How does the api-contract-tester differ from a standard API client?

This skill automatically transforms OpenAPI/Swagger specs or Postman collections into deep test suites that cover edge cases, security vulnerabilities, and schema constraints that manual testing often misses.

Which testing frameworks can I use the generated code with?

The skill is framework-agnostic and can generate fully functional test code for Jest, Pytest, Vitest, Playwright, and even raw curl scripts for CI/CD pipelines.

Can this skill help me detect breaking changes between API versions?

Absolutely. It is specifically designed to perform regression testing by comparing different versions of an API to detect breaking changes, type shifts, or missing fields.

What specific security and edge-case scenarios does the skill cover?

Beyond simple '200 OK' checks, it automatically generates tests for unauthorized access, malformed tokens, rate-limiting headers, and boundary-value analysis for input fields.

What exactly is included with the purchase of this skill?

You get the full capability to parse documentation into test suites, generation of code for your chosen framework, and a comprehensive markdown coverage report.

What information do I need to provide to generate a test suite?

To get started, simply provide your OpenAPI specification (JSON/YAML) or a Postman collection link, and specify your preferred testing framework (e.g., Pytest or Jest).

Api Contract Tester

Turn OpenAPI specs into exhaustive, framework-ready test suites covering happy paths, edge cases, and security gaps.

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api-contract-tester

Example session with this skill installed

I need to test the user registration endpoint at /v1/users. Can you generate some Jest tests to validate the request body, specifically focusing on email validation errors?

Read your context and instructions
Compiled the api-contract-tester

"test_user_registration_invalid_email":

  it("returns 422 when email is missing '@'", async () => {
    const res = await request(app).post("/v1/users").send({ email: "bad-email" });
    expect(res.status).toBe(422);
    expect(res.body.errors).toContainEqual(expect.objectContaining({ field: "email" }));
  });

Connects securely to your tools. The creator never sees your data.

What you get

Generate framework-ready test suites from OpenAPI specificationsIdentify boundary conditions and off-by-one errors in API endpointsDetect authentication vulnerabilities and security gaps in contract logicVerify schema compliance against production-ready regression suites

About this skill

Exhaustive API Contract & Regression Testing

Transform your OpenAPI specs or Postman collections into professional-grade test suites. Unlike basic tools that only check for "200 OK" responses, this skill acts as a senior quality engineer to probe the boundaries of your API. It identifies off-by-one errors, authentication vulnerabilities, and schema mismatches before they reach production.

What it does

Parse & Analyze: Extracts endpoints, schemas, and constraints from OpenAPI/Swagger, Postman, or raw code.
Constraint Testing: Generates tests for min/max values, regex patterns, and enum boundaries.
Security First: Automatically builds suites for missing tokens, malformed JWTs, and unauthorized cross-user access.
Robust Validation: Checks for breaking changes between versions, including field removals and type shifts.
Framework Flexibility: Generates code for Jest, Pytest, Vitest, Playwright, or curl scripts.

Why use this skill

Writing comprehensive API tests is tedious and manual. This skill automates the creation of "the tests developers forget"—such as testing rate-limit headers, pagination boundaries, and SQL injection strings. It ensures consistent error response formats and prevents internal stack traces from leaking to users. The result is a production-ready test suite with a detailed coverage report across 10 distinct categories.

Supported Outputs

JavaScript/TypeScript: Jest, Vitest, Supertest, Playwright.
Python: Pytest with requests or httpx.
DevOps: Shell scripts using curl with assertions.
Reporting: Markdown-based coverage reports across happy paths, auth, and edge cases.

How to install

Works the same in every agent - Claude, Cursor, Codex, Copilot and 20+ more.

~30 seconds

1
Download the ZIP
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2
Unzip into your skills folder
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3
Ask your agent to use it
Restart the agent if it was already running. It picks the skill up automatically - no config needed.

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Click the path to copy it. Create the folder if it does not exist yet.

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