Name: API Contract Tester
Price: 5 USD
Availability: InStock
Author: Agensi

See it in action

You say

Generate a Jest and Supertest suite for my users.yaml OpenAPI spec. It uses Bearer token auth. Ensure we test that a user can't read another user's profile.

Your agent does

I've generated a 12-test suite.

| Endpoint | Method | Case | Assertion | Test ID | |---|---|---|---|---| | /users/{id} | GET | IDOR | 403 on different user's ID | T-009 |

test('GET /users/:id - IDOR protection', async () => {
  const res = await request(app)
    .get('/users/999')
    .set('Authorization', `Bearer ${userAToken}`);
  expect(res.status).toBe(403);
});

What you get

Generate framework-ready test suites from OpenAPI or Swagger specs.Audit existing test suites to identify untested paths and schema drift.Create negative test cases for every validation constraint in your API.Verify authorization and IDOR protection across all protected endpoints.Produce a coverage matrix mapping endpoints to specific test IDs.

About this skill

Streamline Your API Reliability

The API Contract Tester is a specialized skill for developers and QA engineers who need to move beyond basic smoke tests. It transforms OpenAPI/Swagger specifications into exhaustive, framework-ready test suites that cover the "dark corners" of your API—validation logic, authz boundaries, and schema conformance.

What it does

This skill operates in two high-impact modes:

GENERATE: Builds a complete test repository from a spec or description. It goes deep, creating tests for happy paths, negative input validation, schema strictness, authentication/authorization, and defensive security cases.
AUDIT: Analyzes your existing test suite against your contract to find "silent killers"—untested status codes, response bodies that aren't validated against schemas, and missing edge cases that lead to production outages.

Supported Tools & Frameworks

The skill adapts to your stack, generating idiomatic code for frameworks like Jest/Supertest, Pytest/HTTPX, Playwright API, RestAssured, Vitest, and more. It focuses on REST/JSON architectures where contract drift is the primary risk.

Why use this skill?

Manual test writing often misses the boring but critical negative cases. This skill automates the creation of 4xx and 5xx test scenarios, ensures every documented schema constraint is actually checked, and identifies IDOR vulnerabilities. The output is a runnable, professional-grade test suite with a coverage matrix that maps every endpoint and status code to a specific test ID.

How to install

Drop the file into your AI Agent. Works with Claude, Cursor, ChatGPT, and 20+ more.

Reviews

No reviews yet

Be one of the first to try it. Every listed skill passes our trust checks below.

Security scanned

Passed our 8-point scan before listing

Fresh listing

Recently published to Agensi

30-day refund

Not a fit? Get your money back

API Contract Tester