
-    )
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("student_scores", df, "table")],
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Sent table with $(nrow(df)) rows")
-end
-
-send_table()
-```
-
-### Receiving and Using Tables
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const SUBJECT = "/chat/room1"
-
-function message_handler(msg::NATS.Msg)
-    payloads = NATSBridge.smartreceive(
-        msg,
-        max_retries = 5,
-        base_delay = 100,
-        max_delay = 5000
-    )
-    
-    for (dataname, data, data_type) in payloads
-        if data_type == "table"
-            data = DataFrame(data)
-            println("Received table:")
-            show(data)
-            println("\nAverage score: $(mean(data.score))")
-        end
-    end
-end
-
-NATS.subscribe(SUBJECT) do msg
-    message_handler(msg)
-end
-```
-
-## Step 8: Bidirectional Communication
-
-### Request-Response Pattern
-
-```julia
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-include("NATSBridge.jl")
-using .NATSBridge
-
-const NATS_URL = "nats://localhost:4222"
-const SUBJECT = "/api/query"
-const REPLY_SUBJECT = "/api/response"
-
-# Request
-function send_request()
-    query_data = Dict("query" => "SELECT * FROM users")
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        [("sql_query", query_data, "dictionary")],
-        nats_url = NATS_URL,
-        fileserver_url = "http://localhost:8080",
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "request",
-        sender_name = "frontend",
-        receiver_name = "backend",
-        reply_to = REPLY_SUBJECT,
-        reply_to_msg_id = string(uuid4())
-    )
-    
-    println("Request sent: $(env.correlationId)")
-end
-
-# Response handler
-function response_handler(msg::NATS.Msg)
-    payloads = NATSBridge.smartreceive(
-        msg,
-        max_retries = 5,
-        base_delay = 100,
-        max_delay = 5000
-    )
-    
-    for (dataname, data, data_type) in payloads
-        if data_type == "table"
-            data = DataFrame(data)
-            println("Query results:")
-            show(data)
-        end
-    end
-end
-
-NATS.subscribe(REPLY_SUBJECT) do msg
-    response_handler(msg)
-end
-```
-
-## Step 9: Complete Chat Application
-
-### Full Chat System
-
-```julia
-module ChatApp
-using NATS
-using JSON
-using UUIDs
-using Dates
-using PrettyPrinting
-using DataFrames
-using Arrow
-using HTTP
-using Base64
-
-# Include the bridge module
-include("../src/NATSBridge.jl")
-using .NATSBridge
-
-# Configuration
-const NATS_URL = "nats://localhost:4222"
-const FILESERVER_URL = "http://localhost:8080"
-const SUBJECT = "/chat/room1"
-
-# File upload handler for plik server
-function plik_upload_handler(fileserver_url::String, dataname::String, data::Vector{UInt8})::Dict{String, Any}
-    url_getUploadID = "$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"]
-    
-    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
-
-function send_chat_message(
-    text::String,
-    image_path::Union{String, Nothing}=nothing,
-    audio_path::Union{String, Nothing}=nothing
-)
-    # Build payloads list
-    payloads = [("message_text", text, "text")]
-    
-    if image_path !== nothing
-        image_data = read(image_path, Vector{UInt8})
-        push!(payloads, ("user_image", image_data, "image"))
-    end
-    
-    if audio_path !== nothing
-        audio_data = read(audio_path, Vector{UInt8})
-        push!(payloads, ("user_audio", audio_data, "audio"))
-    end
-    
-    env = NATSBridge.smartsend(
-        SUBJECT,
-        payloads,
-        nats_url = NATS_URL,
-        fileserver_url = FILESERVER_URL,
-        fileserverUploadHandler = plik_upload_handler,
-        size_threshold = 1_000_000,
-        correlation_id = string(uuid4()),
-        msg_purpose = "chat",
-        sender_name = "user-1"
-    )
-    
-    println("Message sent with correlation ID: $(env.correlationId)")
-end
-
-function receive_chat_messages()
-    function message_handler(msg::NATS.Msg)
-        payloads = NATSBridge.smartreceive(
-            msg,
-            max_retries = 5,
-            base_delay = 100,
-            max_delay = 5000
-        )
-        
-        println("\n--- New Message ---")
-        for (dataname, data, data_type) in payloads
-            if data_type == "text"
-                println("Text: $data")
-            elseif data_type == "image"
-                filename = "received_$dataname.bin"
-                write(filename, data)
-                println("Image saved: $filename")
-            elseif data_type == "audio"
-                filename = "received_$dataname.bin"
-                write(filename, data)
-                println("Audio saved: $filename")
-            elseif data_type == "table"
-                println("Table received:")
-                data = DataFrame(data)
-                show(data)
-            end
-        end
-    end
-    
-    NATS.subscribe(SUBJECT) do msg
-        message_handler(msg)
-    end
-    println("Subscribed to: $SUBJECT")
-end
-
-function run_interactive_chat()
-    println("\n=== Interactive Chat ===")
-    println("1. Send a message")
-    println("2. Join a chat room")
-    println("3. Exit")
-    
-    while true
-        print("\nSelect option (1-3): ")
-        choice = readline()
-        
-        if choice == "1"
-            print("Enter message text: ")
-            text = readline()
-            send_chat_message(text)
-        elseif choice == "2"
-            receive_chat_messages()
-        elseif choice == "3"
-            break
-        end
-    end
-end
-
-end # module
-
-# Run the chat app
-using .ChatApp
-ChatApp.run_interactive_chat()
-```
-
-## Step 10: Testing the Chat System
-
-### Test Scenario 1: Text-Only Chat
-
-```bash
-# Terminal 1: Start the chat receiver
-julia test_julia_to_julia_text_receiver.jl
-
-# Terminal 2: Send a message
-julia test_julia_to_julia_text_sender.jl
-```
-
-### Test Scenario 2: Image Chat
-
-```bash
-# Terminal 1: Receive messages
-julia test_julia_to_julia_mix_payloads_receiver.jl
-
-# Terminal 2: Send image
-julia test_julia_to_julia_mix_payload_sender.jl
-```
-
-### Test Scenario 3: Large File Transfer
-
-```bash
-# Terminal 2: Send large file
-julia test_julia_to_julia_mix_payload_sender.jl
-```
-
-## Conclusion
-
-This walkthrough demonstrated how to build a chat system using NATSBridge.jl with support for:
-
-- Text messages
-- Images (direct transport for small, link transport for large)
-- Audio files
-- Video files
-- Tabular data (DataFrames)
-- Bidirectional communication
-- Mixed-content messages
-
-The key takeaways are:
-
-1. **Always wrap payloads in a list** - Even for single payloads: `[("dataname", data, "type")]`
-2. **Use appropriate transport** - NATSBridge automatically handles size-based routing
-3. **Support mixed content** - Multiple payloads of different types in one message
-4. **Handle errors** - Implement proper error handling for network failures
-5. **Use correlation IDs** - Track messages across distributed systems
-
-For more information, see:
-- [`docs/architecture.md`](./docs/architecture.md) - Detailed architecture documentation
-- [`docs/implementation.md`](./docs/implementation.md) - Implementation details