Developers · Mocks

Real-shaped responses. Without standing up a backend.

Apinizer's Mock API serves conditional, dynamic responses on the same gateway as the real APIs. Frontends, partners, and contract tests unblock in minutes — and the mock graduates to production-flavored when the backend ships.

Five-minute quickstart Open Mock API

Mock APIs — For developers use case overview from Apinizer. — For developers · Mock APIs

The problem

Most projects burn weeks waiting for backends.

Frontend teams wait for services. Partners wait for endpoints. Test suites wait for fixtures. Each team improvises — postman mocks, local stubs, hand-typed JSON — and reality drifts from the contract. Apinizer's Mock API lives on the same gateway as production, follows the same OpenAPI, and graduates without a rewrite when the real service ships.

Capabilities

What Apinizer does here

Conditional responses

Different responses by parameter, header, or consumer. Mock the happy path, the empty list, the rate-limit, the 5xx — all from the same endpoint.

Dynamic data

Templated bodies with random, sequential, or referenced data. Each call returns plausibly different content — the way a real service does.

OpenAPI-shaped

Mocks declared against the same OpenAPI spec the real service will implement. Contract drift becomes impossible.

Graduates to production

When the real backend lands, swap the mock binding for the live binding. Consumers don't notice the cutover.

Contract-test friendly

Test suites hit the mock in CI; mock validates request shape; failed contracts caught in PR, not in staging.

Same governance

Auth, rate limit, audit — applied to mocks the same way as production. Mocks aren't a backdoor; they're a managed endpoint.

Use cases

In production, this looks like…

Banking
Istanbul bank unblocks mobile team 5 sprints before backend ships
Mock endpoints cover the new payments flow. Mobile delivers screens; partner SDKs land; backend graduates the mock when it's ready.
Manufacturing
Munich OEM ships partner SDKs against mock endpoints
Supplier integrations onboard on mocks. The real production service swaps in on cutover day; no SDK change.
Public sector
Stockholm agency runs contract tests against mocks in CI
Every PR runs against the OpenAPI-shaped mock. Contract regressions caught before review; fewer staging surprises.
Retail
Madrid retailer prototypes a personalization API with conditional mocks
Conditional logic returns different recommendations by consumer ID. Marketing tests campaigns; engineering ships the real service second.
Insurance
Milan insurer mocks rate-limit and 5xx responses for resilience testing
Test suites exercise client behavior under rate-limit, partial failure, and timeout — driven by the gateway's mock conditions.
Telecom
Amsterdam carrier onboards partner B2B mocks for early integration
Partners hit mock endpoints months before launch. Real endpoints swap in on day-of; partner integration unchanged.
Healthcare
Prague hospital unblocks FHIR client work with mock servers
Clinical apps build against FHIR-shaped mocks. Real EHR integration lands later; the consumer code is already correct.
Government
Baku ministry runs a hackathon on mock-only endpoints
Hackathon teams build against mocks; winners get production access. The mock-to-production graduation is one binding swap.