api-testing
REST and GraphQL testing, Postman/Insomnia patterns, contract testing, schema validation, and monitoring
Profile →npx skills add cosmicstack-labs/mercury-agent-skills --skill api-testing --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# API Testing Test REST and GraphQL APIs systematically. ## Test Categories | Category | What | Example | |----------|------|---------| | Functional | Does it work? | POST /users returns 201 | | Validation | Input handling | Missing required field → 400 | | Auth | Access control | No token → 401 | | Edge Cases | Boundary conditions | Max page size, empty results | | Contract | Schema conformance | Response matches OpenAPI spec | | Performance | Within SLO | p95 < 500ms | ## REST API Testing ### Structure ```typescript describe('POST /users', () => { it('creates a user with valid data', async () => { const res = await request(app) .post('/api/users') .send({ name: 'Alice', email: 'alice@test.com' }); expect(res.status).toBe(201); expect(res.body).toHaveProperty('id'); }); it('rejects duplicate email', async () => { const res = await request(app) .post('/api/users') .send({ name: 'Alice', email: 'existing@test.com' }); expect(res.status).toBe(409); }); }); ``` ## Contract Testing (Pact) - Provider publishes OpenAPI spec - Consumer tests verify against published spec - CI rejects PR if contract breaks - Prevents API drift between services ## GraphQL Testing - Test queries and mutation
- Test Categories
- REST API Testing
- Structure
- Contract Testing (Pact)
- GraphQL Testing
- API Monitoring
What does the api-testing skill do?
REST and GraphQL testing, Postman/Insomnia patterns, contract testing, schema validation, and monitoring
How do I install it?
Run `npx skills add cosmicstack-labs/mercury-agent-skills --skill api-testing --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From cosmicstack-labs/mercury-agent-skills, a repository with 364 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.