Next.js

Use the NextEndpoint adapter to expose your agent network as a Next.js App Router API route.

Setup

1. Install m4trix:

pnpm add @m4trix/core

1. Create an API route (e.g. app/api/chat/route.ts):

import {
  AgentFactory,
  AgentNetwork,
  AgentNetworkEvent,
  NextEndpoint,
  S,
} from '@m4trix/core/matrix';

const requestEvent = AgentNetworkEvent.of('chat-request', S.Struct({ message: S.String }));
const responseEvent = AgentNetworkEvent.of('chat-response', S.Struct({ text: S.String, done: S.Boolean }));

const agent = AgentFactory.run()
  .listensTo([requestEvent])
  .emits([responseEvent])
  .logic(async ({ triggerEvent, emit }) => {
    emit({
      name: 'chat-response',
      payload: { text: `Echo: ${triggerEvent.payload.message}`, done: true },
    });
  })
  .produce({});

const network = AgentNetwork.setup(
  ({ mainChannel, createChannel, sink, registerAgent }) => {
    const main = mainChannel('main');
    const client = createChannel('client').sink(sink.httpStream());
    registerAgent(agent).subscribe(main).publishTo(client);
  },
);

const api = network.expose({
  protocol: 'sse',
  select: { channels: 'client' },
  startEventName: 'chat-request',
});

const handler = NextEndpoint.from(api).handler();
export const GET = handler;
export const POST = handler;

How It Works

1. Receives the incoming Request

2. Runs auth (if configured)

3. Extracts JSON payload from POST body (or empty object for GET)

4. Creates an SSE Response with streaming headers

5. Publishes the start event to the main channel

6. Streams matching events from the selected channels as SSE

GET vs POST

• GET — Payload can be passed as query params (e.g. ?payload={"message":"Hi"}). Useful for simple testing.

• POST — Payload in JSON body. Preferred for production.

Full Example with OpenAI Streaming

See IO + Adapters for a complete Next.js streaming example with OpenAI.