# 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, broker_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" }
], { broker_url: "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; broker_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
    broker_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}
    {
        broker_url: "nats://localhost:4222",
        fileserver_url: "http://localhost:8080",
        fileserver_upload_handler: customUploadHandler,
        size_threshold: 1_000_000,
        correlation_id: "custom-id",
        msg_purpose: "chat",
        sender_name: "NATSBridge",
        receiver_name: "",
        receiver_id: "",
        reply_to: "",
        reply_to_msg_id: "",
        is_publish: 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)
    broker_url::String = "nats://localhost:4222",
    fileserver_url = "http://localhost:8080",
    fileserver_upload_handler::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
    NATS_connection::Union{NATS.Connection, Nothing} = nothing  # Pre-existing NATS connection (optional, saves connection overhead)
)
# 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 = NATSBridge.smartreceive(
    msg::NATS.Msg;
    fileserver_download_handler::Function = _fetch_with_backoff,
    max_retries::Int = 5,
    base_delay::Int = 100,
    max_delay::Int = 5000
)
# Returns: Dict with envelope metadata and payloads array
```

### publish_message

Publish a message to a NATS subject. This function is available in Julia with two overloads:

#### Julia

**Using broker URL (creates new connection):**
```julia
using NATSBridge, NATS

# Publish with URL - creates a new connection
NATSBridge.publish_message(
    "nats://localhost:4222",  # broker_url
    "/chat/room1",            # subject
    "{\"correlation_id\":\"abc123\"}",  # message
    "abc123"                  # correlation_id
)
```

**Using pre-existing connection (saves connection overhead):**
```julia
using NATSBridge, NATS

# Create connection once and reuse
conn = NATS.connect("nats://localhost:4222")
NATSBridge.publish_message(conn, "/chat/room1", "{\"correlation_id\":\"abc123\"}", "abc123")
# Connection is automatically drained after publish
```

---

## 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" }
], { fileserver_url: "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" }
], {
    fileserver_url: "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")],
    broker_url="nats://localhost:4222",
    reply_to="/device/response"
)
# env: MessageEnvelope 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"
NATS_URL = "nats://localhost:4222"

async def main():
    nc = await nats.connect(NATS_URL)
    
    async def message_handler(msg):
        # Receive and parse the incoming message envelope
        env = smartreceive(msg.data)
        
        # Extract reply_to from the envelope metadata
        reply_to = env["reply_to"]
        
        for dataname, data, type in env["payloads"]:
            if data.get("action") == "read_sensor":
                response = {"sensor_id": "sensor-001", "value": 42.5}
                # Send response to the reply_to subject from the request
                if reply_to:
                    smartsend(reply_to, [("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" }
], {
    broker_url: "nats://localhost:4222",
    reply_to: "/device/response"
});
```

#### JavaScript (Responder)
```javascript
const { smartreceive, smartsend } = require('./src/NATSBridge');
const { connect } = require('nats');

// Configuration
const SUBJECT = "/device/command";
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);
        
        // Extract reply_to from the envelope metadata
        const replyTo = env["reply_to"];
        
        for (const payload of env.payloads) {
            if (payload.dataname === "command" && payload.data.action === "read_sensor") {
                const response = { sensor_id: "sensor-001", value: 42.5 };
                // Send response to the reply_to subject from the request
                if (replyTo) {
                    await smartsend(replyTo, [
                        { 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")];
    broker_url="nats://localhost:4222",
    reply_to="/device/response"
)
```

#### Julia (Responder)
```julia
using NATS, NATSBridge

# Configuration
const SUBJECT = "/device/command"
const NATS_URL = "nats://localhost:4222"

function test_responder()
    conn = NATS.connect(NATS_URL)
    NATS.subscribe(conn, SUBJECT) do msg
        env = NATSBridge.smartreceive(msg, fileserver_download_handler=_fetch_with_backoff)
        
        # Extract reply_to from the envelope metadata
        reply_to = env["reply_to"]
        
        for (dataname, data, type) in env["payloads"]
            if dataname == "command" && data["action"] == "read_sensor"
                response = Dict("sensor_id" => "sensor-001", "value" => 42.5)
                # Send response to the reply_to subject from the request
                if !isempty(reply_to)
                    smartsend(reply_to, [("data", response, "dictionary")])
                end
            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, broker_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.