2.3.0

changelog.md

@@ -1,5 +1,97 @@
 # Changelog
 
+## 2025-08-30 - 2.3.0 - feat(streaming)
+Add streaming support: chunked stream transfers, file send/receive, stream events and helpers
+
+- Implement chunked streaming protocol in IpcChannel (init / chunk / end / error / cancel messages)
+- Add sendStream, cancelOutgoingStream and cancelIncomingStream methods to IpcChannel
+- Expose high-level streaming API on client: sendStream, sendFile, cancelOutgoingStream, cancelIncomingStream
+- Expose high-level streaming API on server: sendStreamToClient, sendFileToClient, cancelIncomingStreamFromClient, cancelOutgoingStreamToClient
+- Emit 'stream' events from channels/servers/clients with (info, readable) where info includes streamId, meta, headers and clientId
+- Add maxConcurrentStreams option (default 32) and enforce concurrent stream limits for incoming/outgoing
+- Add SmartIpc.pipeStreamToFile helper to persist incoming streams to disk
+- Export stream in smartipc.plugins and update README with streaming usage and examples
+- Add comprehensive streaming tests (test/test.streaming.ts) covering large payloads, file transfer, cancellation and concurrency limits
+
+## 2025-08-29 - 2.2.2 - fix(ipc)
+Propagate per-client disconnects, add proper routing for targeted messages, and remove unused node-ipc deps
+
+- Forward per-client 'clientDisconnected' events from transports up through IpcChannel and IpcServer so higher layers can react and clean up state.
+- IpcChannel re-emits 'clientDisconnected' and allows registering handlers for it.
+- IpcServer now listens for 'clientDisconnected' to cleanup topic subscriptions, remove clients from the map, and emit 'clientDisconnect'.
+- sendToClient injects the target clientId into headers so transports can route messages to the correct socket instead of broadcasting.
+- broadcast and broadcastTo delegate to sendToClient to ensure messages are routed to intended recipients and errors are attributed to the correct client.
+- Transports now emit 'clientDisconnected' with the clientId when known.
+- package.json: removed unused node-ipc and @types/node-ipc dependencies (dependency cleanup).
+
+## 2025-08-29 - 2.2.1 - fix(tests)
+Remove redundant manual topic handlers from tests and rely on server built-in pub/sub
+
+- Removed manual server.onMessage('__subscribe__') and server.onMessage('__publish__') handlers from test/test.ts
+- Tests now rely on the server's built-in publish/subscribe behavior: clients publish directly and subscribers receive messages
+- Test code simplified without changing public API or runtime behavior
+
+## 2025-08-29 - 2.2.0 - feat(ipcclient)
+Add clientOnly mode to prevent clients from auto-starting servers and improve registration/reconnect behavior
+
+- Introduce a clientOnly option on transports and clients, and support SMARTIPC_CLIENT_ONLY=1 env override to prevent a client from auto-starting a server when connect() encounters ECONNREFUSED/ENOENT.
+- Update UnixSocketTransport/TcpTransport connect behavior: if clientOnly (or env override) is enabled, reject connect with a descriptive error instead of starting a server (preserves backward compatibility when disabled).
+- Make SmartIpc.waitForServer use clientOnly probing to avoid accidental server creation during readiness checks.
+- Refactor IpcClient registration flow: extract attemptRegistrationInternal, set didRegisterOnce flag, and automatically re-register on reconnects when previously registered.
+- Add and update tests to cover clientOnly behavior, SMARTIPC_CLIENT_ONLY env enforcement, temporary socket paths and automatic cleanup, and other reliability improvements.
+- Update README with a new 'Client-Only Mode' section documenting the option, env override, and examples.
+
+## 2025-08-28 - 2.1.3 - fix(classes.ipcchannel)
+Normalize heartbeatThrowOnTimeout option parsing and allow registering 'heartbeatTimeout' via IpcChannel.on
+
+- Normalize heartbeatThrowOnTimeout to boolean (accepts 'true'/'false' strings and other truthy/falsey values) to be defensive for JS consumers
+- Expose 'heartbeatTimeout' as a special channel event so handlers registered via IpcChannel.on('heartbeatTimeout', ...) will be called
+
+## 2025-08-26 - 2.1.2 - fix(core)
+Improve heartbeat handling and transport routing; forward heartbeat timeout events; include clientId routing and probe improvements
+
+- IpcChannel: add heartbeatInitialGracePeriod handling — delay heartbeat timeout checks until the grace period elapses and use a minimum check interval (>= 1000ms)
+- IpcChannel: add heartbeatGraceTimer and ensure stopHeartbeat clears the grace timer to avoid repeated events
+- IpcChannel / Client / Server: forward heartbeatTimeout events instead of only throwing when configured (heartbeatThrowOnTimeout = false) so consumers can handle timeouts via events
+- IpcClient: include clientId in registration request headers to enable proper routing on the server/transport side
+- UnixSocketTransport: track socket <-> clientId mappings, clean them up on socket close, and update mappings when __register__ or messages containing clientId are received
+- UnixSocketTransport: route messages to a specific client when headers.clientId is present (fallback to broadcasting when no target is found), and emit both clientMessage and message for parsed client messages
+- ts/index.waitForServer: use SmartIpc.createClient for probing, shorten probe register timeout, and use a slightly longer retry delay between probes for stability
+
+## 2025-08-25 - 2.1.1 - fix(readme)
+Update README: expand docs, examples, server readiness, heartbeat, and testing utilities
+
+- Rewrite introduction and overall tone to emphasize zero-dependency, reliability, and TypeScript support
+- Replace several Quick Start examples to use socketPath and show autoCleanupSocketFile usage
+- Add Server readiness detection docs and SmartIpc.waitForServer example
+- Document smart connection retry options (connectRetry) and registerTimeoutMs usage
+- Clarify heartbeat configuration and add heartbeatThrowOnTimeout option to emit events instead of throwing
+- Add sections for automatic socket cleanup, broadcasting, testing utilities (waitForServer, spawnAndConnect), and metrics
+- Various formatting and copy improvements throughout README
+
+## 2025-08-25 - 2.1.0 - feat(core)
+Add heartbeat grace/timeout options, client retry/wait-for-ready, server readiness and socket cleanup, transport socket options, helper utilities, and tests
+
+- IpcChannel: add heartbeatInitialGracePeriodMs and heartbeatThrowOnTimeout; emit 'heartbeatTimeout' event when configured instead of throwing and disconnecting immediately.
+- IpcClient: add connectRetry configuration, registerTimeoutMs, waitForReady option and robust connect logic with exponential backoff and total timeout handling.
+- IpcServer: add start option readyWhen ('accepting'), isReady/getIsReady API, autoCleanupSocketFile and socketMode support for managing stale socket files and permissions.
+- Transports: support autoCleanupSocketFile and socketMode (cleanup stale socket files and set socket permissions where applicable).
+- SmartIpc: add waitForServer helper to wait until a server is ready and spawnAndConnect helper to spawn a server process and connect a client.
+- Tests: add comprehensive tests (test.improvements.ts and test.reliability.ts) covering readiness, socket cleanup, retries, heartbeat behavior, race conditions, multiple clients, and server restart scenarios.
+
+## 2025-08-25 - 2.0.3 - fix(ipc)
+Patch release prep: bump patch version and release minor fixes
+
+- No changes detected in the provided diff; repository files currently declare version 2.0.2.
+- Recommend a patch bump to 2.0.3 to prepare a new release (no breaking changes identified).
+
+## 2025-08-24 - 2.0.2 - fix(packaging)
+Update package metadata: add exports, mark package public; clean up README contributing section
+
+- Add an exports entry in package.json pointing to ./dist_ts/index.js for proper ESM exports resolution
+- Mark package as public (private: false) and remove legacy main/typings fields
+- Remove the Contributing section and example contributor workflow from README
+
 ## 2025-08-24 - 2.0.1 - fix(npm)
 Remove .npmrc to avoid committing npm registry configuration
 
@@ -31,3 +123,10 @@ Initial release and a series of patch fixes to core components.
 
 - 1.0.1: initial release.
 - 1.0.2 → 1.0.7: a sequence of small core fixes and maintenance updates (repeated "fix(core): update" commits).
+## 2025-08-29 - 2.1.4 - feat(transports)
+Add client-only mode to prevent unintended server auto-start in Unix/NamedPipe transports; safer probing
+
+- Add `clientOnly?: boolean` to transport options; when true (or `SMARTIPC_CLIENT_ONLY=1`), a client will fail fast on `ECONNREFUSED`/`ENOENT` instead of auto-starting a server.
+- Update `SmartIpc.waitForServer()` to probe with `clientOnly: true` to avoid races during readiness checks.
+- Extend tests to cover option and env override; update core test to use unique socket path and auto-cleanup.
+- Docs: add README section for client-only mode.

package.json

@@ -1,10 +1,11 @@
 {
   "name": "@push.rocks/smartipc",
-  "version": "2.0.1",
+  "version": "2.3.0",
   "private": false,
   "description": "A library for node inter process communication, providing an easy-to-use API for IPC.",
-  "main": "dist/index.js",
+  "exports": {
-  "typings": "dist/index.d.ts",
+    ".": "./dist_ts/index.js"
+  },
   "author": "Lossless GmbH",
   "license": "MIT",
   "scripts": {
@@ -23,9 +24,7 @@
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     "@push.rocks/smartdelay": "^3.0.1",
-    "@push.rocks/smartrx": "^3.0.10",
+    "@push.rocks/smartrx": "^3.0.10"
-    "@types/node-ipc": "^9.1.1",
-    "node-ipc": "^12.0.0"
   },
   "keywords": [
     "IPC",

pnpm-lock.yaml

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@@ -3955,26 +3869,14 @@ packages:
     resolution: {integrity: sha512-TEU+nJVUUnA4CYJFLvK5X9AOeH4KvDvhIfm0vV1GaQRtchnG0hgK5p8hw/xjv8cunWYCsiPCSDzObPyhEwq3KQ==}
     engines: {node: '>=0.4.0'}
 
-  xtend@4.0.2:
-    resolution: {integrity: sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ==}
-    engines: {node: '>=0.4'}
-
   y18n@5.0.8:
     resolution: {integrity: sha512-0pfFzegeDWJHJIAmTLRP2DwHjdF5s7jo9tuztdQxAhINCdvS+3nGINqPd00AphqJR/0LhANUS6/+7SCb98YOfA==}
     engines: {node: '>=10'}
 
-  yargs-parser@20.2.9:
-    resolution: {integrity: sha512-y11nGElTIV+CT3Zv9t7VKl+Q3hTQoT9a1Qzezhhl6Rp21gJ/IVTW7Z3y9EWXhuUBC2Shnf+DX0antecpAwSP8w==}
-    engines: {node: '>=10'}
-
   yargs-parser@21.1.1:
     resolution: {integrity: sha512-tVpsJW7DdjecAiFpbIB1e3qxIQsE6NoPc5/eTdrbbIC4h0LVsWhnoa3g+m2HclBIujHzsxZ4VJVA+GUuc2/LBw==}
     engines: {node: '>=12'}
 
-  yargs@16.2.0:
-    resolution: {integrity: sha512-D1mvvtDG0L5ft/jGWkLpG1+m0eQxOfaBvTNELraWj22wSVUMWxZUvYgJYcKh6jGGIkJFhH4IZPQhR4TKpc8mBw==}
-    engines: {node: '>=10'}
-
   yargs@17.7.2:
     resolution: {integrity: sha512-7dSzzRQ++CKnNI/krKnYRV7JKKPUXMEh61soaHKg9mrWEhzFWhFnxPxGl+69cD1Ou63C13NUPCnmIcrvqCuM6w==}
     engines: {node: '>=12'}
@@ -6988,10 +6890,6 @@ snapshots:
     dependencies:
       '@types/node': 22.13.8
 
-  '@types/node-ipc@9.2.3':
-    dependencies:
-      '@types/node': 22.13.8
-
   '@types/node@22.13.8':
     dependencies:
       undici-types: 6.20.0
@@ -7287,12 +7185,6 @@ snapshots:
 
   clean-stack@1.3.0: {}
 
-  cliui@7.0.4:
-    dependencies:
-      string-width: 4.2.3
-      strip-ansi: 6.0.1
-      wrap-ansi: 7.0.0
-
   cliui@8.0.1:
     dependencies:
       string-width: 4.2.3
@@ -7372,18 +7264,6 @@ snapshots:
       depd: 2.0.0
       keygrip: 1.1.0
 
-  copyfiles@2.4.1:
-    dependencies:
-      glob: 7.2.3
-      minimatch: 3.1.2
-      mkdirp: 1.0.4
-      noms: 0.0.0
-      through2: 2.0.5
-      untildify: 4.0.0
-      yargs: 16.2.0
-
-  core-util-is@1.0.3: {}
-
   cors@2.8.5:
     dependencies:
       object-assign: 4.1.1
@@ -7502,8 +7382,6 @@ snapshots:
 
   eastasianwidth@0.2.0: {}
 
-  easy-stack@1.0.1: {}
-
   ee-first@1.1.1: {}
 
   emoji-regex@8.0.0: {}
@@ -7630,11 +7508,6 @@ snapshots:
 
   etag@1.8.1: {}
 
-  event-pubsub@5.0.3:
-    dependencies:
-      copyfiles: 2.4.1
-      strong-type: 0.1.6
-
   eventemitter3@4.0.7: {}
 
   express-force-ssl@0.3.2:
@@ -8107,10 +7980,6 @@ snapshots:
     dependencies:
       is-docker: 2.2.1
 
-  isarray@0.0.1: {}
-
-  isarray@1.0.0: {}
-
   isexe@2.0.0: {}
 
   isexe@3.1.1: {}
@@ -8123,12 +7992,6 @@ snapshots:
 
   js-base64@3.7.7: {}
 
-  js-message@1.0.7: {}
-
-  js-queue@2.0.2:
-    dependencies:
-      easy-stack: 1.0.1
-
   js-tokens@4.0.0: {}
 
   js-yaml@3.14.1:
@@ -8683,8 +8546,6 @@ snapshots:
 
   mitt@3.0.1: {}
 
-  mkdirp@1.0.4: {}
-
   mongodb-connection-string-url@3.0.2:
     dependencies:
       '@types/whatwg-url': 11.0.5
@@ -8759,18 +8620,6 @@ snapshots:
 
   node-forge@1.3.1: {}
 
-  node-ipc@12.0.0:
-    dependencies:
-      event-pubsub: 5.0.3
-      js-message: 1.0.7
-      js-queue: 2.0.2
-      strong-type: 1.1.0
-
-  noms@0.0.0:
-    dependencies:
-      inherits: 2.0.4
-      readable-stream: 1.0.34
-
   normalize-newline@4.1.0:
     dependencies:
       replace-buffer: 1.2.1
@@ -8928,8 +8777,6 @@ snapshots:
     dependencies:
       parse-ms: 4.0.0
 
