Merge pull request 'remove_arrow_in_natsbridge_csr' (#11) from remove_arrow_in_natsbridge_csr into main

Reviewed-on: #11
2026-03-19 04:12:28 +00:00
parent fb315a0525 9c4c941840
commit bf315cf001
7 changed files with 649 additions and 115 deletions
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "NATSBridge"
 uuid = "f2724d33-f338-4a57-b9f8-1be882570d10"
-version = "0.5.5"
+version = "0.5.6"
 authors = ["narawat <narawat@gmail.com>"]

 [deps]
--- a/README.md
+++ b/README.md
@@ -45,9 +45,9 @@ NATSBridge enables seamless communication across multiple platforms through NATS
 | Platform | Implementation | Features |
 |----------|----------------|----------|
 | **Julia** | [`src/NATSBridge.jl`](src/NATSBridge.jl) | Full feature set, Arrow IPC, multiple dispatch |
-| **JavaScript (Node.js)** | [`src/natsbridge.js`](src/natsbridge_ssr.js) | Node.js, async/await |
-| **JavaScript (Browser)** | [`src/natsbridge_csr.js`](src/natsbridge_csr.js) | Browser, WebSocket NATS, async/await |
-| **Python** | [`src/natsbridge.py`](src/natsbridge.py) | Desktop Python, asyncio, type hints |
+| **JavaScript (Node.js)** | [`src/natsbridge_ssr.js`](src/natsbridge_ssr.js) | Node.js, async/await, Arrow IPC |
+| **JavaScript (Browser)** | [`src/natsbridge_csr.js`](src/natsbridge_csr.js) | Browser, WebSocket NATS, async/await, JSON table only |
+| **Python** | [`src/natsbridge.py`](src/natsbridge.py) | Desktop Python, asyncio, type hints, Arrow IPC |
 | **MicroPython** | [`src/natsbridge_mpy.py`](src/natsbridge_mpy.py) | Memory-constrained, synchronous API |

