Fun Data Bridge API — free mock REST API for testing

Generate small deterministic JSON fixtures using fundata-style schemas, then reuse them in API tests.

The Fun Data Bridge generates seeded fixtures from a schema you supply — the same idea as the sibling site fundata.dev, exposed as an API. Given the same seed it returns the same data, which is what makes it usable as a fixture source for tests that must be deterministic rather than merely realistic.

Base URL: https://funapi.dev/api/data/v1 · 4 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/data/v1/types — List supported field types. No token, no signup:

curl -i https://funapi.dev/api/data/v1/types

answers 200 OK with:

{
  "data": [
    "row",
    "integer",
    "boolean",
    "email",
    "uuid",
    "name",
    "date",
    "string"
  ]
}

Open and run this endpoint

What you can practise here

• Generate with a fixed seed twice and confirm the output is byte-identical, then change the seed and confirm it is not.
• Post a schema with an unsupported field type and read the 422.
• Request a large batch and follow the 202 to the finished result.
• Feed the generated fixtures straight into another API in the catalog as request bodies.

generate

schemas and fixtures

• GET /data/v1/types — List supported field types · Responds with 200 Link to this endpoint
• POST /data/v1/generate — Generate deterministic JSON rows · Responds with 200 422 Link to this endpoint
• POST /data/v1/jobs — Queue a large fixture job (requires Bearer auth) · Responds with 202 422 Link to this endpoint
• GET /data/v1/jobs/{id} — Poll fixture job · Responds with 200 404 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

Last updated 6 September 2026