-  process-nextick-args@2.0.1: {}
-
   progress@2.0.3: {}
 
   property-information@7.1.0: {}
@@ -9028,23 +8875,6 @@ snapshots:
       minimist: 1.2.8
       strip-json-comments: 2.0.1
 
-  readable-stream@1.0.34:
-    dependencies:
-      core-util-is: 1.0.3
-      inherits: 2.0.4
-      isarray: 0.0.1
-      string_decoder: 0.10.31
-
-  readable-stream@2.3.8:
-    dependencies:
-      core-util-is: 1.0.3
-      inherits: 2.0.4
-      isarray: 1.0.0
-      process-nextick-args: 2.0.1
-      safe-buffer: 5.1.2
-      string_decoder: 1.1.1
-      util-deprecate: 1.0.2
-
   readable-stream@3.6.2:
     dependencies:
       inherits: 2.0.4
@@ -9183,8 +9013,6 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  safe-buffer@5.1.2: {}
-
   safe-buffer@5.2.1: {}
 
   safe-regex-test@1.1.0:
@@ -9395,12 +9223,6 @@ snapshots:
       emoji-regex: 9.2.2
       strip-ansi: 7.1.0
 
-  string_decoder@0.10.31: {}
-
-  string_decoder@1.1.1:
-    dependencies:
-      safe-buffer: 5.1.2
-
   string_decoder@1.3.0:
     dependencies:
       safe-buffer: 5.2.1
@@ -9428,10 +9250,6 @@ snapshots:
 
   strnum@2.1.1: {}
 
-  strong-type@0.1.6: {}
-
-  strong-type@1.1.0: {}
-
   strtok3@10.3.4:
     dependencies:
       '@tokenizer/token': 0.3.0
@@ -9490,11 +9308,6 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  through2@2.0.5:
-    dependencies:
-      readable-stream: 2.3.8
-      xtend: 4.0.2
-
   through2@4.0.2:
     dependencies:
       readable-stream: 3.6.2
@@ -9619,8 +9432,6 @@ snapshots:
 
   unpipe@1.0.0: {}
 
-  untildify@4.0.0: {}
-
   upper-case@1.1.3: {}
 
   url@0.11.4:
@@ -9719,24 +9530,10 @@ snapshots:
 
   xmlhttprequest-ssl@2.1.2: {}
 
-  xtend@4.0.2: {}
-
   y18n@5.0.8: {}
 
-  yargs-parser@20.2.9: {}
-
   yargs-parser@21.1.1: {}
 
-  yargs@16.2.0:
-    dependencies:
-      cliui: 7.0.4
-      escalade: 3.2.0
-      get-caller-file: 2.0.5
-      require-directory: 2.1.1
-      string-width: 4.2.3
-      y18n: 5.0.8
-      yargs-parser: 20.2.9
-
   yargs@17.7.2:
     dependencies:
       cliui: 8.0.1

readme.md

@@ -1,34 +1,34 @@
 # @push.rocks/smartipc 🚀
 
-**Lightning-fast, type-safe IPC for modern Node.js applications**
+**Rock-solid IPC for Node.js with zero dependencies**
 
 [![npm version](https://img.shields.io/npm/v/@push.rocks/smartipc.svg)](https://www.npmjs.com/package/@push.rocks/smartipc)
 [![TypeScript](https://img.shields.io/badge/TypeScript-5.x-blue.svg)](https://www.typescriptlang.org/)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](./license)
 
-SmartIPC is a production-grade Inter-Process Communication library that brings enterprise-level messaging patterns to Node.js. Built with TypeScript from the ground up, it offers zero-dependency native IPC with automatic reconnection, type-safe messaging, and built-in observability.
+SmartIPC delivers bulletproof Inter-Process Communication for Node.js applications. Built for real-world production use, it handles all the edge cases that make IPC tricky - automatic reconnection, race conditions, heartbeat monitoring, and clean shutdowns. All with **zero external dependencies** and full TypeScript support.
 
-## Why SmartIPC?
+## 🎯 Why SmartIPC?
 
-- **🎯 Zero External Dependencies** - Pure Node.js implementation using native `net` module
+- **Zero Dependencies** - Pure Node.js implementation using native modules
-- **🔒 Type-Safe** - Full TypeScript support with generics for compile-time safety
+- **Battle-tested Reliability** - Automatic reconnection, graceful degradation, and timeout handling
-- **🔄 Auto-Reconnect** - Built-in exponential backoff and circuit breaker patterns
+- **Type-Safe** - Full TypeScript support with generics for compile-time safety
-- **📊 Observable** - Real-time metrics and connection tracking
+- **CI/Test Ready** - Built-in helpers and race condition prevention for testing
-- **⚡ High Performance** - Length-prefixed framing, backpressure handling, and optimized buffers
+- **Observable** - Real-time metrics, connection tracking, and health monitoring
-- **🎭 Multiple Patterns** - Request/Response, Pub/Sub, and Fire-and-Forget messaging
+- **Multiple Patterns** - Request/Response, Pub/Sub, and Fire-and-Forget messaging
-- **🛡️ Production Ready** - Message size limits, heartbeat monitoring, and graceful shutdown
+- **Streaming Support** - Efficient, backpressure‑aware streaming for large data and files
 
-## Installation
+## 📦 Installation
 
 ```bash
+npm install @push.rocks/smartipc
+# or
 pnpm add @push.rocks/smartipc
 # or
-npm install @push.rocks/smartipc
+yarn add @push.rocks/smartipc
 ```
 
-## Quick Start
+## 🚀 Quick Start
-
-### Simple TCP Server & Client
 
 ```typescript
 import { SmartIpc } from '@push.rocks/smartipc';
@@ -36,34 +36,42 @@ import { SmartIpc } from '@push.rocks/smartipc';
 // Create a server
 const server = SmartIpc.createServer({
   id: 'my-service',
-  host: 'localhost',
+  socketPath: '/tmp/my-service.sock',
-  port: 9876
+  autoCleanupSocketFile: true  // Clean up stale sockets automatically
 });
 
 // Handle incoming messages
-server.onMessage('hello', async (data, clientId) => {
+server.onMessage('greet', async (data, clientId) => {
-  console.log(`Client ${clientId} says:`, data);
+  console.log(`Client ${clientId} says:`, data.message);
-  return { response: 'Hello back!' };
+  return { response: `Hello ${data.name}!` };
 });
 
-await server.start();
+// Start the server
+await server.start({ readyWhen: 'accepting' });  // Wait until fully ready
+console.log('Server is ready to accept connections! ✨');
 
 // Create a client
 const client = SmartIpc.createClient({
   id: 'my-service',
-  host: 'localhost', 
+  socketPath: '/tmp/my-service.sock',
-  port: 9876,
+  connectRetry: {
-  clientId: 'client-1'
+    enabled: true,
+    maxAttempts: 10
+  }
 });
 
+// Connect with automatic retry
 await client.connect();
 
-// Send a message and get response
+// Send a request and get a response
-const response = await client.request('hello', { message: 'Hi server!' });
+const response = await client.request('greet', { 
-console.log('Server responded:', response);
+  name: 'World',
+  message: 'Hi there!' 
+});
+console.log('Server said:', response.response);  // "Hello World!"
 ```
 
-## Core Concepts
+## 🎮 Core Concepts
 
 ### Transport Types
 
@@ -84,348 +92,505 @@ const unixServer = SmartIpc.createServer({
 });
 
 // Windows Named Pipe (Windows optimal)
-const pipeServer = SmartIpc.createServer({
+// Automatically used on Windows when socketPath is provided
+const windowsServer = SmartIpc.createServer({
   id: 'pipe-service',
-  pipeName: 'my-app-pipe'
+  socketPath: '\\\\.\\pipe\\my-app-pipe'
 });
 ```
 
 ### Message Patterns
 
 #### 🔥 Fire and Forget
-Fast, one-way messaging when you don't need a response:
+Send messages without waiting for a response:
 
 ```typescript
 // Server
 server.onMessage('log', (data, clientId) => {
-  console.log(`[${clientId}]:`, data.message);
+  console.log(`[${clientId}] ${data.level}:`, data.message);
-  // No return value needed
+  // No return needed
 });
 
 // Client
 await client.sendMessage('log', { 
+  level: 'info',
   message: 'User logged in',
   timestamp: Date.now()
 });
 ```
 
 #### 📞 Request/Response
-RPC-style communication with timeouts and type safety:
+RPC-style communication with type safety:
 
 ```typescript
-// Server - Define your handler with types
+interface UserRequest {
-interface CalculateRequest {
+  userId: string;
-  operation: 'add' | 'multiply';
+  fields?: string[];
-  values: number[];
 }
 
-interface CalculateResponse {
+interface UserResponse {
-  result: number;
+  id: string;
-  computedAt: number;
+  name: string;
+  email?: string;
+  createdAt: number;
 }
 
-server.onMessage<CalculateRequest, CalculateResponse>('calculate', async (data) => {
+// Server
-  const result = data.operation === 'add' 
+server.onMessage<UserRequest, UserResponse>('getUser', async (data) => {
-    ? data.values.reduce((a, b) => a + b, 0)
+  const user = await db.getUser(data.userId);
-    : data.values.reduce((a, b) => a * b, 1);
-    
   return {
-    result,
+    id: user.id,
-    computedAt: Date.now()
+    name: user.name,
+    email: data.fields?.includes('email') ? user.email : undefined,
+    createdAt: user.createdAt
   };
 });
 
-// Client - Type-safe request
+// Client - with timeout
-const response = await client.request<CalculateRequest, CalculateResponse>(
+const user = await client.request<UserRequest, UserResponse>(
-  'calculate',
+  'getUser',
-  { operation: 'add', values: [1, 2, 3, 4, 5] },
+  { userId: '123', fields: ['email'] },
   { timeout: 5000 }
 );
-
-console.log(`Sum is ${response.result}`);
 ```
 
 #### 📢 Pub/Sub Pattern
 Topic-based message broadcasting:
 
 ```typescript
-// Server automatically handles subscriptions
+// Subscribers
-const publisher = SmartIpc.createClient({
-  id: 'events-service',
-  clientId: 'publisher'
-});
-
 const subscriber1 = SmartIpc.createClient({
   id: 'events-service',
-  clientId: 'subscriber-1'
+  socketPath: '/tmp/events.sock'
 });
 
-const subscriber2 = SmartIpc.createClient({
+await subscriber1.connect();
-  id: 'events-service',
-  clientId: 'subscriber-2'
-});
-
-// Subscribe to topics
 await subscriber1.subscribe('user.login', (data) => {
   console.log('User logged in:', data);
 });
 
-await subscriber2.subscribe('user.*', (data) => {
+// Publisher
-  console.log('User event:', data);
+const publisher = SmartIpc.createClient({
+  id: 'events-service',
+  socketPath: '/tmp/events.sock'
 });
 
-// Publish events
+await publisher.connect();
 await publisher.publish('user.login', { 
   userId: '123',
+  ip: '192.168.1.1',
   timestamp: Date.now()
 });
 ```
 
-## Advanced Features
+## 💪 Advanced Features
 
-### 🔄 Auto-Reconnection with Exponential Backoff
+### 📦 Streaming Large Data & Files
 
-Clients automatically reconnect on connection loss:
+SmartIPC supports efficient, backpressure-aware streaming of large payloads using chunked messages. Streams work both directions and emit a high-level `stream` event for consumption.
+
+Client → Server streaming:
+
+```typescript
+// Server side: receive stream
+server.on('stream', async (info, readable) => {
+  if (info.meta?.type === 'file') {
+    console.log('Receiving file', info.meta.basename, 'from', info.clientId);
+  }
+  // Pipe to disk or process chunks
+  await SmartIpc.pipeStreamToFile(readable, '/tmp/incoming.bin');
+});
+
+// Client side: send a stream
+const readable = fs.createReadStream('/path/to/local.bin');
+await client.sendStream(readable, {
+  meta: { type: 'file', basename: 'local.bin' },
+  chunkSize: 64 * 1024 // optional, defaults to 64k
+});
+```
+
+Server → Client streaming:
+
+```typescript
+client.on('stream', async (info, readable) => {
+  console.log('Got stream from server', info.meta);
+  await SmartIpc.pipeStreamToFile(readable, '/tmp/from-server.bin');
+});
+
+await server.sendStreamToClient(client.getClientId(), fs.createReadStream('/path/server.bin'), {
+  meta: { type: 'file', basename: 'server.bin' }
+});
+```
+
+High-level helpers for files:
+
+```typescript
+// Client → Server
+await client.sendFile('/path/to/bigfile.iso');
+
+// Server → Client
+await server.sendFileToClient(clientId, '/path/to/backup.tar');
+
+// Save an incoming stream to a file (both sides)
+server.on('stream', async (info, readable) => {
+  await SmartIpc.pipeStreamToFile(readable, '/data/uploaded/' + info.meta?.basename);
+});
+```
+
+Events & metadata:
+
+- `channel/server/client` emit `stream` with `(info, readable)`
+- `info` contains: `streamId`, `meta` (your metadata, e.g., filename/size), `headers`, and `clientId` (if available)
+
+API summary:
+
+- Client: `sendStream(readable, opts)`, `sendFile(filePath, opts)`, `cancelOutgoingStream(id)`, `cancelIncomingStream(id)`
+- Server: `sendStreamToClient(clientId, readable, opts)`, `sendFileToClient(clientId, filePath, opts)`, `cancelIncomingStreamFromClient(clientId, id)`, `cancelOutgoingStreamToClient(clientId, id)`
+- Utility: `SmartIpc.pipeStreamToFile(readable, filePath)`
+
+Concurrency and cancelation:
+
+```typescript
+// Limit concurrent streams per connection
+const server = SmartIpc.createServer({
+  id: 'svc', socketPath: '/tmp/svc.sock', maxConcurrentStreams: 2
+});
+
+// Cancel a stream from the receiver side
+server.on('stream', (info, readable) => {
+  if (info.meta?.shouldCancel) {
+    (server as any).primaryChannel.cancelIncomingStream(info.streamId, { clientId: info.clientId });
+  }
+});
+```
+
+Notes:
+- Streaming uses chunked messages under the hood and respects socket backpressure.
+- Include `meta` to share context like filename/size; it’s delivered with the `stream` event.
+- Configure `maxConcurrentStreams` (default: 32) to guard resources.
+
+### 🏁 Server Readiness Detection
+
+Eliminate race conditions in tests and production:
+
+```typescript
+const server = SmartIpc.createServer({
+  id: 'my-service',
+  socketPath: '/tmp/my-service.sock',
+  autoCleanupSocketFile: true
+});
+
+// Option 1: Wait for full readiness
+await server.start({ readyWhen: 'accepting' });
+// Server is now FULLY ready to accept connections
+
+// Option 2: Use ready event
+server.on('ready', () => {
+  console.log('Server is ready!');
+  startClients();
+});
+
+await server.start();
+
+// Option 3: Check readiness state
+if (server.getIsReady()) {
+  console.log('Ready to rock! 🎸');
+}
+```
+
+### 🔄 Smart Connection Retry
+
+Never lose messages due to temporary connection issues:
 
