OpenAPI Test Scenario Generator
Draft request examples and negative contract test scenarios from OpenAPI constraints, locally.
DeveloperProcessed locally
OpenAPI Parameter Serialization Lab
Preview how OpenAPI path, query, header and cookie parameters serialize according to style and explode settings, locally.
Processed on this page. No uploads. Your input is not saved.
Load an OpenAPI document, choose an operation, then preview how its parameters become a request target, headers and cookies. No request is sent.
Paste JSON or YAML below, or choose a file.
Up to 2 MB and 300 path operations. Supports OpenAPI 3.0, 3.1 and 3.2. External references are not fetched.
Choose an operation
This operation has no parameters. The path can still be previewed.
Local preview only
Serialized request
Request target
Headers
Cookie header
What does this tool serialize?
It applies OpenAPI style and explode settings to path, query, header and cookie parameters. Supported common styles include simple, label, matrix, form, spaceDelimited, pipeDelimited and deepObject.
What needs manual review?
Content-based parameters, nested arrays or objects, undefined style combinations and external references are not guessed. Header values are shown without URI encoding because header quoting rules depend on the header. The schema is not validated.
Does it call the API?
No. The tool only creates a local preview for the selected operation. It does not resolve servers, add authentication or send network requests.
Check how an API parameter appears on the wire
Paste or choose an OpenAPI 3.0, 3.1 or 3.2 document, inspect it, select a path operation and adjust each JSON parameter value. Preview the path, query string, headers and cookies, then copy the parts you need.
Example and expected result
For GET /users/{id}, a query array `tag: [api, local]` with `style: form` and `explode: true` becomes `tag=api&tag=local`. A scalar path value is encoded before it is inserted into the path. The tool does not validate the schema or send a request; unsupported content encodings, nested values and external references are left for manual review.