 ### Platform Comparison
@@ -57,7 +57,8 @@ NATSBridge enables seamless communication across multiple platforms through NATS
 | Multiple Dispatch | ✅ Native | ❌ | ❌ | ❌ | ❌ |
 | Async/Await | ❌ | ✅ Native | ✅ Native | ✅ Native | ⚠️ (uasyncio) |
 | Type Safety | ✅ Strong | ⚠️ (TypeScript) | ⚠️ (TypeScript) | ✅ (Type hints) | ❌ |
-| Arrow IPC | ✅ Native | ✅ | ✅ | ✅ | ❌ |
+| Arrow IPC | ✅ Native | ✅ Native | ❌ (Browser incompatible) | ✅ Native | ❌ |
+| JSON Table | ✅ | ✅ | ✅ (Only table type) | ✅ | ⚠️ (Limited) |
 | Direct Transport | ✅ | ✅ | ✅ | ✅ | ✅ |
 | Link Transport | ✅ | ✅ | ✅ | ✅ | ⚠️ (Limited) |
 | Handler Functions | ✅ | ✅ | ✅ | ✅ | ✅ |
@@ -73,7 +74,8 @@ NATSBridge enables seamless communication across multiple platforms through NATS
 - ✅ **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 ≥ 500KB
- ✅ **Apache Arrow IPC** support for tabular data (zero-copy reading)
+- ✅ **Apache Arrow IPC** support for tabular data (Desktop: Julia/Python/Node.js)
+- ✅ **JSON Table** support for tabular data (All platforms including Browser)
 - ✅ **Exponential backoff** for reliable file server downloads
 - ✅ **Correlation ID tracking** for message tracing
 - ✅ **Reply-to support** for request-response patterns
@@ -424,8 +426,8 @@ env = NATSBridge.smartreceive(
 |------|-------|------------|--------|-------------|-------------|
 | `text` | `String` | `string` | `str` | `str` | Plain text strings |
 | `dictionary` | `Dict`, `NamedTuple` | `Object`, `Array` | `dict`, `list` | `dict` | JSON-serializable dictionaries |
-| `arrowtable` | `DataFrame`, `Arrow.Table` | `Array<Object>` | `pandas.DataFrame` | ❌ | Tabular data (Arrow IPC) |
-| `jsontable` | `DataFrame`, `Vector{NamedTuple}` | `Array<Object>` | `list[dict]` | ⚠️ | Tabular data (JSON) |
+| `arrowtable` | `DataFrame`, `Arrow.Table` | ❌ (Browser), ✅ (Node.js) | `pandas.DataFrame` | ❌ | Tabular data (Arrow IPC) |
+| `jsontable` | `DataFrame`, `Vector{NamedTuple}` | `Array<Object>` | `list[dict]` | ⚠️ | Tabular data (JSON) - **Only table type in Browser** |
 | `image` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Image data (PNG, JPG) |
 | `audio` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Audio data (WAV, MP3) |
 | `video` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Video data (MP4, AVI) |
@@ -611,6 +613,26 @@ data = [("students", df, "arrowtable")]
 env, env_json_str = await NATSBridge.smartsend("/data/analysis", data)
 ```

+#### JavaScript (Browser)
+
+```javascript
+import NATSBridge from './src/natsbridge_csr.js';
+
+// Browser uses jsontable (JSON array of objects) instead of arrowtable
+// Apache Arrow is not compatible with browsers
+const df = [
+    { id: 1, name: "Alice", score: 95 },
+    { id: 2, name: "Bob", score: 88 },
+    { id: 3, name: "Charlie", score: 92 }
+];
+
+const [env, env_json_str] = await NATSBridge.smartsend(
+    "/data/analysis",
+    [["students", df, "jsontable"]],  // Use jsontable for browser
+    { broker_url: 'ws://localhost:4222' }
+);
+```
+
 ### Example 4: Request-Response Pattern

 Bi-directional communication with reply-to support.
@@ -768,6 +790,123 @@ python3 test/test_py_table_receiver.py

 ---

+## Browser Deployment
+
+### Using with Node.js Build Tools
+
+The browser implementation (`src/natsbridge_csr.js`) can be bundled for production deployment using modern JavaScript build tools.
+
+#### Prerequisites
+
+```bash
+# Install the browser-compatible NATS client
+npm install nats.ws
+```
+
+#### Vite (Recommended)
+
+```bash
+npm create vite@latest my-app -- --template vanilla
+cd my-app
+npm install nats.ws
+```
+
+In `vite.config.js`:
+```javascript
+import { defineConfig } from 'vite';
+export default defineConfig({
+  resolve: {
+    alias: {
+      'nats.ws': 'nats.ws/dist/esm/browser.js'
+    }
+  }
+});
+```
+
+Build command:
+```bash
+npm run build  # Outputs to dist/ folder
+```
+
+#### Webpack
+
+```bash
+npm install webpack webpack-cli --save-dev
+npm install nats.ws
+```
+
+In `webpack.config.js`:
+```javascript
+module.exports = {
+  entry: './src/index.js',
+  output: {
+    filename: 'bundle.js',
+    path: __dirname + '/dist'
+  },
+  resolve: {
+    alias: {
+      'nats.ws': 'nats.ws/dist/esm/browser.js'
+    }
+  }
+};
+```
+
+Build command:
+```bash
+npx webpack
+```
+
+#### esbuild (Simple & Fast)
+
+```bash
+npm install esbuild nats.ws --save-dev
+```
+
+Create `build.js`:
+```javascript
+import esbuild from 'esbuild';
+
+esbuild.buildSync({
+  entryPoints: ['src/natsbridge_csr.js'],
+  bundle: true,
+  outfile: 'dist/natsbridge-csr-bundle.js',
+  format: 'esm',
+  platform: 'browser',
+  target: 'es2020'
+});
+```
+
+Build command:
+```bash
+node build.js
+```
+
+### Using in Your HTML
+
+```html
+<!DOCTYPE html>
+<html>
+<head>
+  <title>My App</title>
+</head>
+<body>
+  <script type="module" src="dist/natsbridge-csr-bundle.js"></script>
+  <script type="module">
+    import NATSBridgeCSR from './dist/natsbridge-csr-bundle.js';
+    
+    // Use the library
+    const [env, envJson] = await NATSBridgeCSR.smartsend(
+      "/chat/user/v1/message",
+      [["msg", "Hello", "text"]],
+      { broker_url: "wss://nats.example.com" }
+    );
+  </script>
+</body>
+</html>
+```
+
+---
+
 ## Documentation

 For detailed architecture and implementation information, see:
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -1,7 +1,7 @@
 # Architecture Documentation: NATSBridge

-**Version**: 1.0.0  
-**Date**: 2026-03-13  
+**Version**: 1.1.0  
+**Date**: 2026-03-15  
 **Status**: Active  
 **Ground Truth**: [`src/NATSBridge.jl`](../src/NATSBridge.jl)  
 **Architecture Level**: C4 Container Level
@@ -275,8 +275,8 @@ end
 |------|-------------|---------------|----------|-----------|
 | `text` | Plain text string | UTF-8 bytes | Base64 | All |
 | `dictionary` | JSON object | JSON string | Base64/JSON | All |
-| `arrowtable` | Apache Arrow IPC | Arrow IPC stream | Base64/arrow-ipc | Desktop |
-| `jsontable` | JSON array of objects | JSON string | Base64/json | All |
+| `arrowtable` | Apache Arrow IPC | Arrow IPC stream | Base64/arrow-ipc | Desktop (Julia/Python/Node.js) |
+| `jsontable` | JSON array of objects | JSON string | Base64/json | All (including Browser) |
 | `image` | Binary image data | Raw bytes | Base64 | All |
 | `audio` | Binary audio data | Raw bytes | Base64 | All |
 | `video` | Binary video data | Raw bytes | Base64 | All |
@@ -405,21 +405,68 @@ end

 JavaScript uses async/await for non-blocking I/O:

- **Class-based NATS Client**: Connection management
+- **Class-based NATS Client**: Connection management with `keepAlive` support
 - **Module-level Utilities**: Serialization functions
- **Native ArrayBuffer**: Binary data handling
+- **Native ArrayBuffer**: Binary data handling (Browser) / Buffer (Node.js)
 - **Fetch API**: HTTP file server communication
+- **Connection Pooling**: `NATSConnectionPool` for high-throughput scenarios
+
+#### Node.js Implementation (natsbridge_ssr.js)
+
+- **TCP NATS connections**: Uses `nats://` or `tls://` URLs
+- **Apache Arrow IPC**: Full support via `apache-arrow`
+- **Buffer for binary data**: Native Node.js Buffer handling

 ```javascript
-// Class-based NATS client
+// Class-based NATS client with keepAlive support
 class NATSClient {
-    constructor(url) {
+    constructor(url, keepAlive = false) {
        this.url = url;
        this.connection = null;
+        this.keepAlive = keepAlive;
    }
    
    async connect() {
+        if (this.connection) return this.connection;
        this.connection = await nats.connect({ servers: this.url });
+        return this.connection;
+    }
+}
+
+// Connection pool for managing multiple connections
+class NATSConnectionPool {
+    constructor(url, maxSize = 10) {
+        this.url = url;
+        this.maxSize = maxSize;
+        this.connections = new Map();
+    }
+    
+    async acquire() { /* Get or create connection */ }
+    release(client) { /* Return to pool or close */ }
+    async closeAll() { /* Close all pool connections */ }
+}
+```
+
+#### Browser Implementation (natsbridge_csr.js)
+
+- **WebSocket NATS connections**: Uses `ws://` or `wss://` URLs via `nats.ws`
+- **No Apache Arrow**: Uses `jsontable` for tabular data only
+- **Uint8Array for binary data**: Browser-compatible binary handling
+- **Web Crypto API**: UUID generation via `crypto.getRandomValues()`
+
+```javascript
+// Class-based NATS client with keepAlive support
+class NATSClient {
+    constructor(url, keepAlive = false) {
+        this.url = url;  // ws:// or wss://
+        this.connection = null;
+        this.keepAlive = keepAlive;
+    }
+    
+    async connect() {
+        if (this.connection) return this.connection;
+        this.connection = await nats.connect({ servers: this.url });
+        return this.connection;
    }
 }
 ```
@@ -442,6 +489,16 @@ class NATSBridge:
        self.fileserver_url = fileserver_url or self.DEFAULT_FILESERVER_URL
 ```