 ```typescript
 const client = SmartIpc.createClient({
-  id: 'resilient-service',
+  id: 'resilient-client',
-  clientId: 'auto-reconnect-client',
+  socketPath: '/tmp/service.sock',
-  reconnect: {
+  connectRetry: {
     enabled: true,
-    initialDelay: 1000,      // Start with 1 second
+    initialDelay: 100,      // Start with 100ms
-    maxDelay: 30000,         // Cap at 30 seconds
+    maxDelay: 1500,         // Cap at 1.5 seconds
-    factor: 2,               // Double each time
+    maxAttempts: 20,        // Try 20 times
-    maxAttempts: Infinity    // Keep trying forever
+    totalTimeout: 15000     // Give up after 15 seconds total
-  }
+  },
+  registerTimeoutMs: 8000   // Registration handshake timeout
 });
 
-// Monitor connection state
+// Will retry automatically if server isn't ready yet
-client.on('connected', () => console.log('Connected! 🟢'));
+await client.connect({ 
-client.on('disconnected', () => console.log('Connection lost! 🔴'));
+  waitForReady: true,       // Wait for server to exist
-client.on('reconnecting', (attempt) => console.log(`Reconnecting... Attempt ${attempt} 🟡`));
+  waitTimeout: 10000        // Wait up to 10 seconds
+});
 ```
 
-### 💓 Heartbeat Monitoring
+### 🛑 Client-Only Mode (No Auto-Start)
 
-Keep connections alive and detect failures quickly:
+In some setups (CLI + long-running daemon), you want clients to fail fast when no server is available, rather than implicitly becoming the server. Enable client-only mode to prevent the “client becomes server” fallback for Unix domain sockets and Windows named pipes.
+
+```typescript
+// Strict client that never auto-starts a server on connect failure
+const client = SmartIpc.createClient({
+  id: 'my-service',
+  socketPath: '/tmp/my-service.sock',
+  clientId: 'my-cli',
+  clientOnly: true,                 // NEW: disable auto-start fallback
+  connectRetry: { enabled: false }  // optional: fail fast
+});
+
+try {
+  await client.connect();
+} catch (err) {
+  // With clientOnly: true, errors become descriptive
+  // e.g. "Server not available (ENOENT); clientOnly prevents auto-start"
+  console.error(err.message);
+}
+```
+
+- Default: `clientOnly` is `false` to preserve backward compatibility.
+- Env override: set `SMARTIPC_CLIENT_ONLY=1` to enforce client-only behavior without code changes.
+- Note: `SmartIpc.waitForServer()` internally uses `clientOnly: true` for safe probing.
+
+### 💓 Graceful Heartbeat Monitoring
+
+Keep connections alive without crashing on timeouts:
 
 ```typescript
 const server = SmartIpc.createServer({
   id: 'monitored-service',
-  heartbeat: {
+  socketPath: '/tmp/monitored.sock',
-    enabled: true,
+  heartbeat: true,
-    interval: 5000,      // Send heartbeat every 5 seconds
+  heartbeatInterval: 3000,
-    timeout: 15000       // Consider dead after 15 seconds
+  heartbeatTimeout: 10000,
-  }
+  heartbeatInitialGracePeriodMs: 5000,    // Grace period for startup
+  heartbeatThrowOnTimeout: false           // Emit event instead of throwing
 });
 
-// Clients automatically respond to heartbeats
+server.on('heartbeatTimeout', (clientId) => {
+  console.log(`Client ${clientId} heartbeat timeout - will handle gracefully`);
+});
+
+// Client configuration
 const client = SmartIpc.createClient({
   id: 'monitored-service',
-  clientId: 'heartbeat-client',
+  socketPath: '/tmp/monitored.sock',
-  heartbeat: true  // Enable heartbeat responses
+  heartbeat: true,
+  heartbeatInterval: 3000,
+  heartbeatTimeout: 10000,
+  heartbeatInitialGracePeriodMs: 5000,
+  heartbeatThrowOnTimeout: false
+});
+
+client.on('heartbeatTimeout', () => {
+  console.log('Heartbeat timeout detected, reconnecting...');
+  // Handle reconnection logic
 });
 ```
 
-### 📊 Real-time Metrics & Observability
+### 🧹 Automatic Socket Cleanup
 
-Track performance and connection health:
+Never worry about stale socket files:
 
 ```typescript
-// Server metrics
+const server = SmartIpc.createServer({
+  id: 'clean-service',
+  socketPath: '/tmp/service.sock',
+  autoCleanupSocketFile: true,    // Remove stale socket on start
+  socketMode: 0o600               // Set socket permissions (Unix only)
+});
+
+// Socket file will be cleaned up automatically on start
+await server.start();
+```
+
+### 📊 Real-time Metrics
+
+Monitor your IPC performance:
+
+```typescript
+// Server stats
 const serverStats = server.getStats();
 console.log({
   isRunning: serverStats.isRunning,
   connectedClients: serverStats.connectedClients,
   totalConnections: serverStats.totalConnections,
-  uptime: serverStats.uptime,
   metrics: {
     messagesSent: serverStats.metrics.messagesSent,
     messagesReceived: serverStats.metrics.messagesReceived,
-    bytesSent: serverStats.metrics.bytesSent,
-    bytesReceived: serverStats.metrics.bytesReceived,
     errors: serverStats.metrics.errors
   }
 });
 
-// Client metrics
+// Client stats
 const clientStats = client.getStats();
 console.log({
   connected: clientStats.connected,
   reconnectAttempts: clientStats.reconnectAttempts,
-  lastActivity: clientStats.lastActivity,
   metrics: clientStats.metrics
 });
 
-// Track specific clients on server
+// Get specific client info
-const clientInfo = server.getClientInfo('client-1');
+const clientInfo = server.getClientInfo('client-123');
 console.log({
-  clientId: clientInfo.clientId,
+  connectedAt: new Date(clientInfo.connectedAt),
-  metadata: clientInfo.metadata,
+  lastActivity: new Date(clientInfo.lastActivity),
-  connectedAt: clientInfo.connectedAt,
+  metadata: clientInfo.metadata
-  lastActivity: clientInfo.lastActivity,
-  subscriptions: clientInfo.subscriptions
 });
 ```
 
-### 🛡️ Security & Limits
+### 🎯 Broadcasting
 
-Protect against malicious or misbehaving clients:
+Send messages to multiple clients:
-
-```typescript
-const secureServer = SmartIpc.createServer({
-  id: 'secure-service',
-  maxMessageSize: 10 * 1024 * 1024,  // 10MB max message size
-  maxConnections: 100,                // Limit concurrent connections
-  connectionTimeout: 60000,            // Drop idle connections after 1 minute
-  
-  // Authentication (coming soon)
-  auth: {
-    required: true,
-    validator: async (token) => {
-      // Validate auth token
-      return validateToken(token);
-    }
-  }
-});
-
-// Rate limiting per client
-secureServer.use(rateLimitMiddleware({
-  windowMs: 60000,  // 1 minute window
-  max: 100          // 100 requests per window
-}));
-```
-
-### 🎯 Broadcast to Specific Clients
-
-Send targeted messages:
 
 ```typescript
 // Broadcast to all connected clients
-server.broadcast('system-alert', { 
+await server.broadcast('announcement', { 
-  message: 'Maintenance in 5 minutes'
+  message: 'Server will restart in 5 minutes',
+  severity: 'warning'
 });
 
-// Send to specific client
+// Send to specific clients
-server.sendToClient('client-1', 'personal-message', {
+await server.broadcastTo(
-  content: 'This is just for you'
+  ['client-1', 'client-2'],
-});
+  'private-message',
+  { content: 'This is just for you two' }
+);
 
-// Send to multiple specific clients
+// Send to one client
-server.sendToClients(['client-1', 'client-2'], 'group-message', {
+await server.sendToClient('client-1', 'direct', {
-  content: 'Group notification'
+  data: 'Personal message'
 });
-
-// Get all connected client IDs
-const clients = server.getConnectedClients();
-console.log('Connected clients:', clients);
 ```
 
-## Error Handling
+## 🧪 Testing Utilities
 
-Comprehensive error handling with typed errors:
+SmartIPC includes powerful helpers for testing:
+
+### Wait for Server
 
 ```typescript
-import { IpcError, ConnectionError, TimeoutError } from '@push.rocks/smartipc';
+import { SmartIpc } from '@push.rocks/smartipc';
 
-// Client error handling
+// Start your server in another process
+const serverProcess = spawn('node', ['server.js']);
+
+// Wait for it to be ready
+await SmartIpc.waitForServer({
+  socketPath: '/tmp/test.sock',
+  timeoutMs: 10000
+});
+
+// Now safe to connect clients
+const client = SmartIpc.createClient({
+  id: 'test-client',
+  socketPath: '/tmp/test.sock'
+});
+await client.connect();
+```
+
+### Spawn and Connect
+
+```typescript
+// Helper that spawns a server and connects a client
+const { client, serverProcess } = await SmartIpc.spawnAndConnect({
+  serverScript: './server.js',
+  socketPath: '/tmp/test.sock',
+  clientId: 'test-client',
+  connectRetry: {
+    enabled: true,
+    maxAttempts: 10
+  }
+});
+
+// Use the client
+const response = await client.request('ping', {});
+
+// Cleanup
+await client.disconnect();
+serverProcess.kill();
+```
+
+## 🎭 Event Handling
+
+SmartIPC provides comprehensive event emitters:
+
+```typescript
+// Server events
+server.on('start', () => console.log('Server started'));
+server.on('ready', () => console.log('Server ready for connections'));
+server.on('clientConnect', (clientId, metadata) => {
+  console.log(`Client ${clientId} connected with metadata:`, metadata);
+});
+server.on('clientDisconnect', (clientId) => {
+  console.log(`Client ${clientId} disconnected`);
+});
+server.on('error', (error, clientId) => {
+  console.error(`Error from ${clientId}:`, error);
+});
+
+// Client events  
+client.on('connect', () => console.log('Connected to server'));
+client.on('disconnect', () => console.log('Disconnected from server'));
+client.on('reconnecting', (attempt) => {
+  console.log(`Reconnection attempt ${attempt}`);
+});
 client.on('error', (error) => {
-  if (error instanceof ConnectionError) {
+  console.error('Client error:', error);
-    console.error('Connection failed:', error.message);
+});
-  } else if (error instanceof TimeoutError) {
+client.on('heartbeatTimeout', (error) => {
-    console.error('Request timed out:', error.message);
+  console.warn('Heartbeat timeout:', error);
+});
+```
+
+## 🛡️ Error Handling
+
+Robust error handling with detailed error information:
+
+```typescript
+// Client-side error handling
+try {
+  const response = await client.request('riskyOperation', data, {
+    timeout: 5000
+  });
+} catch (error) {
+  if (error.message.includes('timeout')) {
+    console.error('Request timed out');
+  } else if (error.message.includes('Failed to register')) {
+    console.error('Could not register with server');
   } else {
     console.error('Unknown error:', error);
   }
-});
-
-// Server error handling
-server.on('client-error', (clientId, error) => {
-  console.error(`Client ${clientId} error:`, error);
-  
-  // Optionally disconnect misbehaving clients
-  if (error.code === 'INVALID_MESSAGE') {
-    server.disconnectClient(clientId);
-  }
-});
-
-// Request with error handling
-try {
-  const response = await client.request('risky-operation', data, {
-    timeout: 5000,
-    retries: 3
-  });
-} catch (error) {
-  if (error instanceof TimeoutError) {
-    // Handle timeout
-  } else {
-    // Handle other errors
-  }
 }
-```
 
-## Testing
+// Server-side error boundaries
-
+server.onMessage('process', async (data, clientId) => {
-SmartIPC includes comprehensive testing utilities:
+  try {
-
+    return await riskyProcessing(data);
-```typescript
+  } catch (error) {
-import { createTestServer, createTestClient } from '@push.rocks/smartipc/testing';
+    console.error(`Processing failed for ${clientId}:`, error);
-
+    throw error;  // Will be sent back to client as error
-describe('My IPC integration', () => {
+  }
-  let server, client;
-  
-  beforeEach(async () => {
-    server = await createTestServer();
-    client = await createTestClient(server);
-  });
-  
-  afterEach(async () => {
-    await client.disconnect();
-    await server.stop();
-  });
-  
-  it('should handle messages', async () => {
-    server.onMessage('test', (data) => ({ echo: data }));
-    
-    const response = await client.request('test', { value: 42 });
-    expect(response.echo.value).toBe(42);
-  });
 });
 ```
 
-## Performance Benchmarks
+## 🏗️ Architecture
 
-SmartIPC has been optimized for high throughput and low latency:
+SmartIPC uses a clean, layered architecture:
-
-| Transport | Messages/sec | Avg Latency | Use Case |
-|-----------|-------------|-------------|----------|
-| Unix Socket | 150,000+ | < 0.1ms | Local high-performance IPC |
-| TCP (localhost) | 100,000+ | < 0.2ms | Local network-capable IPC |
-| TCP (network) | 50,000+ | < 1ms | Distributed systems |
-| Named Pipe | 120,000+ | < 0.15ms | Windows local IPC |
-
-*Benchmarked on modern hardware with 1KB message payloads*
-
-## Architecture
-
-SmartIPC uses a layered architecture for maximum flexibility:
 
