Counterfact

Turns an OpenAPI spec into a stateful, editable local mock API with hot reload and a REPL.

PlatformWebfree

Counterfact turns an OpenAPI document into an editable, stateful local API server with hot reload, a REPL, and typed TypeScript handlers. It helps development teams build against a backend before it exists, or create deterministic, repeatable test fixtures. Built for developers and QA engineers who need a fast local or CI-friendly API simulation.

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Full match profile

Behind the summary, Matchbox keeps a richer profile of Counterfact - the signals our matcher actually reads to decide when to surface it. It stays private; claim the listing to see and control it.

Problem & pain-point mapping
Who we surface it to (audience fit)
What it's a strong alternative to
Trust & credibility signals

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