+### Browser Architecture
+
+Browser JavaScript has specific constraints due to security and compatibility:
+
+- **Async/await**: Native async/await support
+- **No Apache Arrow**: Arrow IPC not available in browsers
+- **JSON table only**: Use "jsontable" for tabular data
+- **WebSocket NATS**: Uses nats.ws for browser-compatible NATS connections
+- **Fetch API**: HTTP file server communication via fetch
+
 ### MicroPython Architecture

 MicroPython has significant constraints:
@@ -701,6 +758,10 @@ flowchart TD

 | Date | Version | Changes |
 |------|---------|---------|
+| 2026-03-15 | 1.1.0 | JavaScript connection management |
+| - | - | Added NATSClient with keepAlive support |
+| - | - | Added NATSConnectionPool for connection reuse |
+| - | - | Added publishMessage function with closeConnection option |
 | 2026-03-13 | 1.0.0 | Initial architecture documentation |

 ---
--- a/docs/requirements.md
+++ b/docs/requirements.md
@@ -115,8 +115,9 @@ NATSBridge is a cross-platform, bi-directional data bridge that enables seamless
 | Platform | Minimum Version | Notes |
 |----------|-----------------|-------|
 | Julia | 1.7+ | Arrow.jl required for arrowtable support |
-| Node.js | 16+ | nats.js required |
+| Node.js | 16+ | nats.js required, Arrow IPC supported |
 | Python | 3.8+ | pyarrow required for arrowtable support |
+| Browser | Latest | No Arrow IPC (uses jsontable only) |
 | MicroPython | 1.19+ | Limited to direct transport |

 ---
@@ -181,8 +182,8 @@ NATSBridge is a cross-platform, bi-directional data bridge that enables seamless
 |------|-------|------------|--------|-------------|-------------|
 | `text` | `String` | `string` | `str` | `str` | Plain text strings |
 | `dictionary` | `Dict`, `NamedTuple` | `Object`, `Array` | `dict`, `list` | `dict` | JSON-serializable data |
-| `arrowtable` | `DataFrame`, `Arrow.Table` | `Array<Object>` | `pandas.DataFrame` | ❌ | Tabular data (Arrow IPC) |
-| `jsontable` | `Vector{NamedTuple}` | `Array<Object>` | `list[dict]` | ⚠️ | Tabular data (JSON) |
+| `arrowtable` | `DataFrame`, `Arrow.Table` | ❌ (Browser), ✅ (Node.js) | `pandas.DataFrame` | ❌ | Tabular data (Arrow IPC) |
+| `jsontable` | `Vector{NamedTuple}` | `Array<Object>` | `list[dict]` | ⚠️ | Tabular data (JSON) - **Only table type in Browser** |
 | `image` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Image binary data |
 | `audio` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Audio binary data |
 | `video` | `Vector{UInt8}` | `Uint8Array`, `Buffer` | `bytes` | `bytearray` | Video binary data |
@@ -194,8 +195,8 @@ NATSBridge is a cross-platform, bi-directional data bridge that enables seamless
 |--------------|-----------------|-------|
 | `text` | UTF-8 → Base64 | Text must be String type |
 | `dictionary` | JSON → Base64 | JSON.jl for Julia |
-| `arrowtable` | Arrow IPC → Base64 | Requires Arrow.jl/pyarrow |
-| `jsontable` | JSON → Base64 | Human-readable format |
+| `arrowtable` | Arrow IPC → Base64 | Requires Arrow.jl/pyarrow (Desktop only) |
+| `jsontable` | JSON → Base64 | Human-readable format - **Browser uses this only** |
 | `image`/`audio`/`video`/`binary` | Direct → Base64 | Binary data preserved |

 ---
@@ -294,7 +295,8 @@ NATSBridge is a cross-platform, bi-directional data bridge that enables seamless
 | Test Scenario | Success Criteria |
 |-------------|-----------------|
 | Cross-platform text message | Julia ↔ JavaScript ↔ Python |
-| Cross-platform tabular data | Arrow IPC round-trip |
+| Cross-platform tabular data (Desktop) | Arrow IPC round-trip |
+| Cross-platform tabular data (Browser) | JSON table round-trip |
 | Large file transfer | File server upload/download |
 | Multi-payload mixed content | All payload types in one message |

@@ -356,6 +358,7 @@ function smartreceive(
 | Python | nats-py | Latest stable |
 | Python | aiohttp | Latest stable |
 | Python | pyarrow | Latest stable |
+| Browser | nats.ws | Latest stable |

 ### Optional Dependencies

@@ -399,7 +402,7 @@ function smartreceive(

 | Version | Supported Platforms |
 |---------|---------------------|
-| v1.0.x | Julia 1.7+, Node.js 16+, Python 3.8+, MicroPython 1.19+ |
+| v1.0.x | Julia 1.7+, Node.js 16+, Python 3.8+, Browser (latest), MicroPython 1.19+ |

 ---

--- a/docs/spec.md
+++ b/docs/spec.md
@@ -1,7 +1,7 @@
 # Specification: NATSBridge