 ```
 ┌─────────────────────────────────────────┐
-│          Application Layer              │
+│          Your Application               │
-│   (Your business logic and handlers)    │
+│        (Business logic)                 │
 └─────────────────────────────────────────┘
                    ↕
 ┌─────────────────────────────────────────┐
-│          IPC Client / Server            │
+│         IpcServer / IpcClient           │
-│   (High-level API, patterns, routing)   │
+│   (High-level API, Message routing)     │
 └─────────────────────────────────────────┘
                    ↕
 ┌─────────────────────────────────────────┐
-│            IPC Channel                  │
+│            IpcChannel                   │
-│  (Connection management, reconnection,  │
+│  (Connection management, Heartbeat,     │
-│   heartbeat, request/response)          │
+│   Reconnection, Request/Response)       │
 └─────────────────────────────────────────┘
                    ↕
 ┌─────────────────────────────────────────┐
@@ -435,43 +600,94 @@ SmartIPC uses a layered architecture for maximum flexibility:
 └─────────────────────────────────────────┘
 ```
 
-## Comparison with Alternatives
+## 🎯 Common Use Cases
 
-| Feature | SmartIPC | node-ipc | zeromq | |
+### Microservices Communication
-|---------|----------|----------|---------|--|
+```typescript
-| Zero Dependencies | ✅ | ❌ | ❌ | |
+// API Gateway
-| TypeScript Native | ✅ | ❌ | ❌ | |
+const gateway = SmartIpc.createServer({
-| Auto-Reconnect | ✅ | ⚠️ | ✅ | |
+  id: 'api-gateway',
-| Request/Response | ✅ | ⚠️ | ✅ | |
+  socketPath: '/tmp/gateway.sock'
-| Pub/Sub | ✅ | ❌ | ✅ | |
+});
-| Built-in Metrics | ✅ | ❌ | ❌ | |
-| Heartbeat | ✅ | ❌ | ✅ | |
-| Message Size Limits | ✅ | ❌ | ✅ | |
-| Type Safety | ✅ | ❌ | ❌ | |
 
-## Contributing
+// User Service
+const userService = SmartIpc.createClient({
+  id: 'api-gateway',
+  socketPath: '/tmp/gateway.sock',
+  clientId: 'user-service'
+});
 
-We welcome contributions! Please see our [Contributing Guide](CONTRIBUTING.md) for details.
+// Order Service  
-
+const orderService = SmartIpc.createClient({
-```bash
+  id: 'api-gateway',
-# Clone the repository
+  socketPath: '/tmp/gateway.sock',
-git clone https://code.foss.global/push.rocks/smartipc.git
+  clientId: 'order-service'
-
+});
-# Install dependencies
-pnpm install
-
-# Run tests
-pnpm test
-
-# Build
-pnpm build
 ```
 
-## Support
+### Worker Process Management
+```typescript
+// Main process
+const server = SmartIpc.createServer({
+  id: 'main',
+  socketPath: '/tmp/workers.sock'
+});
 
-- 📖 [Documentation](https://code.foss.global/push.rocks/smartipc)
+server.onMessage('job-complete', (result, workerId) => {
-- 🐛 [Issue Tracker](https://code.foss.global/push.rocks/smartipc/issues)
+  console.log(`Worker ${workerId} completed job:`, result);
-- 💬 [Discussions](https://code.foss.global/push.rocks/smartipc/discussions)
+});
+
+// Worker process
+const worker = SmartIpc.createClient({
+  id: 'main',
+  socketPath: '/tmp/workers.sock',
+  clientId: `worker-${process.pid}`
+});
+
+await worker.sendMessage('job-complete', {
+  jobId: '123',
+  result: processedData
+});
+```
+
+### Real-time Event Distribution
+```typescript
+// Event bus
+const eventBus = SmartIpc.createServer({
+  id: 'event-bus',
+  socketPath: '/tmp/events.sock'
+});
+
+// Services subscribe to events
+const analyticsService = SmartIpc.createClient({
+  id: 'event-bus',
+  socketPath: '/tmp/events.sock'
+});
+
+await analyticsService.subscribe('user.*', (event) => {
+  trackEvent(event);
+});
+```
+
+## 📈 Performance
+
+SmartIPC is optimized for high throughput and low latency:
+
+| Transport | Messages/sec | Avg Latency | Use Case |
+|-----------|-------------|-------------|----------|
+| Unix Socket | 150,000+ | < 0.1ms | Local high-performance IPC (Linux/macOS) |
+| Named Pipe | 120,000+ | < 0.15ms | Windows local IPC |
+| TCP (localhost) | 100,000+ | < 0.2ms | Local network-capable IPC |
+| TCP (network) | 50,000+ | < 1ms | Distributed systems |
+
+- **Memory efficient**: Streaming support for large payloads
+- **CPU efficient**: Event-driven, non-blocking I/O
+
+## 🔧 Requirements
+
+- Node.js >= 14.x
+- TypeScript >= 4.x (for development)
+- Unix-like OS (Linux, macOS) or Windows
 
 ## License and Legal Information
 
@@ -491,7 +707,3 @@ Registered at District court Bremen HRB 35230 HB, Germany
 For any legal inquiries or if you require further information, please contact us via email at hello@task.vc.
 
 By using this repository, you acknowledge that you have read this section, agree to comply with its terms, and understand that the licensing of the code does not imply endorsement by Task Venture Capital GmbH of any derivative works.
-
----
-
-**Built with ❤️ by Task Venture Capital GmbH**

test/test.improvements.ts

@@ -0,0 +1,259 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartipc from '../ts/index.js';
+import * as path from 'path';
+import * as fs from 'fs';
+import * as os from 'os';
+
+const testSocketPath = path.join(os.tmpdir(), `test-ipc-improvements-${Date.now()}.sock`);
+
+// Test 1: Server Readiness API
+tap.test('Server readiness API should emit ready event', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable heartbeat for this test
+  });
+
+  let readyEventFired = false;
+  server.on('ready', () => {
+    readyEventFired = true;
+  });
+
+  await server.start({ readyWhen: 'accepting' });
+  
+  expect(readyEventFired).toBeTrue();
+  expect(server.getIsReady()).toBeTrue();
+
+  await server.stop();
+});
+
+// Test 2: Automatic Socket Cleanup
+tap.test('Should cleanup stale socket file automatically', async () => {
+  // Create a stale socket file
+  fs.writeFileSync(testSocketPath, '');
+  expect(fs.existsSync(testSocketPath)).toBeTrue();
+
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable heartbeat for this test
+  });
+
+  // Should clean up and start successfully
+  await server.start();
+  expect(server.getIsReady()).toBeTrue();
+  
+  await server.stop();
+});
+
+// Test 3: Basic Connection with New Options
+tap.test('Client should connect with basic configuration', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable heartbeat for this test
+  });
+
+  await server.start({ readyWhen: 'accepting' });
+  
+  // Wait for server to be fully ready
+  await new Promise(resolve => setTimeout(resolve, 200));
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    clientId: 'test-client',
+    registerTimeoutMs: 10000  // Longer timeout
+  });
+
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+// Test 4: Heartbeat Configuration Without Throwing
+tap.test('Heartbeat should use event mode instead of throwing', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable server heartbeat for this test
+  });
+
+  // Add error handler to prevent unhandled errors
+  server.on('error', () => {});
+
+  await server.start({ readyWhen: 'accepting' });
+  await new Promise(resolve => setTimeout(resolve, 200));
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    clientId: 'heartbeat-client',
+    heartbeat: true,
+    heartbeatInterval: 100,
+    heartbeatTimeout: 300,
+    heartbeatInitialGracePeriodMs: 1000,
+    heartbeatThrowOnTimeout: false  // Don't throw, emit event
+  });
+
+  let heartbeatTimeoutFired = false;
+  client.on('heartbeatTimeout', () => {
+    heartbeatTimeoutFired = true;
+  });
+  
+  client.on('error', () => {});
+
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  // Wait a bit but within grace period
+  await new Promise(resolve => setTimeout(resolve, 500));
+  
+  // Should still be connected, no timeout during grace period
+  expect(heartbeatTimeoutFired).toBeFalse();
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+// Test 5: Wait for Server Helper
+tap.test('waitForServer should detect when server becomes ready', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable heartbeat for this test
+  });
+
+  // Start server after delay
+  setTimeout(async () => {
+    await server.start();
+  }, 200);
+
+  // Wait for server should succeed
+  await smartipc.SmartIpc.waitForServer({
+    socketPath: testSocketPath,
+    timeoutMs: 3000
+  });
+
+  // Server should be ready now
+  const client = smartipc.SmartIpc.createClient({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    clientId: 'wait-test-client'
+  });
+  
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+// Test 6: Connect Retry Configuration
+tap.test('Client retry should work with delayed server', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: false  // Disable heartbeat for this test
+  });
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    clientId: 'retry-client',
+    connectRetry: {
+      enabled: true,
+      initialDelay: 100,
+      maxDelay: 500,
+      maxAttempts: 10,
+      totalTimeout: 5000
+    }
+  });
+
+  // Start server after a delay
+  setTimeout(async () => {
+    await server.start({ readyWhen: 'accepting' });
+  }, 300);
+
+  // Client should retry and eventually connect
+  await client.connect({ waitForReady: true, waitTimeout: 5000 });
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+// Test 7: clientOnly prevents client from auto-starting a server
+tap.test('clientOnly should prevent auto-start and fail fast', async () => {
+  const uniqueSocketPath = path.join(os.tmpdir(), `smartipc-clientonly-${Date.now()}.sock`);
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'clientonly-test',
+    socketPath: uniqueSocketPath,
+    clientId: 'co-client-1',
+    clientOnly: true,
+    connectRetry: { enabled: false }
+  });
+
+  let failed = false;
+  try {
+    await client.connect();
+  } catch (err: any) {
+    failed = true;
+    expect(err.message).toContain('clientOnly prevents auto-start');
+  }
+  expect(failed).toBeTrue();
+  // Ensure no server-side socket was created
+  expect(fs.existsSync(uniqueSocketPath)).toBeFalse();
+});
+
+// Test 8: env SMARTIPC_CLIENT_ONLY enforces clientOnly behavior
+tap.test('SMARTIPC_CLIENT_ONLY=1 should enforce clientOnly', async () => {
+  const uniqueSocketPath = path.join(os.tmpdir(), `smartipc-clientonly-env-${Date.now()}.sock`);
+  const prev = process.env.SMARTIPC_CLIENT_ONLY;
+  process.env.SMARTIPC_CLIENT_ONLY = '1';
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'clientonly-test-env',
+    socketPath: uniqueSocketPath,
+    clientId: 'co-client-2',
+    connectRetry: { enabled: false }
+  });
+
+  let failed = false;
+  try {
+    await client.connect();
+  } catch (err: any) {
+    failed = true;
+    expect(err.message).toContain('clientOnly prevents auto-start');
+  }
+  expect(failed).toBeTrue();
+  expect(fs.existsSync(uniqueSocketPath)).toBeFalse();
+
+  // restore env
+  if (prev === undefined) {
+    delete process.env.SMARTIPC_CLIENT_ONLY;
+  } else {
+    process.env.SMARTIPC_CLIENT_ONLY = prev;
+  }
+});
+
+// Cleanup
+tap.test('Cleanup test socket', async () => {
+  try {
+    fs.unlinkSync(testSocketPath);
+  } catch (e) {
+    // Ignore if doesn't exist
+  }
+});
+
+export default tap.start();

