A TypeScript library for creating typed WebSocket connections with bi-directional communication support. Extends @api.global/typedrequest to bring type-safe request/response patterns to WebSocket connections.

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Features

🔒 Full Type Safety - Leverages TypeScript for compile-time checking of all request/response payloads
🔄 Bi-directional Communication - Both server and client can initiate requests
🔌 Auto-reconnect - Client automatically reconnects on connection loss
🏷️ Connection Tagging - Tag and filter connections for targeted messaging
🌐 Browser Compatible - Works in both Node.js and browser environments
🚀 SmartServe Integration - Native support for SmartServe's WebSocket handling

Install

npm install @api.global/typedsocket

Or with pnpm:

pnpm add @api.global/typedsocket

Usage

Prerequisites

TypeScript project setup
Basic understanding of async/await patterns
Familiarity with @api.global/typedrequest concepts

Define Your Request Interface

First, define the typed request interface that both client and server will use:

import * as typedrequestInterfaces from '@api.global/typedrequest-interfaces';

interface IGreetingRequest extends typedrequestInterfaces.implementsTR<
  typedrequestInterfaces.ITypedRequest,
  IGreetingRequest
> {
  method: 'greet';
  request: {
    name: string;
  };
  response: {
    message: string;
  };
}

Server Setup

TypedSocket composes its private protocol handlers into the application router before that router is given to SmartServe:

import { TypedSocket } from '@api.global/typedsocket';
import * as typedrequest from '@api.global/typedrequest';
import { SmartServe } from '@push.rocks/smartserve';

// Create the router and add handlers
const typedRouter = new typedrequest.TypedRouter();

typedRouter.addTypedHandler<IGreetingRequest>(
  new typedrequest.TypedHandler('greet', async (requestData) => {
    return {
      message: `Hello, ${requestData.name}! 👋`,
    };
  })
);

const server = TypedSocket.createServer(typedRouter);
const smartServe = new SmartServe({
  port: 3000,
  websocket: {
    typedRouter,
  },
});
server.attachSmartServe(smartServe);
await smartServe.start();

Integration with SmartServe

For SmartServe-based applications, compose the protocol router synchronously, attach the transport, and then start listening:

import { TypedSocket } from '@api.global/typedsocket';
import { SmartServe } from '@push.rocks/smartserve';
import * as typedrequest from '@api.global/typedrequest';

const typedRouter = new typedrequest.TypedRouter();

// Add handlers for client-to-server requests
typedRouter.addTypedHandler<IGreetingRequest>(
  new typedrequest.TypedHandler('greet', async (requestData) => {
    return { message: `Hello, ${requestData.name}!` };
  })
);

const typedSocket = TypedSocket.createServer(typedRouter);

// Create SmartServe with the composed application router
const smartServe = new SmartServe({
  port: 3000,
  websocket: {
    typedRouter,
    onConnectionOpen: (peer) => {
      // Tag connections for later filtering
      peer.tags.add('client');
    }
  }
});

typedSocket.attachSmartServe(smartServe);
await smartServe.start();

// Push notifications to tagged clients
const clients = await typedSocket.findAllTargetConnectionsByTag('client');
for (const client of clients) {
  const request = typedSocket.createTypedRequest<IGreetingRequest>('greet', client);
  await request.fire({ name: 'server' });
}

Note: When using SmartServe, the WebSocket transport is managed by SmartServe. TypedSocket acts as a convenience layer for finding connections and sending server-initiated requests.

Multiple isolated application routers can share one transport without becoming reachable from each other:

const typedSocket = TypedSocket.createServer([publicRouter, adminRouter]);
const smartServe = new SmartServe({
  port: 3000,
  authorityValidation: 'strict',
  websocket: {
    resolveTypedRouter: (context) => {
      if (context.url.hostname === 'example.com') return publicRouter;
      if (context.url.hostname === 'admin.example.com') return adminRouter;
      return undefined;
    },
  },
});
typedSocket.attachSmartServe(smartServe);
await smartServe.start();

TypedSocket adds a private, one-way fallback router containing its protocol handlers to every application router. Duplicate protocol method names are rejected during composition and on later router mutations; stop() releases the owned fallback edges. fromSmartServe() remains available as a compatibility shortcut that delegates to createServer() and attachSmartServe().

Connection lookup and implicit single-peer targeting span every peer on the attached SmartServe transport, regardless of the surface router that accepted the peer. Multi-surface servers should tag or filter peers by surface and pass an explicit target to createTypedRequest().

Client Setup

Connect to the WebSocket server from a client:

import { TypedSocket } from '@api.global/typedsocket';
import * as typedrequest from '@api.global/typedrequest';

// Create a router for handling server-initiated requests (if needed)
const clientRouter = new typedrequest.TypedRouter();

// Connect to the server
const client = await TypedSocket.createClient(
  clientRouter,
  'http://localhost:3000'
);

Abortable Startup

Pass an AbortSignal when startup or reconnect attempts must be cancellable. Aborting stops the in-flight WebSocket and prevents queued reconnect attempts from continuing.

const abortController = new AbortController();

const clientPromise = TypedSocket.createClient(
  clientRouter,
  'http://localhost:3000',
  {
    abortSignal: abortController.signal,
    initialBackoffMs: 1000,
    maxRetries: 10,
  }
);

// Later, if the connection attempt should no longer continue:
abortController.abort();

try {
  const client = await clientPromise;
} catch (error) {
  // Startup was aborted before a stable connection was established.
}

Using Window Location (Browser)