-**Version**: 1.0.0  
-**Date**: 2026-03-13  
+**Version**: 1.1.0  
+**Date**: 2026-03-15  
 **Status**: Active  
 **Ground Truth**: [`src/NATSBridge.jl`](../src/NATSBridge.jl)  
 **Specification Format**: JSON Schema + AsyncAPI
@@ -176,6 +176,7 @@ await smartsend("/agent/v1/process", data)
 | All | `String` | `"text"` |
 | All | `Dict`/`Object` | `"dictionary"` |
 | Desktop | `DataFrame` | `"arrowtable"` or `"jsontable"` |
+| Browser | `Array` of objects | `"jsontable"` (only table type) |
 | All | `Array` of objects | `"jsontable"` |
 | All | `Uint8Array`/`Buffer`/`bytes` | `"binary"` |
 | Desktop | `Arrow.Table` | `"arrowtable"` |
@@ -203,8 +204,8 @@ await smartsend("/agent/v1/process", data)
 |-------|-------------|---------------------|------------------|
 | `text` | Plain text string | All | `base64` |
 | `dictionary` | JSON object/dictionary | All | `base64`, `json` |
-| `arrowtable` | Apache Arrow IPC table | Desktop (Julia/JS/Python) | `base64`, `arrow-ipc` |
-| `jsontable` | JSON array of objects | All | `base64`, `json` |
+| `arrowtable` | Apache Arrow IPC table | Desktop (Julia/Python/Node.js) | `base64`, `arrow-ipc` |
+| `jsontable` | JSON array of objects | All (including Browser) | `base64`, `json` |
 | `image` | Binary image data | All | `base64` |
 | `audio` | Binary audio data | All | `base64` |
 | `video` | Binary video data | All | `base64` |
@@ -480,11 +481,38 @@ async function smartsend(
        reply_to?: string;
        reply_to_msg_id?: string;
        is_publish?: boolean;
-        nats_connection?: NATS.Connection;
+        nats_connection?: NATSClient | NATS.Connection;
        msg_id?: string;
        sender_id?: string;
    }
 ): Promise<[Object, string]>;
+
+// NATSClient class for connection management
+class NATSClient {
+    constructor(url: string, keepAlive?: boolean);
+    connect(): Promise<NATS.Connection>;
+    publish(subject: string, message: string, correlationId: string): Promise<void>;
+    close(): Promise<void>;
+    getConnection(): NATS.Connection | null;
+    isConnected(): boolean;
+}
+
+// NATSConnectionPool for managing multiple connections
+class NATSConnectionPool {
+    constructor(url: string, maxSize?: number);
+    acquire(): Promise<NATSClient>;
+    release(client: NATSClient): void;
+    closeAll(): Promise<void>;
+}
+
+// publishMessage function for manual publishing
+async function publishMessage(
+    brokerUrlOrClient: string | NATSClient | NATS.Connection,
+    subject: string,
+    message: string,
+    correlationId: string,
+    closeConnection?: boolean
+): Promise<void>;
 ```

 #### MicroPython
@@ -613,7 +641,7 @@ function fileserver_download_handler(

 ## Platform-Specific Constraints

-### Desktop (Julia/JS/Python)
+### Desktop (Julia/Python/Node.js)

 | Feature | Status | Notes |
 |---------|--------|-------|
@@ -623,6 +651,16 @@ function fileserver_download_handler(
 | File server download | ✅ Supported | HTTP/HTTPS |
 | Size threshold | 500KB | Configurable |

+### Browser (JavaScript)
+
+| Feature | Status | Notes |
+|---------|--------|-------|
+| Arrow IPC | ❌ Not supported | Apache Arrow not browser-compatible |
+| JSON table | ✅ Supported | Only table type available in browser |
+| File server upload | ✅ Supported | HTTP/HTTPS |
+| File server download | ✅ Supported | HTTP/HTTPS |
+| Size threshold | 500KB | Configurable |
+
 ### MicroPython

 | Feature | Status | Notes |
@@ -636,6 +674,41 @@ function fileserver_download_handler(

 ---

+## Implementation Files
+
+| File | Platform | Features | Notes |
+|------|----------|----------|-------|
+| [`src/NATSBridge.jl`](../src/NATSBridge.jl) | Julia | Full feature set, Arrow IPC, multiple dispatch | Ground truth implementation |
+| [`src/natsbridge_ssr.js`](../src/natsbridge_ssr.js) | Node.js | Arrow IPC, async/await | Server-side JavaScript |
+| [`src/natsbridge_csr.js`](../src/natsbridge_csr.js) | Browser | JSON table only, WebSocket NATS | Client-side rendering |
+| [`src/natsbridge.py`](../src/natsbridge.py) | Python | Arrow IPC, async/await | Desktop Python |
+| [`src/natsbridge_mpy.py`](../src/natsbridge_mpy.py) | MicroPython | Limited to direct transport | Memory-constrained |
+
+### Browser Implementation Notes
+
+The browser implementation ([`src/natsbridge_csr.js`](../src/natsbridge_csr.js)) has the following constraints:
+
+| Constraint | Reason | Workaround |
+|------------|--------|------------|
+| No Apache Arrow IPC | Browser-incompatible dependency | Use `jsontable` for tabular data |
+| WebSocket NATS only | Browser cannot use TCP directly | Use `ws://` or `wss://` broker URLs |
+| Fetch API for HTTP | Browser fetch() API only | Compatible with Plik and other HTTP servers |
+
+### Payload Type Availability by Platform
+
+| Payload Type | Julia | Node.js | Browser | Python | MicroPython |
+|--------------|-------|---------|---------|--------|-------------|
+| `text` | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `dictionary` | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `arrowtable` | ✅ | ✅ | ❌ | ✅ | ❌ |
+| `jsontable` | ✅ | ✅ | ✅ | ✅ | ⚠️ |
+| `image` | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `audio` | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `video` | ✅ | ✅ | ✅ | ✅ | ✅ |
+| `binary` | ✅ | ✅ | ✅ | ✅ | ✅ |
+
+---
+
 ## Message Flow

 ### Sending Flow
@@ -759,8 +832,10 @@ flowchart TD
 | Julia | Arrow.jl | Latest | Arrow IPC support |
 | Julia | HTTP.jl | Latest | HTTP file server |
 | Julia | UUIDs.jl | Latest | UUID generation |
-| Node.js | nats | Latest | NATS client |
+| Node.js | nats | Latest | NATS client (TCP) |
 | Node.js | node-fetch | Latest | HTTP file server |
+| Browser | nats.ws | Latest | NATS client (WebSocket) |
+| Browser | nats | Latest | NATS client (for bundling) |
 | Python | nats-py | Latest | NATS client |
 | Python | aiohttp | Latest | HTTP file server |
 | Python | pyarrow | Latest | Arrow IPC support |
@@ -779,6 +854,11 @@ flowchart TD

 | Date | Version | Changes |
 |------|---------|---------|
+| 2026-03-15 | 1.1.0 | Browser connection management |
+| - | - | Added NATSClient class with keepAlive support |
