@hile/message-ws

Use MessageModem over WebSocket connections.

@hile/message-ws

Use MessageModem over WebSocket connections.

Choose This Package When

Use @hile/message-ws for: Use MessageModem over WebSocket connections.

Use When

Use the message packages for request/response messaging over WebSocket, process IPC, worker threads, file-system message handlers, service discovery, streaming RPC, and registry-backed pub/sub.

Do Not Use When

• Do not use stream() for normal single-result calls.
• Do not rely on message IDs for business idempotency. They are transport IDs.
• Use defineMicroMessage() for Micro business handlers; reserve generic defineMessage() for transport-neutral loaders.
• Do not pass zero, fractional, non-finite, or oversized message timeouts. Explicit timeout values must be safe integers from 1 through 2_147_483_647 milliseconds.

Install

pnpm add @hile/context @hile/micro @hile/message-loader @hile/message-ws

Use transport-specific packages only when you need to build custom IPC or worker-thread bridges.

Imports

import { defineMessage, MessageLoader } from '@hile/message-loader'
import { createExecutionContext } from '@hile/context'
import { Application, defineMicroMessage, Registry, Server } from '@hile/micro'
import { MessageWs } from '@hile/message-ws'
import { MessageIpc } from '@hile/message-ipc'
import { MessageWorkerThread } from '@hile/message-worker-thread'

Copy-Paste Example

Message handler file:

// src/messages/ping.msg.ts
import { defineMicroMessage } from '@hile/micro'

export default defineMicroMessage(async ({ data, params, invocation }) => {
  return {
    type: 'pong',
    data,
    params,
    requestId: invocation.context.values.requestId,
    timestamp: Date.now(),
  }
})

Microservice boot file:

// src/services/app.boot.ts
import { defineService } from '@hile/core'
import { Application } from '@hile/micro'

export default defineService('micro.app', async (shutdown) => {
  const app = new Application({
    namespace: process.env.MICRO_NAMESPACE ?? 'example.service',
    registry: {
      host: process.env.REGISTRY_HOST ?? '127.0.0.1',
      port: Number(process.env.REGISTRY_PORT ?? 9876),
    },
    advertiseHost: process.env.HILE_ADVERTISE_HOST ?? '127.0.0.1',
  })

  await app.load(new URL('../messages', import.meta.url).pathname)
  const stop = await app.listen(Number(process.env.MICRO_PORT ?? 0))
  shutdown(stop)
  return app
})

Caller:

import { randomUUID } from 'node:crypto'
import { createExecutionContext } from '@hile/context'

const context = createExecutionContext({ requestId: randomUUID() })
const result = await app.call('example.service', '/ping', { hello: 'world' }, { context })

More Examples

Streaming handler:

// src/messages/events.msg.ts
import { defineMicroMessage } from '@hile/micro'

export default defineMicroMessage(async function* ({ invocation }) {
  for (let i = 0; i < 3; i++) {
    yield { seq: i, requestId: invocation.context.values.requestId }
  }
})

Streaming caller:

const stream = await app.stream('example.service', '/events', {}, { context })
for await (const chunk of stream) {
  console.log(chunk)
}

Custom WebSocket modem:

import { MessageWs } from '@hile/message-ws'
import type WebSocket from 'ws'

class RpcWs extends MessageWs {
  constructor(ws: WebSocket, private readonly dispatch: (url: string, data: unknown) => Promise<unknown>) {
    super(ws)
  }

  protected exec(data: { url: string; data: unknown }) {
    return this.dispatch(data.url, data.data)
  }

  request<T>(url: string, data: unknown, timeout = 30_000) {
    return this._send<T>({ url, data }, { timeout })
  }
}

Notice that request() returns a Promise<T>. Await it directly.

Runtime And Lifecycle Notes

• MessageLoader maps *.msg.* files to routes using @hile/loader.
• MessageLoader.dispatch(path, data, extras?) invokes the matched handler.
• MessageModem._send() returns a Promise.
• MessageModem._send() and _push() use a 30_000 ms timeout when none is provided. An explicit timeout must be a safe integer from 1 through 2_147_483_647; invalid values throw TypeError before a message is sent.
• MessageModem._stream() returns a Node Readable in object mode.
• Stream timeout and idleTimeout values use the same 1 through 2_147_483_647 ms range. The stream window must be a safe integer from 1 through 64 and defaults to 1.
• Each modem schedules request, total-stream, and idle-stream deadlines through one internal deadline scheduler. This reduces active Node.js timers without changing timeout, cancellation, ordering, or error semantics.
• @hile/message-ws keeps public decodeMessageFrame() payloads isolated from caller-owned input by default. Its owned WebSocket RawData path uses a zero-copy binary Flight payload view internally.
• A stream request requires exec() to return an async iterable.
• Application.call(namespace, url, data, options) requires options.context and returns a promise.
• Application.stream(namespace, url, data, options) requires options.context and returns a readable stream.
• Application.publish(topic, payload) returns an object with update() and unpublish().
• Application.subscribe(topic, callback) returns an unsubscribe function.
• Registry stores service addresses and retained config/topic state under ~/.registry.

Anti-Patterns

• Appending a secondary response getter to client.request('/x', data)
• Returning a plain object from a handler called through stream().
• Using pub/sub as a durable queue.
• Forgetting to register shutdown(await app.listen(...)).

Verification Checklist

• Micro message files default-export defineMicroMessage(...) and receive invocation.context.
• RPC callers use await app.call(..., { context }).
• Streaming handlers are async generators.
• Custom modem timeout values use the documented safe-integer range.
• Registry is started before application nodes need discovery.
• Micro apps use stable namespaces and advertise reachable hosts.

Related Recipes

Micro RPC With Message Loader

Complete Example

Provider handler:

// src/messages/charge.msg.ts
import { defineMicroMessage } from '@hile/micro'

export default defineMicroMessage(async ({ data, invocation }) => {
  return { charged: true, input: data, requestId: invocation.context.values.requestId }
})

Provider boot:

// src/services/app.boot.ts
import { defineService } from '@hile/core'
import { Application } from '@hile/micro'

export default defineService('billing.micro', async (shutdown) => {
  const app = new Application({
    namespace: 'billing',
    registry: { host: '127.0.0.1', port: 9876 },
    advertiseHost: '127.0.0.1',
  })

  await app.load(new URL('../messages', import.meta.url).pathname)
  const stop = await app.listen(9101)
  shutdown(stop)
  return app
})

Consumer:

import { randomUUID } from 'node:crypto'
import { createExecutionContext } from '@hile/context'

const context = createExecutionContext({ requestId: randomUUID(), tenantId: 't1' })
const result = await app.call('billing', '/charge', {
  tenantId: 't1',
  amount: 100,
}, { context })

Package-Local AI Guide

This package also ships AI.md in npm so agents can read accurate examples after installation.