In browser environments, you can automatically use the current page's origin:

const client = await TypedSocket.createClient(
  clientRouter,
  TypedSocket.useWindowLocationOriginUrl()
);

Sending Requests

Client to Server

const request = client.createTypedRequest<IGreetingRequest>('greet');
const response = await request.fire({
  name: 'World',
});

console.log(response.message); // "Hello, World! 👋"

Server to Client

The server can also initiate requests to connected clients:

// When only one client is connected, it's automatically selected
const request = server.createTypedRequest<IGreetingRequest>('greet');
const response = await request.fire({
  name: 'Client',
});

// For multiple clients, specify the target connection
const connection = await server.findTargetConnection(async (conn) => {
  // Your filter logic here
  return true;
});
const targetedRequest = server.createTypedRequest<IGreetingRequest>('greet', connection);

Request Deadlines and Cancellation

TypedSocket forwards both configured request cancellation and per-fire() deadlines to its client and SmartServe server transports. The first timeout or abort to occur cancels the transport work and cleans the pending request state.

const requestAbort = new AbortController();
const request = client.createTypedRequest<IGreetingRequest>(
  'greet',
  undefined,
  {
    timeoutMs: 10_000,
    abortSignal: requestAbort.signal,
  }
);

const responsePromise = request.fire(
  { name: 'World' },
  { timeoutMs: 3_000 }
);

// A lifecycle owner can independently cancel before either timeout:
// requestAbort.abort();
const response = await responsePromise;

Connection Tagging

Tag connections for organized, targeted communication:

// Client side: add a tag
interface IUserTag extends typedrequestInterfaces.ITag {
  name: 'userRole';
  payload: 'admin' | 'user' | 'guest';
}

await client.setTag<IUserTag>('userRole', 'admin');

// On reconnect, stored tags are restored before statusSubject emits
// "connected". A failed restoration keeps the client unready and is retried
// through the normal reconnect policy.

// Removed tags are not restored after reconnect, even if this rejects because
// the server is unavailable while the removal request is attempted.
await client.removeTag('userRole');

// Server side: find connections by tag
const adminConnections = await server.findAllTargetConnectionsByTag<IUserTag>(
  'userRole',
  'admin'
);

// Send to all admins
for (const conn of adminConnections) {
  const request = server.createTypedRequest<IGreetingRequest>('greet', conn);
  await request.fire({ name: 'admin' });
}

// Find a single connection
const firstAdmin = await server.findTargetConnectionByTag<IUserTag>('userRole', 'admin');

Event Handling

Subscribe to connection status events:

client.statusSubject.subscribe((status) => {
  console.log('Connection status:', status);
});

server.statusSubject.subscribe((status) => {
  console.log('Server connection event:', status);
});

Cleanup

Properly close connections when done:

// Client
await client.stop();

// Server integration
await typedSocket.stop();
await smartServe.stop();

API Reference

TypedSocket

Static Methods

Method	Description
`createClient(router, serverUrl, options?)`	Creates a WebSocket client that connects to the specified server URL. Options include `autoReconnect`, `maxRetries`, `initialBackoffMs`, `maxBackoffMs`, and `abortSignal`.
`createServer(routerOrRouters)`	Synchronously composes TypedSocket protocol handling into one or more isolated application routers.
`fromSmartServe(smartServe, routerOrRouters)`	Compatibility shortcut that creates and attaches a server-side TypedSocket.
`useWindowLocationOriginUrl()`	Returns the current window location origin (browser only).

Instance Properties

Property	Description
`side`	Whether this instance is a `'server'` or `'client'`.
`typedrouter`	The TypedRouter instance handling requests.
`statusSubject`	RxJS Subject for connection status events.

Instance Methods

Method	Description
`attachSmartServe(smartServe)`	Attaches one SmartServe transport to a composed server-side TypedSocket before listening.
`createTypedRequest(method, targetConnection?, options?)`	Creates a typed request. Options include the transport `timeoutMs` and `abortSignal`; per-call `fire()` deadlines are also forwarded to the transport.
`setTag(name, payload)`	Sets a tag on the client connection (client-side only).
`removeTag(name)`	Immediately removes a tag from local reconnect state, then removes it from the server connection; rejects if the server removal fails.
`findAllTargetConnections(filterFn)`	Finds all connections matching the filter (server-side only).
`findTargetConnection(filterFn)`	Finds the first connection matching the filter (server-side only).
`findAllTargetConnectionsByTag(key, payload?)`	Finds all connections with the specified tag.
`findTargetConnectionByTag(key, payload?)`	Finds the first connection with the specified tag.
`stop()`	On clients, closes the WebSocket and rejects pending requests. On servers, cancels pending requests, cleans their interests, unsubscribes from SmartServe, and releases protocol-router composition without stopping SmartServe itself.

License and Legal Information

This repository contains open-source code licensed under the MIT License. A copy of the license can be found in the license file.

Please note: The MIT License does not grant permission to use the trade names, trademarks, service marks, or product names of the project, except as required for reasonable and customary use in describing the origin of the work and reproducing the content of the NOTICE file.

Trademarks

This project is owned and maintained by Task Venture Capital GmbH. The names and logos associated with Task Venture Capital GmbH and any related products or services are trademarks of Task Venture Capital GmbH or third parties, and are not included within the scope of the MIT license granted herein.

Use of these trademarks must comply with Task Venture Capital GmbH's Trademark Guidelines or the guidelines of the respective third-party owners, and any usage must be approved in writing. Third-party trademarks used herein are the property of their respective owners and used only in a descriptive manner, e.g. for an implementation of an API or similar.

readme.md

@api.global/typedsocket