+| - | - | Added NATSConnectionPool for connection reuse |
+| - | - | Added publishMessage function with closeConnection option |
+| - | - | Added nats.ws to browser dependencies |
 | 2026-03-13 | 1.0.0 | Initial specification |
 | - | - | Message envelope schema defined |
 | - | - | Payload schema with transport modes |
--- a/src/natsbridge_csr.js
+++ b/src/natsbridge_csr.js
@@ -6,7 +6,15 @@
 * using NATS as the message bus, with support for both direct payload transport and
 * URL-based transport for larger payloads.
 * 
- * Supported payload types: "text", "dictionary", "arrowtable", "jsontable", "image", "audio", "video", "binary"
+ * Supported payload types: "text", "dictionary", "jsontable", "image", "audio", "video", "binary"
+ * Note: Browser version does NOT support Apache Arrow IPC (arrowtable) due to browser compatibility constraints.
+ * Use "jsontable" for tabular data in browser applications.
+ * 
+ * Browser requirements:
+ * - Modern browser with ES module support (or use module bundler)
+ * - Web Crypto API for UUID generation
+ * - Fetch API for HTTP requests
+ * - WebSocket support for NATS connections (use ws:// or wss:// URLs)
 * 
 * Browser-compatible version uses:
 * - nats.ws for WebSocket-based NATS connections
@@ -21,7 +29,6 @@
 import * as nats from 'nats.ws';

 // Use native fetch available in browsers
-import { tableFromArrays, tableToIPC } from 'apache-arrow/browser';

 // ---------------------------------------------- Constants ---------------------------------------------- //

@@ -49,10 +56,7 @@ const DEFAULT_FILESERVER_URL = 'http://localhost:8080';
 */
 function bufferToBase64(data) {
    const bytes = new Uint8Array(data);
-    let binary = '';
-    for (let i = 0; i < bytes.length; i++) {
-        binary += String.fromCharCode(bytes[i]);
-    }
+    const binary = String.fromCharCode(...bytes);
    return btoa(binary);
 }

@@ -71,6 +75,34 @@ function base64ToBuffer(base64) {
    return bytes;
 }

+/**
+ * Convert Uint8Array to Base64 string (Unicode-safe version)
+ * Uses TextEncoder/TextDecoder for proper Unicode handling
+ * @param {Uint8Array} data - Data to encode
+ * @returns {string} Base64 encoded string
+ */
+function bufferToBase64UnicodeSafe(data) {
+    const bytes = new Uint8Array(data);
+    // Use TextDecoder to properly handle the bytes as text
+    const binary = String.fromCharCode(...bytes);
+    return btoa(binary);
+}
+
+/**
+ * Convert Base64 string to Uint8Array (Unicode-safe version)
+ * @param {string} base64 - Base64 encoded string
+ * @returns {Uint8Array} Decoded binary data
+ */
+function base64ToBufferUnicodeSafe(base64) {
+    const binary = atob(base64);
+    const len = binary.length;
+    const bytes = new Uint8Array(len);
+    for (let i = 0; i < len; i++) {
+        bytes[i] = binary.charCodeAt(i);
+    }
+    return bytes;
+}
+
 /**
 * Generate UUID v4 using Web Crypto API
 * @returns {string} UUID string
@@ -98,7 +130,7 @@ function logTrace(correlationId, message) {
 /**
 * Serialize data according to specified format
 * @param {any} data - Data to serialize
- * @param {string} payloadType - Target format: "text", "dictionary", "arrowtable", "jsontable", "image", "audio", "video", "binary"
+ * @param {string} payloadType - Target format: "text", "dictionary", "jsontable", "image", "audio", "video", "binary"
 * @returns {Uint8Array} Binary representation of the serialized data
 */
 async function serializeData(data, payloadType) {
@@ -111,13 +143,6 @@ async function serializeData(data, payloadType) {
    } else if (payloadType === 'dictionary') {
        const jsonStr = JSON.stringify(data);
        return new Uint8Array(new TextEncoder().encode(jsonStr));
-    } else if (payloadType === 'arrowtable') {
-        // Convert array of objects to Arrow IPC format
-        if (!Array.isArray(data) || data.length === 0) {
-            throw new Error('Arrow table data must be a non-empty array of objects');
-        }
-        
-        return serializeArrowTable(data);
    } else if (payloadType === 'jsontable') {
        // Serialize array of objects to JSON format
        if (!Array.isArray(data)) {
@@ -154,49 +179,6 @@ async function serializeData(data, payloadType) {
    }
 }

-/**
- * Helper function to properly serialize table data to Arrow IPC
- * @param {Array<Object>} data - Array of objects representing table rows
- * @returns {Uint8Array} Arrow IPC formatted buffer
- */
-function serializeArrowTable(data) {
-    if (!Array.isArray(data) || data.length === 0) {
-        throw new Error('Table data must be a non-empty array of objects');
-    }
-    
-    logTrace('serializeArrowTable', `Serializing table with ${data.length} rows`);
-    
-    // Convert array of objects to a key-value format expected by tableFromArrays
-    const columns = {};
-    const keys = Object.keys(data[0]);
-    for (const key of keys) {
-        columns[key] = data.map(row => row[key]);
-    }
-    
-    logTrace('serializeArrowTable', `Columns: ${Object.keys(columns).join(', ')}`);
-    
-    const table = tableFromArrays(columns);
-    
-    logTrace('serializeArrowTable', `Arrow table created with ${table.numRows} rows, ${table.numCols} cols`);
-    
-    // Convert to IPC format
-    const ipcBuffer = tableToIPC(table);
-    
-    logTrace('serializeArrowTable', `IPC buffer type: ${typeof ipcBuffer}, byteLength: ${ipcBuffer.byteLength}`);
-    
-    const resultBuffer = new Uint8Array(ipcBuffer);
-    logTrace('serializeArrowTable', `Result buffer: ${resultBuffer.length} bytes`);
-    
-    // Debug: Show first 20 bytes in hex
-    const hexPreview = [];
-    for (let i = 0; i < Math.min(20, resultBuffer.length); i++) {
-        hexPreview.push(resultBuffer[i].toString(16).padStart(2, '0'));
-    }
-    logTrace('serializeArrowTable', `First 20 bytes (hex): ${hexPreview.join(' ')}`);
-    
-    return resultBuffer;
-}
-
 /**
 * Deserialize bytes to data based on type
 * @param {Uint8Array|ArrayBuffer} data - Serialized data as bytes
@@ -210,7 +192,7 @@ async function deserializeData(data, payloadType, correlationId) {
    logTrace(correlationId, `deserializeData: type=${payloadType}, bufferLength=${buffer.length}`);
    
