---
title: "Consuming messages"
description: "Consuming messages — Node.js BabelQueue SDK (1.x)."
source: https://babelqueue.com/docs/babelqueue-node/1.x/consuming-messages/
updated: 2026-06-06T00:00:00.000Z
---

# Consuming messages

Pull the bytes from your broker, `decode` them, gate with `accepts` (a TypeScript
type guard), then switch on the URN — regardless of which language produced the
message. `trace_id` carries the cross-service correlation id.

```ts
import { EnvelopeCodec } from "@babelqueue/core";

// body pulled from your broker (Redis BLPOP, an AMQP message, …)
const incoming = EnvelopeCodec.decode(body);
if (EnvelopeCodec.accepts(incoming)) {
  // `incoming` is now narrowed to a fully-typed Envelope
  switch (EnvelopeCodec.urn(incoming)) {
    case "urn:babel:orders:created":
      console.log(`[${incoming.trace_id}] order received`, incoming.data);
      break;
  }
}
```

That's the whole loop: any producer, any consumer, one schema.