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API Endpoint Linter

Lint your OpenAPI spec for REST convention violations — free

Paste or upload an OpenAPI 3.x YAML/JSON spec and get a list of REST anti-patterns, naming issues, missing status codes, and security oversights.

Get your result in under 10 seconds.

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Example output

REST Convention Check:Flags non-plural resource names, wrong HTTP verbs, and missing idempotency headers.

Status Code Audit:Checks that each endpoint declares 400, 401, 404, and 500 responses where expected.

Security Scheme Validation:Warns if endpoints are missing auth scheme declarations or use deprecated HTTP Basic.

How It Works

Copy and paste your data into the input field

Instant results in under 10 seconds

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API design inconsistencies cause SDK breakage and developer frustration

Manual spec review catches maybe 30% of issues before production

Flags non-plural resource names, wrong HTTP verbs, and missing idempotency headers.

Checks that each endpoint declares 400, 401, 404, and 500 responses where expected.

Warns if endpoints are missing auth scheme declarations or use deprecated HTTP Basic.

Detects mixed camelCase/snake_case in parameter and property names across the spec.

Every result gets a unique shareable link. Show your colleagues.

owlematic.pro/share/abc123

Want more?

This tool is free forever. For advanced features and automation, check out our pro products.

Does it support OpenAPI 2 (Swagger)?

Not yet — OpenAPI 3.0 and 3.1 are fully supported. Swagger 2 support is planned.

Is my spec stored?

All linting runs in-browser. Your spec is never sent to a server.