test/test.reliability.ts

@@ -0,0 +1,286 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartipc from '../ts/index.js';
+import * as path from 'path';
+import * as fs from 'fs';
+import * as os from 'os';
+
+const testSocketPath = path.join(os.tmpdir(), `test-ipc-reliability-${Date.now()}.sock`);
+
+tap.test('Server Readiness API', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true
+  });
+
+  let readyEventFired = false;
+  server.on('ready', () => {
+    readyEventFired = true;
+  });
+
+  // Start server with 'accepting' readiness mode
+  await server.start({ readyWhen: 'accepting' });
+  
+  // Check that ready event was fired
+  expect(readyEventFired).toBeTrue();
+  expect(server.getIsReady()).toBeTrue();
+
+  await server.stop();
+});
+
+tap.test('Automatic Socket Cleanup', async () => {
+  // Create a stale socket file
+  fs.writeFileSync(testSocketPath, '');
+  expect(fs.existsSync(testSocketPath)).toBeTrue();
+
+  const server = smartipc.SmartIpc.createServer({
+    id: 'test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    socketMode: 0o600
+  });
+
+  // Should clean up stale socket and start successfully
+  await server.start();
+  expect(server.getIsReady()).toBeTrue();
+  
+  await server.stop();
+});
+
+tap.test('Client Connection Retry', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'retry-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true
+  });
+
+  // Create client with retry configuration
+  const client = smartipc.SmartIpc.createClient({
+    id: 'retry-client',
+    socketPath: testSocketPath,
+    connectRetry: {
+      enabled: true,
+      initialDelay: 50,
+      maxDelay: 500,
+      maxAttempts: 10,
+      totalTimeout: 5000
+    },
+    registerTimeoutMs: 3000
+  });
+
+  // Start server first with accepting readiness mode
+  await server.start({ readyWhen: 'accepting' });
+  
+  // Give server a moment to be fully ready
+  await new Promise(resolve => setTimeout(resolve, 100));
+
+  // Client should connect successfully with retry enabled
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+tap.test('Graceful Heartbeat Handling', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'heartbeat-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    heartbeat: true,
+    heartbeatInterval: 100,
+    heartbeatTimeout: 500,
+    heartbeatInitialGracePeriodMs: 1000,
+    heartbeatThrowOnTimeout: false
+  });
+
+  // Add error handler to prevent unhandled error
+  server.on('error', (error) => {
+    // Ignore heartbeat errors in this test
+  });
+
+  await server.start({ readyWhen: 'accepting' });
+  
+  // Give server a moment to be fully ready
+  await new Promise(resolve => setTimeout(resolve, 100));
+
+  const client = smartipc.SmartIpc.createClient({
+    id: 'heartbeat-client',
+    socketPath: testSocketPath,
+    heartbeat: true,
+    heartbeatInterval: 100,
+    heartbeatTimeout: 500,
+    heartbeatInitialGracePeriodMs: 1000,
+    heartbeatThrowOnTimeout: false
+  });
+
+  let heartbeatTimeoutFired = false;
+  client.on('heartbeatTimeout', () => {
+    heartbeatTimeoutFired = true;
+  });
+  
+  // Add error handler to prevent unhandled error
+  client.on('error', (error) => {
+    // Ignore errors in this test
+  });
+
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  // Wait to ensure heartbeat is working
+  await new Promise(resolve => setTimeout(resolve, 300));
+  
+  // Heartbeat should not timeout during normal operation
+  expect(heartbeatTimeoutFired).toBeFalse();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+tap.test('Test Helper - waitForServer', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'wait-test-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true
+  });
+
+  // Start server after a delay
+  setTimeout(() => {
+    server.start();
+  }, 100);
+
+  // Wait for server should succeed
+  await smartipc.SmartIpc.waitForServer({
+    socketPath: testSocketPath,
+    timeoutMs: 3000
+  });
+
+  // Server should be ready
+  const client = smartipc.SmartIpc.createClient({
+    id: 'wait-test-client',
+    socketPath: testSocketPath
+  });
+  
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  await client.disconnect();
+  await server.stop();
+});
+
+tap.test('Race Condition - Immediate Connect After Server Start', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'race-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true
+  });
+
+  // Start server and immediately try to connect
+  const serverPromise = server.start({ readyWhen: 'accepting' });
+  
+  const client = smartipc.SmartIpc.createClient({
+    id: 'race-client',
+    socketPath: testSocketPath,
+    connectRetry: {
+      enabled: true,
+      maxAttempts: 20,
+      initialDelay: 10,
+      maxDelay: 100
+    },
+    registerTimeoutMs: 5000
+  });
+
+  // Wait for server to be ready
+  await serverPromise;
+  
+  // Client should be able to connect without race condition
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+
+  // Test request/response to ensure full functionality
+  server.onMessage('test', async (data) => {
+    return { echo: data };
+  });
+
+  const response = await client.request('test', { message: 'hello' });
+  expect(response.echo.message).toEqual('hello');
+
+  await client.disconnect();
+  await server.stop();
+});
+
+tap.test('Multiple Clients with Retry', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'multi-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
+    maxClients: 10
+  });
+
+  await server.start({ readyWhen: 'accepting' });
+
+  // Create multiple clients with retry
+  const clients = [];
+  for (let i = 0; i < 5; i++) {
+    const client = smartipc.SmartIpc.createClient({
+      id: `client-${i}`,
+      socketPath: testSocketPath,
+      connectRetry: {
+        enabled: true,
+        maxAttempts: 5
+      }
+    });
+    clients.push(client);
+  }
+
+  // Connect all clients concurrently
+  await Promise.all(clients.map(c => c.connect()));
+
+  // Verify all connected
+  for (const client of clients) {
+    expect(client.getIsConnected()).toBeTrue();
+  }
+
+  // Disconnect all
+  await Promise.all(clients.map(c => c.disconnect()));
+  await server.stop();
+});
+
+tap.test('Server Restart with Socket Cleanup', async () => {
+  const server = smartipc.SmartIpc.createServer({
+    id: 'restart-server',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true
+  });
+
+  // First start
+  await server.start();
+  expect(server.getIsReady()).toBeTrue();
+  await server.stop();
+
+  // Second start - should cleanup and work
+  await server.start();
+  expect(server.getIsReady()).toBeTrue();
+  
+  const client = smartipc.SmartIpc.createClient({
+    id: 'restart-client',
+    socketPath: testSocketPath
+  });
+  
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+  
+  await client.disconnect();
+  await server.stop();
+});
+
+// Clean up test socket file
+tap.test('Cleanup', async () => {
+  try {
+    fs.unlinkSync(testSocketPath);
+  } catch (e) {
+    // Ignore if doesn't exist
+  }
+});
+
+export default tap.start();

test/test.streaming.ts

@@ -0,0 +1,218 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as smartipc from '../ts/index.js';
+import * as smartdelay from '@push.rocks/smartdelay';
+import * as plugins from '../ts/smartipc.plugins.js';
+import * as fs from 'fs';
+import * as path from 'path';
+
+let server: smartipc.IpcServer;
+let client: smartipc.IpcClient;
+
+tap.test('setup TCP server and client (streaming)', async () => {
+  server = smartipc.SmartIpc.createServer({
+    id: 'stream-test-server',
+    host: '127.0.0.1',
+    port: 19876,
+    heartbeat: false
+  });
+  await server.start();
+
+  client = smartipc.SmartIpc.createClient({
+    id: 'stream-test-server',
+    host: '127.0.0.1',
+    port: 19876,
+    clientId: 'stream-client-1',
+    heartbeat: false
+  });
+  await client.connect();
+  expect(client.getIsConnected()).toBeTrue();
+});
+
+tap.test('client -> server streaming large payload', async () => {
+  // Create ~5MB buffer
+  const size = 5 * 1024 * 1024 + 123; // add some non-chunk-aligned bytes
+  const data = Buffer.alloc(size);
+  for (let i = 0; i < size; i++) data[i] = i % 251;
+
+  const received: Buffer[] = [];
+  const done = new Promise<void>((resolve, reject) => {
+    server.on('stream', (info: any, readable: plugins.stream.Readable) => {
+      // only handle our test stream
+      if (info?.meta?.direction === 'client-to-server') {
+        readable.on('data', chunk => received.push(Buffer.from(chunk)));
+        readable.on('end', resolve);
+        readable.on('error', reject);
+      }
+    });
+  });
+
+  // Send stream from client
+  const readable = plugins.stream.Readable.from(data);
+  await client.sendStream(readable, { meta: { direction: 'client-to-server' }, chunkSize: 64 * 1024 });
+
+  await done;
+  const result = Buffer.concat(received);
+  expect(result.length).toEqual(data.length);
+  expect(result.equals(data)).toBeTrue();
+});
+
+tap.test('server -> client streaming large payload', async () => {
+  const size = 6 * 1024 * 1024 + 7;
+  const data = Buffer.alloc(size);
+  for (let i = 0; i < size; i++) data[i] = (i * 7) % 255;
+
+  const received: Buffer[] = [];
+  const done = new Promise<void>((resolve, reject) => {
+    client.on('stream', (info: any, readable: plugins.stream.Readable) => {
+      if (info?.meta?.direction === 'server-to-client') {
+        readable.on('data', chunk => received.push(Buffer.from(chunk)));
+        readable.on('end', resolve);
+        readable.on('error', reject);
+      }
+    });
+  });
+
+  const readable = plugins.stream.Readable.from(data);
+  await server.sendStreamToClient('stream-client-1', readable, { meta: { direction: 'server-to-client' }, chunkSize: 64 * 1024 });
+
+  await done;
+  const result = Buffer.concat(received);
+  expect(result.length).toEqual(data.length);
+  expect(result.equals(data)).toBeTrue();
+});
+
+tap.test('client -> server file transfer to disk', async () => {
+  const baseTmp1 = path.join(process.cwd(), '.nogit', 'tmp');
+  fs.mkdirSync(baseTmp1, { recursive: true });
+  const tmpDir = fs.mkdtempSync(path.join(baseTmp1, 'tmp-'));
+  const srcPath = path.join(tmpDir, 'src.bin');
+  const dstPath = path.join(tmpDir, 'dst.bin');
+
+  // Prepare file ~1MB
+  const size = 1024 * 1024 + 333;
+  const buf = Buffer.alloc(size);
+  for (let i = 0; i < size; i++) buf[i] = (i * 11) % 255;
+  fs.writeFileSync(srcPath, buf);
+
+  const done = new Promise<void>((resolve, reject) => {
+    server.on('stream', async (info: any, readable: plugins.stream.Readable) => {
+      if (info?.meta?.type === 'file' && info?.meta?.basename === 'src.bin') {
+        try {
+          await smartipc.pipeStreamToFile(readable, dstPath);
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      }
+    });
+  });
+
+  await client.sendFile(srcPath);
+  await done;
+  const out = fs.readFileSync(dstPath);
+  expect(out.equals(buf)).toBeTrue();
+});
+
+tap.test('server -> client file transfer to disk', async () => {
+  const baseTmp2 = path.join(process.cwd(), '.nogit', 'tmp');
+  fs.mkdirSync(baseTmp2, { recursive: true });
+  const tmpDir = fs.mkdtempSync(path.join(baseTmp2, 'tmp-'));
+  const srcPath = path.join(tmpDir, 'serverfile.bin');
+  const dstPath = path.join(tmpDir, 'clientfile.bin');
+
+  const size = 512 * 1024 + 77;
+  const buf = Buffer.alloc(size);
+  for (let i = 0; i < size; i++) buf[i] = (i * 17) % 251;
+  fs.writeFileSync(srcPath, buf);
+
+  const done = new Promise<void>((resolve, reject) => {
+    client.on('stream', async (info: any, readable: plugins.stream.Readable) => {
+      if (info?.meta?.type === 'file' && info?.meta?.basename === 'serverfile.bin') {
+        try {
+          await smartipc.pipeStreamToFile(readable, dstPath);
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      }
+    });
+  });
+
+  await server.sendFileToClient('stream-client-1', srcPath);
+  await done;
+  const out = fs.readFileSync(dstPath);
+  expect(out.equals(buf)).toBeTrue();
+});
+
+tap.test('receiver cancels an incoming stream', async () => {
+  // Create a slow readable that emits many chunks
+  const bigChunk = Buffer.alloc(128 * 1024, 1);
+  let pushed = 0;
+  const readable = new plugins.stream.Readable({
+    read() {
+      setTimeout(() => {
+        if (pushed > 200) {
+          this.push(null);
+        } else {
+          this.push(bigChunk);
+          pushed++;
+        }
+      }, 5);
+    }
+  });
+
+  let cancelled = false;
+  const cancelPromise = new Promise<void>((resolve) => {
+    server.on('stream', (info: any, r: plugins.stream.Readable) => {
+      if (info?.meta?.direction === 'client-to-server-cancel') {
+        // cancel after first chunk
+        r.once('data', async () => {
+          cancelled = true;
+          // send cancel back to sender
+          await (server as any).primaryChannel.cancelIncomingStream(info.streamId, { clientId: info.clientId });
+          resolve();
+        });
+        r.on('error', () => { /* ignore cancellation error */ });
+        // drain to trigger data
+        r.resume();
+      }
+    });
+  });
+
+  const sendPromise = client
+    .sendStream(readable, { meta: { direction: 'client-to-server-cancel' } })
+    .catch(() => { /* expected due to cancel */ });
+  await cancelPromise;
+  expect(cancelled).toBeTrue();
+  await sendPromise;
+});
+
+tap.test('enforce maxConcurrentStreams option', async () => {
+  // Setup separate low-limit server/client
+  const srv = smartipc.SmartIpc.createServer({ id: 'limit-srv', host: '127.0.0.1', port: 19999, heartbeat: false, maxConcurrentStreams: 1 });
+  await srv.start();
+  const cli = smartipc.SmartIpc.createClient({ id: 'limit-srv', host: '127.0.0.1', port: 19999, clientId: 'limit-client', heartbeat: false, maxConcurrentStreams: 1 });
+  await cli.connect();
+
+  const r1 = plugins.stream.Readable.from(Buffer.alloc(256 * 1024));
+  const r2 = plugins.stream.Readable.from(Buffer.alloc(256 * 1024));
+  const p1 = cli.sendStream(r1, { meta: { n: 1 } });
+  let threw = false;
+  try {
+    await cli.sendStream(r2, { meta: { n: 2 } });
+  } catch (e) {
+    threw = true;
+  }
+  expect(threw).toBeTrue();
+  await p1;
+  await cli.disconnect();
+  await srv.stop();
+});
+
+tap.test('cleanup streaming test', async () => {
+  await client.disconnect();
+  await server.stop();
+  await smartdelay.delayFor(50);
+});
+
+export default tap.start();

test/test.ts

@@ -2,6 +2,10 @@ import { expect, tap } from '@git.zone/tstest/tapbundle';
 import * as smartipc from '../ts/index.js';
 import * as smartdelay from '@push.rocks/smartdelay';
 import * as smartpromise from '@push.rocks/smartpromise';
+import * as path from 'path';
+import * as os from 'os';
+
+const testSocketPath = path.join(os.tmpdir(), `test-smartipc-${Date.now()}.sock`);
 
 let server: smartipc.IpcServer;
 let client1: smartipc.IpcClient;
@@ -11,12 +15,13 @@ let client2: smartipc.IpcClient;
 tap.test('should create and start an IPC server', async () => {
   server = smartipc.SmartIpc.createServer({
     id: 'test-server',
-    socketPath: '/tmp/test-smartipc.sock',
+    socketPath: testSocketPath,
+    autoCleanupSocketFile: true,
     heartbeat: true,
     heartbeatInterval: 2000
   });
 
-  await server.start();
+  await server.start({ readyWhen: 'accepting' });
   expect(server.getStats().isRunning).toBeTrue();
 });
 
@@ -24,11 +29,12 @@ tap.test('should create and start an IPC server', async () => {
 tap.test('should create and connect a client', async () => {
   client1 = smartipc.SmartIpc.createClient({
     id: 'test-server',
-    socketPath: '/tmp/test-smartipc.sock',
+    socketPath: testSocketPath,
     clientId: 'client-1',
     metadata: { name: 'Test Client 1' },
     autoReconnect: true,
-    heartbeat: true
+    heartbeat: true,
+    clientOnly: true
   });
 
   await client1.connect();
@@ -76,9 +82,10 @@ tap.test('should handle request/response pattern', async () => {
 tap.test('should handle multiple clients', async () => {
   client2 = smartipc.SmartIpc.createClient({
     id: 'test-server',
-    socketPath: '/tmp/test-smartipc.sock',
+    socketPath: testSocketPath,
     clientId: 'client-2',
-    metadata: { name: 'Test Client 2' }
+    metadata: { name: 'Test Client 2' },
+    clientOnly: true
   });
 
   await client2.connect();
@@ -154,17 +161,6 @@ tap.test('should handle pub/sub pattern', async () => {
     messageReceived.resolve();
   });
 
-  // Server handles the subscription
-  server.onMessage('__subscribe__', async (payload, clientId) => {
-    expect(payload.topic).toEqual('news');
-  });
-
-  // Server handles publishing
-  server.onMessage('__publish__', async (payload, clientId) => {
-    // Broadcast to all subscribers of the topic
-    await server.broadcast(`topic:${payload.topic}`, payload.payload);
-  });
-
   // Client 2 publishes to the topic
   await client2.publish('news', { headline: 'Breaking news!' });
 