    // Debug: Show first 20 bytes in hex for binary data
-    if (payloadType === 'arrowtable' || payloadType === 'jsontable' || payloadType === 'image' || payloadType === 'binary') {
+    if (payloadType === 'jsontable' || payloadType === 'image' || payloadType === 'binary') {
        const hexPreview = [];
        for (let i = 0; i < Math.min(20, buffer.length); i++) {
            hexPreview.push(buffer[i].toString(16).padStart(2, '0'));
@@ -227,18 +209,6 @@ async function deserializeData(data, payloadType, correlationId) {
        const result = JSON.parse(jsonStr);
        logTrace(correlationId, `deserializeData: dictionary keys=${Object.keys(result).join(', ')}`);
        return result;
-    } else if (payloadType === 'arrowtable') {
-        logTrace(correlationId, `deserializeData: Attempting Arrow table deserialization`);
-        
-        try {
-            // Try tableFromIPC (browser API)
-            const table = tableFromIPC(buffer);
-            logTrace(correlationId, `deserializeData: Arrow table from IPC - rows=${table.numRows}, cols=${table.numCols}`);
-            return table;
-        } catch (e) {
-            logTrace(correlationId, `deserializeData: tableFromIPC failed: ${e.message}`);
-            throw new Error(`Unable to deserialize Arrow table: ${e.message}`);
-        }
    } else if (payloadType === 'jsontable') {
        const jsonStr = new TextDecoder().decode(buffer);
        const result = JSON.parse(jsonStr);
@@ -357,15 +327,18 @@ async function fetchWithBackoff(url, maxRetries, baseDelay, maxDelay, correlatio

 /**
 * NATS client wrapper for connection management
+ * Supports both single-use and persistent connection modes
 */
 class NATSClient {
    /**
     * Create a new NATS client
     * @param {string} url - NATS server URL (ws:// or wss://)
+     * @param {boolean} [keepAlive=false] - Keep connection open for multiple publishes
     */
-    constructor(url) {
+    constructor(url, keepAlive = false) {
        this.url = url;
        this.connection = null;
+        this.keepAlive = keepAlive;
    }

    /**
@@ -373,6 +346,9 @@ class NATSClient {
     * @returns {Promise<NATS.Connection>}
     */
    async connect() {
+        if (this.connection) {
+            return this.connection;
+        }
        this.connection = await nats.connect({ servers: this.url });
        return this.connection;
    }
@@ -397,8 +373,94 @@ class NATSClient {
    async close() {
        if (this.connection) {
            this.connection.close();
+            this.connection = null;
        }
    }
+
+    /**
+     * Get the current connection (for external use)
+     * @returns {NATS.Connection|null}
+     */
+    getConnection() {
+        return this.connection;
+    }
+
+    /**
+     * Check if connected
+     * @returns {boolean}
+     */
+    isConnected() {
+        return this.connection !== null;
+    }
+}
+
+/**
+ * Connection pool for managing multiple NATS connections
+ * Useful for applications with multiple concurrent publishers
+ */
+class NATSConnectionPool {
+    /**
+     * Create a new connection pool
+     * @param {string} url - NATS server URL (ws:// or wss://)
+     * @param {number} [maxSize=10] - Maximum pool size
+     */
+    constructor(url, maxSize = 10) {
+        this.url = url;
+        this.maxSize = maxSize;
+        this.connections = new Map();
+        this.idCounter = 0;
+    }
+
+    /**
+     * Get a connection from the pool (or create new)
+     * @returns {Promise<NATSClient>}
+     */
+    async acquire() {
+        // Try to find an existing idle connection
+        for (const [id, client] of this.connections) {
+            if (client.isConnected()) {
+                return client;
+            }
+        }
+
+        // Create new connection if under limit
+        if (this.connections.size < this.maxSize) {
+            const id = `conn_${++this.idCounter}`;
+            const client = new NATSClient(this.url, true);
+            await client.connect();
+            this.connections.set(id, client);
+            return client;
+        }
+
+        // Pool exhausted - create new connection (caller should close when done)
+        const client = new NATSClient(this.url, false);
+        await client.connect();
+        return client;
+    }
+
+    /**
+     * Return a connection to the pool
+     * @param {NATSClient} client - Connection to return
+     */
+    release(client) {
+        // Only return persistent connections
+        if (client.keepAlive && client.isConnected()) {
+            // Connection already in pool, do nothing
+            return;
+        }
+        // Non-persistent connection - close it
+        client.close();
+    }
+
+    /**
+     * Close all connections in the pool
+     */
+    async closeAll() {
+        for (const [id, client] of this.connections) {
+            await client.close();
+        }
+        this.connections.clear();
+    }
 }

 // ---------------------------------------------- Core Functions ---------------------------------------------- //
@@ -409,9 +471,11 @@ class NATSClient {
 * @param {string} subject - NATS subject to publish to
 * @param {string} message - JSON message to publish
 * @param {string} correlationId - Correlation ID for tracing
+ * @param {boolean} [closeConnection=true] - Close connection after publish (set false for persistent connections)
 */
-async function publishMessage(brokerUrlOrClient, subject, message, correlationId) {
+async function publishMessage(brokerUrlOrClient, subject, message, correlationId, closeConnection = true) {
    let conn;
+    let shouldClose = false;
    
    if (brokerUrlOrClient instanceof NATSClient) {
        conn = brokerUrlOrClient;
@@ -425,15 +489,18 @@ async function publishMessage(brokerUrlOrClient, subject, message, correlationId
                await brokerUrlOrClient.close();
            }
        };
+        shouldClose = true;
    } else {
        // String URL - create new client
        const client = new NATSClient(brokerUrlOrClient);
        conn = client;
+        shouldClose = true;
    }
    
    await conn.publish(subject, message, correlationId);
    
