API Contract Analyzer
Lint an OpenAPI or Swagger spec for contract quality issues.
OpenAPI document
Paste JSON or YAML (OpenAPI 3.x / Swagger 2)
Contract report
Structure, documentation and safety checks
Orders API · v1.3.0 · parsed as YAML
- servers—No `servers` declared, so clients cannot infer a base URL.
- GET /orders—No 4xx error response documented.
- GET /orders—No security requirement — the operation is documented as public.
- POST /orders—No 4xx error response documented.
- POST /orders—POST has no request body schema.
- POST /orders—No security requirement — the operation is documented as public.
- GET /orders/{orderId}—No 4xx error response documented.
- GET /orders/{orderId}—No security requirement — the operation is documented as public.
- POST /refunds—No 4xx error response documented.
- POST /refunds—POST has no request body schema.
- POST /refunds—No security requirement — the operation is documented as public.
- info—No API description — useful for docs and SDK generation.
- info—No contact details declared.
- GET /orders—No tags, so docs cannot group this operation.
- POST /orders—No tags, so docs cannot group this operation.
- GET /orders/{orderId}—No tags, so docs cannot group this operation.
- POST /refunds—No tags, so docs cannot group this operation.
About the API Contract Analyzer
Paste an OpenAPI 3 or Swagger 2 document (JSON or YAML) and get a prioritised list of contract problems: missing operationIds, undocumented responses, absent security schemes, unversioned servers, missing descriptions and error responses. Everything is parsed locally in your browser.
Examples
OpenAPI 3 spec
openapi: 3.0.0 ...Output
12 findings: 3 errors, 5 warnings, 4 infoKeyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- Postman collections and OpenAPI: two views of the same API
A collection describes calls you make; a spec describes the contract you promise. Here is how to convert between them without losing the parts that matter.
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Version 1.0.0 · Updated 2026-08-20 · Runs entirely in your browser