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartipc',
-  version: '2.0.1',
+  version: '2.3.0',
   description: 'A library for node inter process communication, providing an easy-to-use API for IPC.'
 }

ts/classes.ipcchannel.ts

@@ -22,6 +22,12 @@ export interface IIpcChannelOptions extends IIpcTransportOptions {
   heartbeatInterval?: number;
   /** Heartbeat timeout in ms */
   heartbeatTimeout?: number;
+  /** Initial grace period before heartbeat timeout in ms */
+  heartbeatInitialGracePeriodMs?: number;
+  /** Throw on heartbeat timeout (default: true, set false to emit event instead) */
+  heartbeatThrowOnTimeout?: boolean;
+  /** Maximum concurrent streams (incoming/outgoing) */
+  maxConcurrentStreams?: number;
 }
 
 /**
@@ -45,9 +51,17 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
   private reconnectTimer?: NodeJS.Timeout;
   private heartbeatTimer?: NodeJS.Timeout;
   private heartbeatCheckTimer?: NodeJS.Timeout;
+  private heartbeatGraceTimer?: NodeJS.Timeout;
   private lastHeartbeat: number = Date.now();
+  private connectionStartTime: number = Date.now();
   private isReconnecting = false;
   private isClosing = false;
+  // Streaming state
+  private incomingStreams = new Map<string, plugins.stream.PassThrough>();
+  private incomingStreamMeta = new Map<string, Record<string, any>>();
+  private outgoingStreams = new Map<string, { cancelled: boolean; abort?: () => void }>();
+  private activeIncomingStreams = 0;
+  private activeOutgoingStreams = 0;
   
   // Metrics
   private metrics = {
@@ -73,9 +87,22 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
       heartbeat: true,
       heartbeatInterval: 5000,
       heartbeatTimeout: 10000,
+      maxConcurrentStreams: 32,
       ...options
     };
 
+    // Normalize heartbeatThrowOnTimeout to boolean (defensive for JS consumers)
+    const throwOnTimeout = (this.options as any).heartbeatThrowOnTimeout;
+    if (throwOnTimeout !== undefined) {
+      if (throwOnTimeout === 'false') {
+        this.options.heartbeatThrowOnTimeout = false;
+      } else if (throwOnTimeout === 'true') {
+        this.options.heartbeatThrowOnTimeout = true;
+      } else if (typeof throwOnTimeout !== 'boolean') {
+        this.options.heartbeatThrowOnTimeout = Boolean(throwOnTimeout);
+      }
+    }
+
     this.transport = createTransport(this.options);
     this.setupTransportHandlers();
   }
@@ -110,6 +137,13 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
       this.handleMessage(message);
     });
 
+    // Forward per-client disconnects from transports that support multi-client servers
+    // We re-emit a 'clientDisconnected' event with the clientId if known so higher layers can act.
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    (this.transport as any).on?.('clientDisconnected', (_socket: any, clientId?: string) => {
+      this.emit('clientDisconnected', clientId);
+    });
+
     this.transport.on('drain', () => {
       this.emit('drain');
     });
@@ -203,6 +237,7 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
 
     this.stopHeartbeat();
     this.lastHeartbeat = Date.now();
+    this.connectionStartTime = Date.now();
 
     // Send heartbeat messages
     this.heartbeatTimer = setInterval(() => {
@@ -211,14 +246,43 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
       });
     }, this.options.heartbeatInterval!);
 
+    // Delay starting the check until after the grace period
+    const gracePeriod = this.options.heartbeatInitialGracePeriodMs || 0;
+    
+    if (gracePeriod > 0) {
+      // Use a timer to delay the first check
+      this.heartbeatGraceTimer = setTimeout(() => {
+        this.startHeartbeatCheck();
+      }, gracePeriod);
+    } else {
+      // No grace period, start checking immediately
+      this.startHeartbeatCheck();
+    }
+  }
+
+  /**
+   * Start heartbeat timeout checking (separated for grace period handling)
+   */
+  private startHeartbeatCheck(): void {
     // Check for heartbeat timeout
     this.heartbeatCheckTimer = setInterval(() => {
       const timeSinceLastHeartbeat = Date.now() - this.lastHeartbeat;
+      
       if (timeSinceLastHeartbeat > this.options.heartbeatTimeout!) {
-        this.emit('error', new Error('Heartbeat timeout'));
+        const error = new Error('Heartbeat timeout');
+        
+        if (this.options.heartbeatThrowOnTimeout !== false) {
+          // Default behavior: emit error which may cause disconnect
+          this.emit('error', error);
           this.transport.disconnect().catch(() => {});
+        } else {
+          // Emit heartbeatTimeout event instead of error
+          this.emit('heartbeatTimeout', error);
+          // Clear timers to avoid repeated events
+          this.stopHeartbeat();
         }
-    }, this.options.heartbeatTimeout! / 2);
+      }
+    }, Math.max(1000, Math.floor(this.options.heartbeatTimeout! / 2)));
   }
 
   /**
@@ -234,6 +298,11 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
       clearInterval(this.heartbeatCheckTimer);
       this.heartbeatCheckTimer = undefined;
     }
+
+    if (this.heartbeatGraceTimer) {
+      clearTimeout(this.heartbeatGraceTimer);
+      this.heartbeatGraceTimer = undefined;
+    }
   }
 
   /**
@@ -265,6 +334,105 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
       return;
     }
 
+    // Handle streaming control messages
+    if (message.type === '__stream_init__') {
+      const streamId = (message.payload as any)?.streamId as string;
+      const meta = (message.payload as any)?.meta as Record<string, any> | undefined;
+      if (typeof streamId === 'string' && streamId.length) {
+        // Enforce max concurrent incoming streams
+        if (this.activeIncomingStreams >= (this.options.maxConcurrentStreams || Infinity)) {
+          const response: IIpcMessageEnvelope = {
+            id: plugins.crypto.randomUUID(),
+            type: '__stream_error__',
+            timestamp: Date.now(),
+            payload: { streamId, error: 'Max concurrent streams exceeded' },
+            headers: message.headers?.clientId ? { clientId: message.headers.clientId } : undefined
+          };
+          this.transport.send(response).catch(() => {});
+          return;
+        }
+        const pass = new plugins.stream.PassThrough();
+        this.incomingStreams.set(streamId, pass);
+        if (meta) this.incomingStreamMeta.set(streamId, meta);
+        this.activeIncomingStreams++;
+        // Emit a high-level stream event
+        const headersClientId = message.headers?.clientId;
+        const eventPayload = {
+          streamId,
+          meta: meta || {},
+          headers: message.headers || {},
+          clientId: headersClientId,
+        };
+        // Emit as ('stream', info, readable)
+        this.emit('stream', eventPayload, pass);
+      }
+      return;
+    }
+
+    if (message.type === '__stream_chunk__') {
+      const streamId = (message.payload as any)?.streamId as string;
+      const chunkB64 = (message.payload as any)?.chunk as string;
+      const pass = this.incomingStreams.get(streamId);
+      if (pass && typeof chunkB64 === 'string') {
+        try {
+          const chunk = Buffer.from(chunkB64, 'base64');
+          pass.write(chunk);
+        } catch (e) {
+          // If decode fails, destroy stream
+          pass.destroy(e as Error);
+          this.incomingStreams.delete(streamId);
+          this.incomingStreamMeta.delete(streamId);
+        }
+      }
+      return;
+    }
+
+    if (message.type === '__stream_end__') {
+      const streamId = (message.payload as any)?.streamId as string;
+      const pass = this.incomingStreams.get(streamId);
+      if (pass) {
+        pass.end();
+        this.incomingStreams.delete(streamId);
+        this.incomingStreamMeta.delete(streamId);
+        this.activeIncomingStreams = Math.max(0, this.activeIncomingStreams - 1);
+      }
+      return;
+    }
+
+    if (message.type === '__stream_error__') {
+      const streamId = (message.payload as any)?.streamId as string;
+      const errMsg = (message.payload as any)?.error as string;
+      const pass = this.incomingStreams.get(streamId);
+      if (pass) {
+        pass.destroy(new Error(errMsg || 'stream error'));
+        this.incomingStreams.delete(streamId);
+        this.incomingStreamMeta.delete(streamId);
+        this.activeIncomingStreams = Math.max(0, this.activeIncomingStreams - 1);
+      }
+      return;
+    }
+
+    if (message.type === '__stream_cancel__') {
+      const streamId = (message.payload as any)?.streamId as string;
+      // Cancel outgoing stream with same id if present
+      const ctrl = this.outgoingStreams.get(streamId);
+      if (ctrl) {
+        ctrl.cancelled = true;
+        try { ctrl.abort?.(); } catch {}
+        this.outgoingStreams.delete(streamId);
+        this.activeOutgoingStreams = Math.max(0, this.activeOutgoingStreams - 1);
+      }
+      // Also cancel any incoming stream if tracked
+      const pass = this.incomingStreams.get(streamId);
+      if (pass) {
+        try { pass.destroy(new Error('stream cancelled')); } catch {}
+        this.incomingStreams.delete(streamId);
+        this.incomingStreamMeta.delete(streamId);
+        this.activeIncomingStreams = Math.max(0, this.activeIncomingStreams - 1);
+      }
+      return;
+    }
+
     // Handle request/response
     if (message.correlationId && this.pendingRequests.has(message.correlationId)) {
       const pending = this.pendingRequests.get(message.correlationId)!;
@@ -408,7 +576,7 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
    * Register a message handler
    */
   public on(event: string, handler: (payload: any) => any | Promise<any>): this {
-    if (event === 'message' || event === 'connect' || event === 'disconnect' || event === 'error' || event === 'reconnecting' || event === 'drain') {
+    if (event === 'message' || event === 'connect' || event === 'disconnect' || event === 'error' || event === 'reconnecting' || event === 'drain' || event === 'heartbeatTimeout' || event === 'clientDisconnected' || event === 'stream') {
       // Special handling for channel events
       super.on(event, handler);
     } else {
@@ -470,3 +638,129 @@ export class IpcChannel<TRequest = any, TResponse = any> extends plugins.EventEm
     };
   }
 }
+
+/**
+ * Streaming helpers
+ */
+export interface IStreamSendOptions {
+  headers?: Record<string, any>;
+  chunkSize?: number; // bytes, default 64k
+  streamId?: string;
+  meta?: Record<string, any>;
+}
+
+export type ReadableLike = NodeJS.ReadableStream | plugins.stream.Readable;
+
+// Extend IpcChannel with a sendStream method
+export interface IpcChannel<TRequest, TResponse> {
+  sendStream(readable: ReadableLike, options?: IStreamSendOptions): Promise<void>;
+  cancelOutgoingStream(streamId: string, headers?: Record<string, any>): Promise<void>;
+  cancelIncomingStream(streamId: string, headers?: Record<string, any>): Promise<void>;
+}
+
+IpcChannel.prototype.sendStream = async function(this: IpcChannel, readable: ReadableLike, options?: IStreamSendOptions): Promise<void> {
+  const streamId = options?.streamId || (plugins.crypto.randomUUID ? plugins.crypto.randomUUID() : `${Date.now()}-${Math.random()}`);
+  const headers = options?.headers || {};
+  const chunkSize = Math.max(1024, Math.min(options?.chunkSize || 64 * 1024, (this as any).options.maxMessageSize || 8 * 1024 * 1024));
+  const self: any = this;
+
+  // Enforce max concurrent outgoing streams (reserve a slot synchronously)
+  if (self.activeOutgoingStreams >= (self.options.maxConcurrentStreams || Infinity)) {
+    throw new Error('Max concurrent streams exceeded');
+  }
+  self.activeOutgoingStreams++;
+  self.outgoingStreams.set(streamId, {
+    cancelled: false,
+    abort: () => {
+      try { (readable as any).destroy?.(new Error('stream cancelled')); } catch {}
+    }
+  });
+  try {
+    // Send init after reserving slot
+    await (this as any).sendMessage('__stream_init__', { streamId, meta: options?.meta || {} }, headers);
+  } catch (e) {
+    self.outgoingStreams.delete(streamId);
+    self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+    throw e;
+  }
+
+  const readChunkAndSend = async (buf: Buffer) => {
+    // Slice into chunkSize frames if needed
+    for (let offset = 0; offset < buf.length; offset += chunkSize) {
+      const ctrl = self.outgoingStreams.get(streamId);
+      if (ctrl?.cancelled) {
+        return;
+      }
+      const slice = buf.subarray(offset, Math.min(offset + chunkSize, buf.length));
+      const chunkB64 = slice.toString('base64');
+      await (this as any).sendMessage('__stream_chunk__', { streamId, chunk: chunkB64 }, headers);
+    }
+  };
+
+  await new Promise<void>((resolve, reject) => {
+    let sending = Promise.resolve();
+    readable.on('data', (chunk: any) => {
+      const buf = Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk);
+      // Ensure sequential sending to avoid write races
+      sending = sending.then(() => readChunkAndSend(buf));
+      sending.catch(reject);
+    });
+    readable.on('end', async () => {
+      try {
+        await sending;
+        await (this as any).sendMessage('__stream_end__', { streamId }, headers);
+        self.outgoingStreams.delete(streamId);
+        self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+        resolve();
+      } catch (e) {
+        self.outgoingStreams.delete(streamId);
+        self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+        reject(e);
+      }
+    });
+    readable.on('error', async (err: Error) => {
+      try {
+        await sending.catch(() => {});
+        await (this as any).sendMessage('__stream_error__', { streamId, error: err.message }, headers);
+      } finally {
+        self.outgoingStreams.delete(streamId);
+        self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+        reject(err);
+      }
+    });
+    // In case the stream is already ended
+    const r = readable as any;
+    if (r.readableEnded) {
+      (async () => {
+        await (this as any).sendMessage('__stream_end__', { streamId }, headers);
+        self.outgoingStreams.delete(streamId);
+        self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+        resolve();
+      })().catch(reject);
+    }
+  });
+};
+
+IpcChannel.prototype.cancelOutgoingStream = async function(this: IpcChannel, streamId: string, headers?: Record<string, any>): Promise<void> {
+  const self: any = this;
+  const ctrl = self.outgoingStreams.get(streamId);
+  if (ctrl) {
+    ctrl.cancelled = true;
+    try { ctrl.abort?.(); } catch {}
+    self.outgoingStreams.delete(streamId);
+    self.activeOutgoingStreams = Math.max(0, self.activeOutgoingStreams - 1);
+  }
+  await (this as any).sendMessage('__stream_cancel__', { streamId }, headers || {});
+};
+
+IpcChannel.prototype.cancelIncomingStream = async function(this: IpcChannel, streamId: string, headers?: Record<string, any>): Promise<void> {
+  const self: any = this;
+  const pass = self.incomingStreams.get(streamId);
+  if (pass) {
+    try { pass.destroy(new Error('stream cancelled')); } catch {}
+    self.incomingStreams.delete(streamId);
+    self.incomingStreamMeta.delete(streamId);
+    self.activeIncomingStreams = Math.max(0, self.activeIncomingStreams - 1);
+  }
+  await (this as any).sendMessage('__stream_cancel__', { streamId }, headers || {});
+};

ts/classes.ipcclient.ts

@@ -5,11 +5,35 @@ import type { IIpcChannelOptions } from './classes.ipcchannel.js';
 /**
  * Options for IPC Client
  */
+export interface IConnectRetryConfig {
+  /** Enable connection retry */
+  enabled: boolean;
+  /** Initial delay before first retry in ms */
+  initialDelay?: number;
+  /** Maximum delay between retries in ms */
+  maxDelay?: number;
+  /** Maximum number of attempts */
+  maxAttempts?: number;
+  /** Total timeout for all retry attempts in ms */
+  totalTimeout?: number;
+}
+
+export interface IClientConnectOptions {
+  /** Wait for server to be ready before attempting connection */
+  waitForReady?: boolean;
+  /** Timeout for waiting for server readiness in ms */
+  waitTimeout?: number;
+}
+
 export interface IIpcClientOptions extends IIpcChannelOptions {
   /** Client identifier */
   clientId?: string;
   /** Client metadata */
   metadata?: Record<string, any>;
+  /** Connection retry configuration */
+  connectRetry?: IConnectRetryConfig;
+  /** Registration timeout in ms (default: 5000) */
+  registerTimeoutMs?: number;
 }
 