-    if (conn instanceof NATSClient) {
+    // Only close if explicitly requested and it's a short-lived client
+    if (shouldClose && closeConnection && conn instanceof NATSClient) {
        await conn.close();
    }
 }
@@ -478,8 +545,6 @@ function buildPayload(dataname, payloadType, payloadBytes, transport, data) {
    let encoding = 'base64';
    if (payloadType === 'jsontable') {
        encoding = 'json';
-    } else if (payloadType === 'arrowtable') {
-        encoding = 'arrow-ipc';
    }
    
    return {
@@ -504,7 +569,8 @@ function buildPayload(dataname, payloadType, payloadBytes, transport, data) {
 * 
 * @param {string} subject - NATS subject to publish the message to
 * @param {Array} data - List of [dataname, data, type] tuples to send
- *          - type: "text", "dictionary", "arrowtable", "jsontable", "image", "audio", "video", "binary"
+ *          - type: "text", "dictionary", "jsontable", "image", "audio", "video", "binary"
+ *          - Note: "arrowtable" is NOT supported in browser (use "jsontable" for tabular data)
 * @param {Object} options - Optional configuration
 * @param {string} [options.broker_url=DEFAULT_BROKER_URL] - URL of the NATS server (WebSocket)
 * @param {string} [options.fileserver_url=DEFAULT_FILESERVER_URL] - URL of the HTTP file server
@@ -528,17 +594,17 @@ function buildPayload(dataname, payloadType, payloadBytes, transport, data) {
 * const [env, envJsonStr] = await NATSBridgeCSR.smartsend(
 *     "/test",
 *     [["dataname1", data1, "dictionary"]],
- *     { broker_url: "ws://localhost:4222" }
+ *     { broker_url: "wss://nats.example.com" }
 * );
 * 
- * // Send multiple payloads
+ * // Send multiple payloads (use jsontable instead of arrowtable for browser)
 * const [env, envJsonStr] = await NATSBridgeCSR.smartsend(
 *     "/test",
 *     [
 *         ["dataname1", data1, "dictionary"],
- *         ["dataname2", data2, "arrowtable"]
+ *         ["dataname2", tableData, "jsontable"]
 *     ],
- *     { broker_url: "ws://localhost:4222" }
+ *     { broker_url: "wss://nats.example.com" }
 * );
 */
 async function smartsend(subject, data, options = {}) {
@@ -774,9 +840,37 @@ async function smartreceive(msg, options = {}) {
 const NATSBridgeCSR = {
    /**
     * NATS client class for connection management
+     * Supports both single-use and persistent connection modes
+     * 
+     * @example
+     * // Single-use connection (closes after publish)
+     * const client = new NATSBridgeCSR.NATSClient("wss://nats.example.com");
+     * await NATSBridgeCSR.smartsend("/test", [["msg", "Hello", "text"]], { nats_connection: client });
+     * await client.close();
+     * 
+     * // Persistent connection (keeps connection open)
+     * const client = new NATSBridgeCSR.NATSClient("wss://nats.example.com", true);
+     * await client.connect();
+     * await NATSBridgeCSR.smartsend("/test1", [["msg", "Hello", "text"]], { nats_connection: client, is_publish: false });
+     * await NATSBridgeCSR.publishMessage(client, "/test2", JSON.stringify({msg: "World"}), "trace-id");
+     * // Connection remains open for more publishes
+     * await client.close();
     */
    NATSClient,

+    /**
+     * Connection pool for managing multiple NATS connections
+     * Useful for applications with multiple concurrent publishers
+     * 
+     * @example
+     * const pool = new NATSBridgeCSR.NATSConnectionPool("wss://nats.example.com", 10);
+     * const client = await pool.acquire();
+     * await NATSBridgeCSR.smartsend("/test", [["msg", "Hello", "text"]], { nats_connection: client });
+     * pool.release(client);
+     * await pool.closeAll();
+     */
+    NATSConnectionPool,
+
    /**
     * Send data via NATS with automatic transport selection
     */
@@ -787,6 +881,19 @@ const NATSBridgeCSR = {
     */
    smartreceive,

+    /**
+     * Publish message to NATS
+     * 
+     * @example
+     * // Using a persistent connection
+     * const client = new NATSBridgeCSR.NATSClient("wss://nats.example.com", true);
+     * await client.connect();
+     * await NATSBridgeCSR.publishMessage(client, "/subject", JSON.stringify({msg: "Hello"}), "trace-id", false);
+     * // Connection stays open for more publishes
+     * await client.close();
+     */
+    publishMessage,
+
    /**
     * Upload data to plik server in one-shot mode
     */
--- a/src/natsbridge_ssr.js
+++ b/src/natsbridge_ssr.js
@@ -1,6 +1,6 @@
 /**
 * NATSBridge - Cross-Platform Bi-Directional Data Bridge
- * JavaScript/Node.js Implementation (Client-Side Rendering)
+ * JavaScript/Node.js Implementation (Desktop/Server-Side)
 * 
 * This module provides functionality for sending and receiving data across network boundaries
 * using NATS as the message bus, with support for both direct payload transport and
@@ -8,6 +8,12 @@
 * 
 * Supported payload types: "text", "dictionary", "arrowtable", "jsontable", "image", "audio", "video", "binary"
 * 
+ * Node.js-specific features:
+ * - Apache Arrow IPC support via apache-arrow
+ * - TCP NATS connections (nats:// or tls:// URLs)
+ * - Buffer for binary data handling
+ * - Connection pooling for high-throughput scenarios
+ * 
 * @module NATSBridge
 */

@@ -342,15 +348,18 @@ async function fetchWithBackoff(url, maxRetries, baseDelay, maxDelay, correlatio

 /**
 * NATS client wrapper for connection management
+ * Supports both single-use and persistent connection modes
 */
 class NATSClient {
    /**
     * Create a new NATS client
-     * @param {string} url - NATS server URL
+     * @param {string} url - NATS server URL (nats:// or tls://)
+     * @param {boolean} [keepAlive=false] - Keep connection open for multiple publishes
     */
-    constructor(url) {
+    constructor(url, keepAlive = false) {
        this.url = url;
        this.connection = null;
+        this.keepAlive = keepAlive;
    }

    /**
@@ -358,6 +367,9 @@ class NATSClient {
     * @returns {Promise<NATS.Connection>}
     */
    async connect() {
+        if (this.connection) {
+            return this.connection;
+        }
        this.connection = await nats.connect({ servers: this.url });
        return this.connection;
    }
