Event Streams API — free mock REST API for testing

Practice event-stream consumers, Last-Event-ID resume behavior, duplicates and out-of-order detection.

The Event Streams API serves Server-Sent Events with replay cursors, heartbeats and guaranteed ordering. Streaming is where test suites usually stop, because a long-lived response is awkward to assert on — this one is built to make that assertable, with a Last-Event-ID cursor you can reconnect from.

Base URL: https://funapi.dev/api/streams/v1 · 3 endpoints · OpenAPI 3.1 spec and Postman collection available. New here? Read the getting started guide.

Example request and response

GET https://funapi.dev/api/streams/v1/events — Read events as JSON or text/event-stream. No token, no signup:

curl -i https://funapi.dev/api/streams/v1/events

answers 200 OK with:

{
  "total": 12,
  "data": [
    {
      "id": 1,
      "type": "lap.completed",
      "lap": 1,
      "position": 1
    },
    {
      "id": 2,
      "type": "lap.completed",
      "lap": 2,
      "position": 2
    },
    {
      "id": 3,
      "type": "lap.completed",
      "lap": 3,
      "position": 3
    },
    {
      "id": 4,
      "type": "lap.completed",
      "lap": 4,
      "position": 4
    },
    {
      "id": 5,
      "type": "lap.completed",
      "lap": 5,
      "position": 1
    },
    {
      "id": 6,
      "type": "lap.completed",
      "lap": 6,
      "position": 2
    },
    {
      "id": 7,
      "type": "lap.completed",
      "lap": 7,
      "position": 3
    },
    {
      "id": 8,
      "type": "lap.completed",
      "lap": 8,
      "position": 4
    },
    {
      "id": 9,
      "type": "lap.completed",
      "lap": 9,
      "position": 1
    },
    {
      "id": 10,
      "type": "lap.completed",
      "lap": 10,
      "position": 2
    },
    {
      "id": 11,
      "type": "lap.completed",
      "lap": 11,
      "position": 3
    },
    {
      "id": 12,

(truncated — the full response comes back when you run it)

Open and run this endpoint

What you can practise here

• Open the stream, drop the connection, and reconnect with Last-Event-ID to confirm no event was lost.
• Assert that events arrive in order under a burst rather than only at rest.
• Watch the heartbeat and set your idle timeout above it, not below.
• Publish an event and check how quickly it appears to a connected consumer.

events

stream and replay

• GET /streams/v1/events — Read events as JSON or text/event-stream · Responds with 200 Link to this endpoint
• GET /streams/v1/events/{id} — Replay one event by id · Responds with 200 404 Link to this endpoint
• POST /streams/v1/events — Publish a custom event (requires Bearer auth) · Responds with 202 Link to this endpoint

Related APIs

• Auth Playground API — OAuth 2.0 flows — client credentials, auth code, refresh & expiry.
• Webhooks API — Register callbacks, trigger events, inspect & replay deliveries.
• Protocol Lab API — Async jobs, redirects, 503/504, JSON Patch & content negotiation.
• Object Storage API — Objects, checksums, ranges & resumable uploads.

All 39 mock REST APIs

Use this response elsewhere

• JSON to TypeScript on fundata.dev — an interface for this response
• JSON to Zod on fundata.dev — a runtime validator for it
• mock API data on fundata.dev — thousands of records of the same shape for your own fixtures

Last updated 2 October 2026