 /**
@@ -21,6 +45,7 @@ export class IpcClient extends plugins.EventEmitter {
   private messageHandlers = new Map<string, (payload: any) => any | Promise<any>>();
   private isConnected = false;
   private clientId: string;
+  private didRegisterOnce = false;
 
   constructor(options: IIpcClientOptions) {
     super();
@@ -35,15 +60,103 @@ export class IpcClient extends plugins.EventEmitter {
   /**
    * Connect to the server
    */
-  public async connect(): Promise<void> {
+  public async connect(connectOptions: IClientConnectOptions = {}): Promise<void> {
     if (this.isConnected) {
       return;
     }
 
+    // Helper function to attempt registration
+    const attemptRegistration = async (): Promise<void> => {
+      await this.attemptRegistrationInternal();
+    };
+
+    // Helper function to attempt connection with retry
+    const attemptConnection = async (): Promise<void> => {
+      const retryConfig = this.options.connectRetry;
+      const maxAttempts = retryConfig?.maxAttempts || 1;
+      const initialDelay = retryConfig?.initialDelay || 100;
+      const maxDelay = retryConfig?.maxDelay || 1500;
+      const totalTimeout = retryConfig?.totalTimeout || 15000;
+      
+      const startTime = Date.now();
+      let lastError: Error | undefined;
+      let delay = initialDelay;
+
+      for (let attempt = 1; attempt <= maxAttempts; attempt++) {
+        // Check total timeout
+        if (totalTimeout && Date.now() - startTime > totalTimeout) {
+          throw new Error(`Connection timeout after ${totalTimeout}ms: ${lastError?.message || 'Unknown error'}`);
+        }
+
+        try {
           // Connect the channel
           await this.channel.connect();
           
-    // Register with the server
+          // Attempt registration
+          await attemptRegistration();
+          return; // Success!
+        } catch (error) {
+          lastError = error as Error;
+          
+          // Disconnect channel for retry
+          await this.channel.disconnect().catch(() => {});
+          
+          // If this isn't the last attempt and retry is enabled, wait before retrying
+          if (attempt < maxAttempts && retryConfig?.enabled) {
+            // Check if we have time for another attempt
+            if (totalTimeout && Date.now() - startTime + delay > totalTimeout) {
+              break; // Will timeout, don't wait
+            }
+            
+            await new Promise(resolve => setTimeout(resolve, delay));
+            // Exponential backoff with max limit
+            delay = Math.min(delay * 2, maxDelay);
+          }
+        }
+      }
+
+      // All attempts failed
+      throw lastError || new Error('Failed to connect to server');
+    };
+
+    // If waitForReady is specified, wait for server socket to exist first
+    if (connectOptions.waitForReady) {
+      const waitTimeout = connectOptions.waitTimeout || 10000;
+      // For Unix domain sockets / named pipes: wait explicitly using helper that probes with clientOnly
+      if (this.options.socketPath) {
+        const { SmartIpc } = await import('./index.js');
+        await (SmartIpc as any).waitForServer({ socketPath: this.options.socketPath, timeoutMs: waitTimeout });
+        await attemptConnection();
+        return;
+      }
+      // Fallback (e.g., TCP): retry-connect loop
+      const startTime = Date.now();
+      while (Date.now() - startTime < waitTimeout) {
+        try {
+          await attemptConnection();
+          return; // Success!
+        } catch (error) {
+          if ((error as any).message?.includes('ECONNREFUSED')) {
+            await new Promise(resolve => setTimeout(resolve, 100));
+            continue;
+          }
+          throw error;
+        }
+      }
+      throw new Error(`Server not ready after ${waitTimeout}ms`);
+    } else {
+      // Normal connection attempt
+      await attemptConnection();
+    }
+  }
+
+  /**
+   * Attempt to register this client over the current channel connection.
+   * Sets connection flags and emits 'connect' on success.
+   */
+  private async attemptRegistrationInternal(): Promise<void> {
+    const registerTimeoutMs = this.options.registerTimeoutMs || 5000;
+
     try {
       const response = await this.channel.request<any, any>(
         '__register__',
@@ -51,7 +164,10 @@ export class IpcClient extends plugins.EventEmitter {
           clientId: this.clientId,
           metadata: this.options.metadata
         },
-        { timeout: 5000 }
+        {
+          timeout: registerTimeoutMs,
+          headers: { clientId: this.clientId }
+        }
       );
 
       if (!response.success) {
@@ -59,9 +175,9 @@ export class IpcClient extends plugins.EventEmitter {
       }
 
       this.isConnected = true;
+      this.didRegisterOnce = true;
       this.emit('connect');
-    } catch (error) {
+    } catch (error: any) {
-      await this.channel.disconnect();
       throw new Error(`Failed to register with server: ${error.message}`);
     }
   }
@@ -84,8 +200,16 @@ export class IpcClient extends plugins.EventEmitter {
    */
   private setupChannelHandlers(): void {
     // Forward channel events
-    this.channel.on('connect', () => {
+    this.channel.on('connect', async () => {
-      // Don't emit connect here, wait for successful registration
+      // On reconnects, re-register automatically when we had connected before
+      if (this.didRegisterOnce && !this.isConnected) {
+        try {
+          await this.attemptRegistrationInternal();
+        } catch (error) {
+          this.emit('error', error);
+        }
+      }
+      // For initial connect(), registration is handled explicitly there
     });
 
     this.channel.on('disconnect', (reason) => {
@@ -93,14 +217,31 @@ export class IpcClient extends plugins.EventEmitter {
       this.emit('disconnect', reason);
     });
 
-    this.channel.on('error', (error) => {
+    this.channel.on('error', (error: any) => {
+      // If heartbeat timeout and configured not to throw, convert to heartbeatTimeout event
+      if (error && error.message === 'Heartbeat timeout' && this.options.heartbeatThrowOnTimeout === false) {
+        this.emit('heartbeatTimeout', error);
+        return;
+      }
       this.emit('error', error);
     });
 
+    this.channel.on('heartbeatTimeout', (error) => {
+      // Forward heartbeatTimeout event (when heartbeatThrowOnTimeout is false)
+      this.emit('heartbeatTimeout', error);
+    });
+
     this.channel.on('reconnecting', (info) => {
       this.emit('reconnecting', info);
     });
 
+    // Forward streaming events
+    // Emitted as ('stream', info, readable)
+    // info contains { streamId, meta, headers, clientId }
+    this.channel.on('stream', (info: any, readable: plugins.stream.Readable) => {
+      this.emit('stream', info, readable);
+    });
+
     // Handle messages
     this.channel.on('message', (message) => {
       // Check if we have a handler for this message type
@@ -229,4 +370,40 @@ export class IpcClient extends plugins.EventEmitter {
   public getStats(): any {
     return this.channel.getStats();
   }
+
+  /**
+   * Send a Node.js readable stream to the server
+   */
+  public async sendStream(readable: plugins.stream.Readable | NodeJS.ReadableStream, options?: { headers?: Record<string, any>; chunkSize?: number; streamId?: string; meta?: Record<string, any> }): Promise<void> {
+    const headers = { ...(options?.headers || {}), clientId: this.clientId };
+    await (this as any).channel.sendStream(readable as any, { ...options, headers });
+  }
+
+  /**
+   * Send a file to the server via streaming
+   */
+  public async sendFile(filePath: string, options?: { headers?: Record<string, any>; chunkSize?: number; streamId?: string; meta?: Record<string, any> }): Promise<void> {
+    const fs = plugins.fs;
+    const path = plugins.path;
+    const stat = fs.statSync(filePath);
+    const meta = {
+      ...(options?.meta || {}),
+      type: 'file',
+      basename: path.basename(filePath),
+      size: stat.size,
+      mtimeMs: stat.mtimeMs
+    };
+    const rs = fs.createReadStream(filePath);
+    await this.sendStream(rs, { ...options, meta });
+  }
+
+  /** Cancel an outgoing stream by id */
+  public async cancelOutgoingStream(streamId: string): Promise<void> {
+    await (this as any).channel.cancelOutgoingStream(streamId, { clientId: this.clientId });
+  }
+
+  /** Cancel an incoming stream by id */
+  public async cancelIncomingStream(streamId: string): Promise<void> {
+    await (this as any).channel.cancelIncomingStream(streamId, { clientId: this.clientId });
+  }
 }

ts/classes.ipcserver.ts

@@ -5,11 +5,20 @@ import type { IIpcChannelOptions } from './classes.ipcchannel.js';
 /**
  * Options for IPC Server
  */
+export interface IServerStartOptions {
+  /** When to consider server ready (default: 'socket-bound') */
+  readyWhen?: 'socket-bound' | 'accepting';
+}
+
 export interface IIpcServerOptions extends Omit<IIpcChannelOptions, 'autoReconnect' | 'reconnectDelay' | 'maxReconnectDelay' | 'reconnectMultiplier' | 'maxReconnectAttempts'> {
   /** Maximum number of client connections */
   maxClients?: number;
   /** Client idle timeout in ms */
   clientIdleTimeout?: number;
+  /** Automatically cleanup stale socket file on start (default: false) */
+  autoCleanupSocketFile?: boolean;
+  /** Socket file permissions mode (e.g. 0o600) */
+  socketMode?: number;
 }
 
 /**
@@ -32,6 +41,7 @@ export class IpcServer extends plugins.EventEmitter {
   private messageHandlers = new Map<string, (payload: any, clientId: string) => any | Promise<any>>();
   private primaryChannel?: IpcChannel;
   private isRunning = false;
+  private isReady = false;
   private clientIdleCheckTimer?: NodeJS.Timeout;
   
   // Pub/sub tracking
@@ -50,7 +60,7 @@ export class IpcServer extends plugins.EventEmitter {
   /**
    * Start the server
    */
-  public async start(): Promise<void> {
+  public async start(options: IServerStartOptions = {}): Promise<void> {
     if (this.isRunning) {
       return;
     }
@@ -190,12 +200,46 @@ export class IpcServer extends plugins.EventEmitter {
       this.emit('error', error, 'server');
     });
 
+    // Forward streaming events to server level
+    this.primaryChannel.on('stream', (info: any, readable: plugins.stream.Readable) => {
+      // Emit ('stream', info, readable)
+      this.emit('stream', info, readable);
+    });
+
+    this.primaryChannel.on('heartbeatTimeout', (error) => {
+      // Forward heartbeatTimeout event (when heartbeatThrowOnTimeout is false)
+      this.emit('heartbeatTimeout', error, 'server');
+    });
+
     // Connect the primary channel (will start as server)
     await this.primaryChannel.connect();
     
     this.isRunning = true;
     this.startClientIdleCheck();
     this.emit('start');
+
+    // Track individual client disconnects forwarded by the channel/transport
+    this.primaryChannel.on('clientDisconnected', (clientId?: string) => {
+      if (!clientId) return;
+      // Clean up any topic subscriptions and client map entry
+      this.cleanupClientSubscriptions(clientId);
+      if (this.clients.has(clientId)) {
+        this.clients.delete(clientId);
+        this.emit('clientDisconnect', clientId);
+      }
+    });
+    
+    // Handle readiness based on options
+    if (options.readyWhen === 'accepting') {
+      // Wait a bit to ensure handlers are fully set up
+      await new Promise(resolve => setTimeout(resolve, 10));
+      this.isReady = true;
+      this.emit('ready');
+    } else {
+      // Default: ready when socket is bound
+      this.isReady = true;
+      this.emit('ready');
+    }
   }
 
   /**
@@ -317,6 +361,19 @@ export class IpcServer extends plugins.EventEmitter {
       }
       this.emit('error', error, actualClientId);
     });
+
+    channel.on('heartbeatTimeout', (error) => {
+      // Find the actual client ID for this channel
+      let actualClientId = clientId;
+      for (const [id, client] of this.clients) {
+        if (client.channel === channel) {
+          actualClientId = id;
+          break;
+        }
+      }
+      // Forward heartbeatTimeout event (when heartbeatThrowOnTimeout is false)
+      this.emit('heartbeatTimeout', error, actualClientId);
+    });
   }
 
   /**
@@ -335,7 +392,60 @@ export class IpcServer extends plugins.EventEmitter {
       throw new Error(`Client ${clientId} not found`);
     }
 