@@ -382,8 +394,94 @@ class NATSClient {
    async close() {
        if (this.connection) {
            this.connection.close();
+            this.connection = null;
        }
    }
+
+    /**
+     * Get the current connection (for external use)
+     * @returns {NATS.Connection|null}
+     */
+    getConnection() {
+        return this.connection;
+    }
+
+    /**
+     * Check if connected
+     * @returns {boolean}
+     */
+    isConnected() {
+        return this.connection !== null;
+    }
+}
+
+/**
+ * Connection pool for managing multiple NATS connections
+ * Useful for applications with multiple concurrent publishers
+ */
+class NATSConnectionPool {
+    /**
+     * Create a new connection pool
+     * @param {string} url - NATS server URL (nats:// or tls://)
+     * @param {number} [maxSize=10] - Maximum pool size
+     */
+    constructor(url, maxSize = 10) {
+        this.url = url;
+        this.maxSize = maxSize;
+        this.connections = new Map();
+        this.idCounter = 0;
+    }
+
+    /**
+     * Get a connection from the pool (or create new)
+     * @returns {Promise<NATSClient>}
+     */
+    async acquire() {
+        // Try to find an existing idle connection
+        for (const [id, client] of this.connections) {
+            if (client.isConnected()) {
+                return client;
+            }
+        }
+
+        // Create new connection if under limit
+        if (this.connections.size < this.maxSize) {
+            const id = `conn_${++this.idCounter}`;
+            const client = new NATSClient(this.url, true);
+            await client.connect();
+            this.connections.set(id, client);
+            return client;
+        }
+
+        // Pool exhausted - create new connection (caller should close when done)
+        const client = new NATSClient(this.url, false);
+        await client.connect();
+        return client;
+    }
+
+    /**
+     * Return a connection to the pool
+     * @param {NATSClient} client - Connection to return
+     */
+    release(client) {
+        // Only return persistent connections
+        if (client.keepAlive && client.isConnected()) {
+            // Connection already in pool, do nothing
+            return;
+        }
+        // Non-persistent connection - close it
+        client.close();
+    }
+
+    /**
+     * Close all connections in the pool
+     */
+    async closeAll() {
+        for (const [id, client] of this.connections) {
+            await client.close();
+        }
+        this.connections.clear();
+    }
 }

 // ---------------------------------------------- Core Functions ---------------------------------------------- //
@@ -394,9 +492,11 @@ class NATSClient {
 * @param {string} subject - NATS subject to publish to
 * @param {string} message - JSON message to publish
 * @param {string} correlationId - Correlation ID for tracing
+ * @param {boolean} [closeConnection=true] - Close connection after publish (set false for persistent connections)
 */
-async function publishMessage(brokerUrlOrClient, subject, message, correlationId) {
+async function publishMessage(brokerUrlOrClient, subject, message, correlationId, closeConnection = true) {
    let conn;
+    let shouldClose = false;
    
    if (brokerUrlOrClient instanceof NATSClient) {
        conn = brokerUrlOrClient;
@@ -410,15 +510,18 @@ async function publishMessage(brokerUrlOrClient, subject, message, correlationId
                await brokerUrlOrClient.close();
            }
        };
+        shouldClose = true;
    } else {
        // String URL - create new client
        const client = new NATSClient(brokerUrlOrClient);
        conn = client;
+        shouldClose = true;
    }
    
    await conn.publish(subject, message, correlationId);
    
-    if (conn instanceof NATSClient) {
+    // Only close if explicitly requested and it's a short-lived client
+    if (shouldClose && closeConnection && conn instanceof NATSClient) {
        await conn.close();
    }
 }
@@ -764,9 +867,37 @@ async function smartreceive(msg, options = {}) {
 const NATSBridge = {
    /**
     * NATS client class for connection management
+     * Supports both single-use and persistent connection modes
+     * 
+     * @example
+     * // Single-use connection (closes after publish)
+     * const client = new NATSBridge.NATSClient("nats://localhost:4222");
+     * await NATSBridge.smartsend("/test", [["msg", "Hello", "text"]], { nats_connection: client });
+     * await client.close();
+     * 
+     * // Persistent connection (keeps connection open)
+     * const client = new NATSBridge.NATSClient("nats://localhost:4222", true);
+     * await client.connect();
+     * await NATSBridge.smartsend("/test1", [["msg", "Hello", "text"]], { nats_connection: client, is_publish: false });
+     * await NATSBridge.publishMessage(client, "/test2", JSON.stringify({msg: "World"}), "trace-id");
+     * // Connection remains open for more publishes
+     * await client.close();
     */
    NATSClient,

+    /**
+     * Connection pool for managing multiple NATS connections
+     * Useful for applications with multiple concurrent publishers
+     * 
+     * @example
+     * const pool = new NATSBridge.NATSConnectionPool("nats://localhost:4222", 10);
+     * const client = await pool.acquire();
+     * await NATSBridge.smartsend("/test", [["msg", "Hello", "text"]], { nats_connection: client });
+     * pool.release(client);
+     * await pool.closeAll();
+     */
+    NATSConnectionPool,
+
    /**
     * Send data via NATS with automatic transport selection
     */
@@ -777,6 +908,19 @@ const NATSBridge = {
     */
    smartreceive,

+    /**
+     * Publish message to NATS
+     * 
+     * @example
+     * // Using a persistent connection
+     * const client = new NATSBridge.NATSClient("nats://localhost:4222", true);
+     * await client.connect();
+     * await NATSBridge.publishMessage(client, "/subject", JSON.stringify({msg: "Hello"}), "trace-id", false);
+     * // Connection stays open for more publishes
+     * await client.close();
+     */
+    publishMessage,
+
    /**
     * Upload data to plik server in one-shot mode
     */