Mock any API in seconds
The Hono-based engine handles $ref dereferencing, per-endpoint overrides, conditional response rules, request validation, and response multipliers. Mock definitions live in the synced workspace so teammates share them; the runtime stays on your machine.
One engine, three runtimes
The same factory powers the desktop mock manager, the apicircle CLI, and the MCP mock.start tool — start a mock from the app, your terminal, or an AI client.
Realistic behaviour
Per-endpoint overrides, conditional response rules, request-schema validation, and response multipliers let you simulate the failure modes your real API has.
Shared definitions, local runtime
Mock definitions sync in the workspace JSON so the whole team gets them; the running server binds to localhost on your machine only.
Get going in one command
Start a mock straight from a spec file — no workspace required.
$ npx @apicircle/cli mock ./openapi.yamlBring your APIs under version control
Open the web app in your browser, or grab the desktop build. No account, no setup — your first workspace is created the moment you arrive.