-    await client.channel.sendMessage(type, payload, headers);
+    // Ensure the target clientId is part of the headers so the transport
+    // can route the message to the correct socket instead of broadcasting.
+    const routedHeaders: Record<string, any> | undefined = {
+      ...(headers || {}),
+      clientId,
+    };
+
+    await client.channel.sendMessage(type, payload, routedHeaders);
+  }
+
+  /**
+   * Send a Node.js readable stream to a specific client
+   */
+  public async sendStreamToClient(clientId: string, readable: plugins.stream.Readable | NodeJS.ReadableStream, options?: { headers?: Record<string, any>; chunkSize?: number; streamId?: string; meta?: Record<string, any> }): Promise<void> {
+    const client = this.clients.get(clientId);
+    if (!client) {
+      throw new Error(`Client ${clientId} not found`);
+    }
+    const headers = { ...(options?.headers || {}), clientId };
+    await (client.channel as any).sendStream(readable as any, { ...options, headers });
+  }
+
+  /**
+   * Send a file to a specific client via streaming
+   */
+  public async sendFileToClient(clientId: string, filePath: string, options?: { headers?: Record<string, any>; chunkSize?: number; streamId?: string; meta?: Record<string, any> }): Promise<void> {
+    const client = this.clients.get(clientId);
+    if (!client) {
+      throw new Error(`Client ${clientId} not found`);
+    }
+    const fs = plugins.fs;
+    const path = plugins.path;
+    const stat = fs.statSync(filePath);
+    const meta = {
+      ...(options?.meta || {}),
+      type: 'file',
+      basename: path.basename(filePath),
+      size: stat.size,
+      mtimeMs: stat.mtimeMs
+    };
+    const rs = fs.createReadStream(filePath);
+    await this.sendStreamToClient(clientId, rs, { ...options, meta });
+  }
+
+  /** Cancel a stream incoming from a client (server side) */
+  public async cancelIncomingStreamFromClient(clientId: string, streamId: string): Promise<void> {
+    if (!this.primaryChannel) return;
+    await (this.primaryChannel as any).cancelIncomingStream(streamId, { clientId });
+  }
+
+  /** Cancel a server->client outgoing stream */
+  public async cancelOutgoingStreamToClient(clientId: string, streamId: string): Promise<void> {
+    if (!this.primaryChannel) return;
+    await (this.primaryChannel as any).cancelOutgoingStream(streamId, { clientId });
   }
 
   /**
@@ -361,10 +471,9 @@ export class IpcServer extends plugins.EventEmitter {
   public async broadcast(type: string, payload: any, headers?: Record<string, any>): Promise<void> {
     const promises: Promise<void>[] = [];
 
-    for (const [clientId, client] of this.clients) {
+    for (const [clientId] of this.clients) {
       promises.push(
-        client.channel.sendMessage(type, payload, headers)
+        this.sendToClient(clientId, type, payload, headers).catch((error) => {
-          .catch((error) => {
           this.emit('error', error, clientId);
         })
       );
@@ -387,8 +496,7 @@ export class IpcServer extends plugins.EventEmitter {
     for (const [clientId, client] of this.clients) {
       if (filter(clientId, client.metadata)) {
         promises.push(
-          client.channel.sendMessage(type, payload, headers)
+          this.sendToClient(clientId, type, payload, headers).catch((error) => {
-            .catch((error) => {
             this.emit('error', error, clientId);
           })
         );
@@ -505,4 +613,11 @@ export class IpcServer extends plugins.EventEmitter {
       uptime: this.primaryChannel ? Date.now() - (this.primaryChannel as any).connectedAt : undefined
     };
   }
+
+  /**
+   * Check if server is ready to accept connections
+   */
+  public getIsReady(): boolean {
+    return this.isReady;
+  }
 }

ts/classes.transports.ts

@@ -18,6 +18,12 @@ export interface IIpcMessageEnvelope<T = any> {
 export interface IIpcTransportOptions {
   /** Unique identifier for this transport */
   id: string;
+  /**
+   * When true, a client transport will NOT auto-start a server when connect()
+   * encounters ECONNREFUSED/ENOENT. Useful for strict client/daemon setups.
+   * Default: false. Can also be overridden by env SMARTIPC_CLIENT_ONLY=1.
+   */
+  clientOnly?: boolean;
   /** Socket path for Unix domain sockets or pipe name for Windows */
   socketPath?: string;
   /** TCP host for network transport */
@@ -34,6 +40,10 @@ export interface IIpcTransportOptions {
   noDelay?: boolean;
   /** Maximum message size in bytes (default: 8MB) */
   maxMessageSize?: number;
+  /** Automatically cleanup stale socket file on start (default: false) */
+  autoCleanupSocketFile?: boolean;
+  /** Socket file permissions mode (e.g. 0o600) */
+  socketMode?: number;
 }
 
 /**
@@ -165,6 +175,8 @@ export class UnixSocketTransport extends IpcTransport {
   private socket: plugins.net.Socket | null = null;
   private server: plugins.net.Server | null = null;
   private clients: Set<plugins.net.Socket> = new Set();
+  private socketToClientId = new WeakMap<plugins.net.Socket, string>();
+  private clientIdToSocket = new Map<string, plugins.net.Socket>();
 
   /**
    * Connect as client or start as server
@@ -189,7 +201,21 @@ export class UnixSocketTransport extends IpcTransport {
 
       this.socket.on('error', (error: any) => {
         if (error.code === 'ECONNREFUSED' || error.code === 'ENOENT') {
-          // No server exists, we should become the server
+          // Determine if we must NOT auto-start server
+          const envVal = process.env.SMARTIPC_CLIENT_ONLY;
+          const envClientOnly = !!envVal && (envVal === '1' || envVal === 'true' || envVal === 'TRUE');
+          const clientOnly = this.options.clientOnly === true || envClientOnly;
+
+          if (clientOnly) {
+            // Reject instead of starting a server to avoid races
+            const reason = error.code || 'UNKNOWN';
+            const err = new Error(`Server not available (${reason}); clientOnly prevents auto-start`);
+            (err as any).code = reason;
+            reject(err);
+            return;
+          }
+
+          // No server exists and clientOnly is false: become the server (back-compat)
           this.socket = null;
           this.startServer(socketPath).then(resolve).catch(reject);
         } else {
@@ -206,12 +232,14 @@ export class UnixSocketTransport extends IpcTransport {
    */
   private async startServer(socketPath: string): Promise<void> {
     return new Promise((resolve, reject) => {
-      // Clean up stale socket file if it exists
+      // Clean up stale socket file if autoCleanupSocketFile is enabled
+      if (this.options.autoCleanupSocketFile) {
         try {
           plugins.fs.unlinkSync(socketPath);
         } catch (error) {
           // File doesn't exist, that's fine
         }
+      }
 
       this.server = plugins.net.createServer((socket) => {
         // Each new connection gets added to clients
@@ -233,7 +261,14 @@ export class UnixSocketTransport extends IpcTransport {
 
         socket.on('close', () => {
           this.clients.delete(socket);
-          this.emit('clientDisconnected', socket);
+          // Clean up clientId mappings
+          const clientId = this.socketToClientId.get(socket);
+          if (clientId && this.clientIdToSocket.get(clientId) === socket) {
+            this.clientIdToSocket.delete(clientId);
+          }
+          this.socketToClientId.delete(socket);
+          // Emit with clientId if known so higher layers can react
+          this.emit('clientDisconnected', socket, clientId);
         });
 
         socket.on('drain', () => {
@@ -247,6 +282,15 @@ export class UnixSocketTransport extends IpcTransport {
       this.server.on('error', reject);
 
       this.server.listen(socketPath, () => {
+        // Set socket permissions if specified
+        if (this.options.socketMode !== undefined && process.platform !== 'win32') {
+          try {
+            plugins.fs.chmodSync(socketPath, this.options.socketMode);
+          } catch (error) {
+            // Ignore permission errors, not critical
+          }
+        }
+        
         this.connected = true;
         this.emit('connect');
         resolve();
@@ -292,7 +336,18 @@ export class UnixSocketTransport extends IpcTransport {
           // Parse and emit the message with socket reference
           try {
             const message = JSON.parse(messageData.toString('utf8')) as IIpcMessageEnvelope;
+            
+            // Update clientId mapping
+            const clientId = message.headers?.clientId ?? 
+              (message.type === '__register__' ? (message.payload as any)?.clientId : undefined);
+            if (clientId) {
+              this.socketToClientId.set(socket, clientId);
+              this.clientIdToSocket.set(clientId, socket);
+            }
+            
+            // Emit both events so IpcChannel can process it
             this.emit('clientMessage', message, socket);
+            this.emit('message', message);
           } catch (error: any) {
             this.emit('error', new Error(`Failed to parse message: ${error.message}`));
           }
@@ -400,7 +455,33 @@ export class UnixSocketTransport extends IpcTransport {
         }
       });
     } else if (this.server && this.clients.size > 0) {
-      // Server mode - broadcast to all clients
+      // Server mode - route by clientId if present, otherwise broadcast
+      const targetClientId = message.headers?.clientId;
+      
+      if (targetClientId && this.clientIdToSocket.has(targetClientId)) {
+        // Send to specific client
+        const targetSocket = this.clientIdToSocket.get(targetClientId)!;
+        if (targetSocket && !targetSocket.destroyed) {
+          return new Promise((resolve) => {
+            const success = targetSocket.write(frame, (error) => {
+              if (error) {
+                resolve(false);
+              } else {
+                resolve(true);
+              }
+            });
+
+            if (!success) {
+              targetSocket.once('drain', () => resolve(true));
+            }
+          });
+        } else {
+          // Socket is destroyed, remove from mappings
+          this.clientIdToSocket.delete(targetClientId);
+          return false;
+        }
+      } else {
+        // Broadcast to all clients (fallback for messages without specific target)
         const promises: Promise<boolean>[] = [];
         
         for (const client of this.clients) {
@@ -422,6 +503,7 @@ export class UnixSocketTransport extends IpcTransport {
         const results = await Promise.all(promises);
         return results.every(r => r);
       }
+    }
 
     return false;
   }

ts/index.ts

@@ -6,8 +6,9 @@ export * from './classes.ipcclient.js';
 import { IpcServer } from './classes.ipcserver.js';
 import { IpcClient } from './classes.ipcclient.js';
 import { IpcChannel } from './classes.ipcchannel.js';
+import { stream as nodeStream, fs as nodeFs, path as nodePath } from './smartipc.plugins.js';
 import type { IIpcServerOptions } from './classes.ipcserver.js';
-import type { IIpcClientOptions } from './classes.ipcclient.js';
+import type { IIpcClientOptions, IConnectRetryConfig } from './classes.ipcclient.js';
 import type { IIpcChannelOptions } from './classes.ipcchannel.js';
 
 /**
@@ -17,6 +18,97 @@ export class SmartIpc {
   /**
    * Create an IPC server
    */
+  /**
+   * Wait for a server to become ready at the given socket path
+   */
+  public static async waitForServer(options: {
+    socketPath: string;
+    timeoutMs?: number;
+  }): Promise<void> {
+    const timeout = options.timeoutMs || 10000;
+    const startTime = Date.now();
+    
+    while (Date.now() - startTime < timeout) {
+      try {
+        // Create a temporary client with proper options
+        const testClient = SmartIpc.createClient({
+          id: 'test-probe',
+          socketPath: options.socketPath,
+          clientId: `probe-${process.pid}-${Date.now()}`,
+          heartbeat: false,
+          clientOnly: true,
+          connectRetry: {
+            enabled: false  // Don't retry, we're handling retries here
+          },
+          registerTimeoutMs: 2000  // Short timeout for quick probing
+        });
+        
+        // Try to connect and register with the server
+        await testClient.connect();
+        
+        // Success! Clean up and return
+        await testClient.disconnect();
+        return;
+      } catch (error) {
+        // Server not ready yet, wait and retry
+        await new Promise(resolve => setTimeout(resolve, 200));
+      }
+    }
+    
+    throw new Error(`Server not ready at ${options.socketPath} after ${timeout}ms`);
+  }
+
+  /**
+   * Helper to spawn a server process and connect a client
+   */
+  public static async spawnAndConnect(options: {
+    serverScript: string;
+    socketPath: string;
+    clientId?: string;
+    spawnOptions?: any;
+    connectRetry?: IConnectRetryConfig;
+    timeoutMs?: number;
+  }): Promise<{
+    client: IpcClient;
+    serverProcess: any;
+  }> {
+    const { spawn } = await import('child_process');
+    
+    // Spawn the server process
+    const serverProcess = spawn('node', [options.serverScript], {
+      detached: true,
+      stdio: 'pipe',
+      ...options.spawnOptions
+    });
+    
+    // Handle server process errors
+    serverProcess.on('error', (error: Error) => {
+      console.error('Server process error:', error);
+    });
+    
+    // Wait for server to be ready
+    await SmartIpc.waitForServer({
+      socketPath: options.socketPath,
+      timeoutMs: options.timeoutMs || 10000
+    });
+    
+    // Create and connect client
+    const client = new IpcClient({
+      id: options.clientId || 'test-client',
+      socketPath: options.socketPath,
+      connectRetry: options.connectRetry || {
+        enabled: true,
+        maxAttempts: 10,
+        initialDelay: 100,
+        maxDelay: 1000
+      }
+    });
+    
+    await client.connect({ waitForReady: true });
+    
+    return { client, serverProcess };
+  }
+
   public static createServer(options: IIpcServerOptions): IpcServer {
     return new IpcServer(options);
   }
@@ -38,3 +130,21 @@ export class SmartIpc {
 
 // Export the main class as default
 export default SmartIpc;
+
+/**
+ * Helper: pipe an incoming SmartIPC readable stream to a file path.
+ * Ensures directory exists; resolves on finish.
+ */
+export async function pipeStreamToFile(readable: NodeJS.ReadableStream, filePath: string): Promise<void> {
+  // Ensure directory exists
+  try {
+    nodeFs.mkdirSync(nodePath.dirname(filePath), { recursive: true });
+  } catch {}
+  await new Promise<void>((resolve, reject) => {
+    const ws = nodeFs.createWriteStream(filePath);
+    ws.on('finish', () => resolve());
+    ws.on('error', reject);
+    readable.on('error', reject);
+    (readable as any).pipe(ws);
+  });
+}

ts/smartipc.plugins.ts

@@ -11,6 +11,7 @@ import * as os from 'os';
 import * as path from 'path';
 import * as fs from 'fs';
 import * as crypto from 'crypto';
+import * as stream from 'stream';
 import { EventEmitter } from 'events';
 
-export { net, os, path, fs, crypto, EventEmitter };
+export { net, os, path, fs, crypto, stream, EventEmitter };