Sherlock Holmes API — free mock REST API for testing

Cases, suspects and clues from a fictional Victorian detective agency. Practice CRUD, Bearer auth, nested resources, pagination and optimistic concurrency.

The Sherlock Holmes API is a case file: investigations with suspects and clues, and cases that move from open to solved. It is the catalog's PATCH endpoint — partial updates rather than whole-object PUTs — which is where most clients quietly send the wrong thing and never find out.

Base URL: https://funapi.dev/api/holmes/v1 · 10 endpoints · OpenAPI 3.1 spec and Postman collection available. New here? Read the getting started guide.

What you can practise here

• PATCH a single field on a case and confirm the untouched fields survive, which a careless PUT would have wiped.
• Close a case that is already closed and read the 409 rather than assuming the operation is idempotent.
• Add a clue to a case that does not exist and check the 404 comes from the parent, not the child.
• Attach a suspect twice and see how the API reports the duplicate.

cases

five cases, two still open

• GET /holmes/v1/cases — List all cases
• GET /holmes/v1/cases/{id} — Get one case
• GET /holmes/v1/cases/{id}/suspects — Get all suspects for a case (nested resource)
• PATCH /holmes/v1/cases/{id} — Update a case status (409 if unchanged) (requires Bearer auth)

suspects

alibis included, guilt undisclosed

• GET /holmes/v1/suspects/{id} — Get one suspect
• POST /holmes/v1/suspects — Add a suspect to a case (requires Bearer auth)
• PUT /holmes/v1/suspects/{id} — Update a suspect (requires Bearer auth)
• DELETE /holmes/v1/suspects/{id} — Clear a suspect (requires Bearer auth)

clues

physical, document, and testimony

• GET /holmes/v1/clues — List clues, filter by case or type
• GET /holmes/v1/clues/random — A random clue

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