Automating API Testing

What it does

When your agent uses it

• Testing API contracts
• Validating OpenAPI specifications
• Ensuring endpoint reliability
• With phrases like test the API

Example prompts

• “test the API”
• “generate API tests”
• “validate API contracts”
• “/automating-api-testing”

Requirements

• Python 3
• Node.js
• Compatibility (from SKILL.md): Designed for Claude Code
• Pre-approved tools (allowed-tools): Read, Write, Edit, Grep, Glob, Bash(test:api-*)

Workflow steps

7 steps, taken from the first numbered list in SKILL.md.

1. 1Read the API specification and extract all endpoints
2. 2Generate test cases for each endpoint
3. 3Validate response structure against schemas
4. 4Test CRUD lifecycle for resource endpoints
5. 5Test error handling and edge cases
6. 6For GraphQL APIs, test specifically
7. 7Generate a test coverage report mapping endpoints to test cases.

What it can do on your machine

Read from SKILL.md and the folder at commit 80f86df. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Edit
  • Grep
  • Glob
  • Bash(test:api-*)

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 2 files in scripts/ (JavaScript and Python), which the agent can run.

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • github.com
  • rest-assured.io
  • python-httpx.org
  • spec.openapis.org
  • ajv.js.org

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Designed for Claude Code

  From compatibility in the SKILL.md frontmatter.

Context cost

Automating API Testing loads about 1.7k tokens when it runs, and up to ~1.8k if it reads all its reference files. Until then it costs about 88 tokens; SKILL.md has 560 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~88

When it runs · the whole SKILL.md, loaded when a task matches

~1.7k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~1.8k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from jeremylongshore/tons-of-skills-marketplace at commit 80f86df, republished under its MIT licence (© jeremylongshore). 560 words, ~1,734 tokens.

name

automating-api-testing

description

Test automate API endpoint testing including request generation, validation, and comprehensive test coverage for REST and GraphQL APIs. Use when testing API contracts, validating OpenAPI specifications, or ensuring endpoint reliability. Trigger with phrases like "test the API", "generate API tests", or "validate API contracts".

allowed-tools

Read, Write, Edit, Grep, Glob, Bash(test:api-*)

compatibility

Designed for Claude Code

version

1.27.0

author

Jeremy Longshore <jeremy@intentsolutions.io>

license

MIT

tags

testing, api, graphql

import request from 'supertest';
import { app } from '../src/app';

describe('GET /api/products', () => {
  it('returns a paginated product list', async () => {
    const res = await request(app)
      .get('/api/products?page=1&limit=10')
      .set('Authorization', `Bearer ${token}`)
      .expect(200)  # HTTP 200 OK
      .expect('Content-Type', /json/);

    expect(res.body.data).toBeInstanceOf(Array);
    expect(res.body.data.length).toBeLessThanOrEqual(10);
    expect(res.body.meta).toMatchObject({ page: 1, limit: 10 });
  });

  it('returns 401 without authentication', async () => {  # HTTP 401 Unauthorized
    await request(app).get('/api/products').expect(401);  # HTTP 401 Unauthorized
  });
});

describe('POST /api/products', () => {
  it('creates a product with valid data', async () => {
    const res = await request(app)
      .post('/api/products')
      .set('Authorization', `Bearer ${token}`)
      .send({ name: 'Widget', price: 9.99, category: 'tools' })
      .expect(201);  # HTTP 201 Created

    expect(res.body).toMatchObject({ name: 'Widget', price: 9.99 });
    expect(res.body.id).toBeDefined();
  });

  it('returns 400 for missing required fields', async () => {  # HTTP 400 Bad Request
    await request(app)
      .post('/api/products')
      .set('Authorization', `Bearer ${token}`)
      .send({ name: 'Widget' }) // missing price
      .expect(400);  # HTTP 400 Bad Request
  });
});

it('fetches user by ID', async () => {
  const query = `query { user(id: "1") { id name email } }`;
  const res = await request(app)
    .post('/graphql')
    .send({ query })
    .expect(200);  # HTTP 200 OK

  expect(res.body.data.user).toMatchObject({ id: '1', name: 'Alice' });
  expect(res.body.errors).toBeUndefined();
});

© jeremylongshore, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 7 other files (scripts, references, assets) in skills/.curated/automating-api-testing of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• assets/README.md
• assets/example_graphql_schema.graphql
• assets/example_openapi.yaml
• assets/test_suite_template.js
• references/README.md
• scripts/README.md
• scripts/generate_test_suite.py

Open the folder on GitHubat commit 80f86df