OpenAPI Compatibility Checker
Compare two OpenAPI 3.x specifications locally and review potentially breaking API contract changes by operation and field path.
DeveloperProcessed locally
OpenAPI Test Scenario Generator
Draft request examples and negative contract test scenarios from OpenAPI constraints, locally.
Processed on this page. No uploads. Your input is not saved.
Turn an OpenAPI specification into reviewable request examples and negative test scenarios. Your specification stays in this browser.
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.
Generated scenarios
These are drafts derived from the specification, not verified tests. This tool never calls an API. Review examples and use a safe test environment before running requests.
What does the generator create?
It creates one minimal request example per path operation and up to three negative cases from documented required fields, parameters, enums and simple bounds. Declared response codes are shown as references, not guaranteed outcomes.
What needs review?
Generated values cannot know valid account IDs, business rules, credentials or production-safe data. Complex schemas, external references, custom formats and patterns may need hand-written examples. No server URL or authentication secret is included.
How do I use the output?
Download the JSON scenario pack for structured data or Markdown for a review checklist. Adapt every case to your API and run it only against a safe test environment. The tool does not execute requests.
Draft API test scenarios from OpenAPI
Paste or choose one OpenAPI 3.0, 3.1 or 3.2 file. Generate a minimal request example for each path operation and up to three negative cases based on documented required values, enums and simple bounds. Download a JSON scenario pack or Markdown checklist.
Example and expected result
A POST /pets schema requires `name` and limits `age` to 0–30. The generator drafts one valid body, a case that omits `name`, and a case that uses an out-of-range age. These are review drafts: the tool never calls your API, does not add credentials, and cannot infer safe real identifiers or business rules.