API Testing MCP

"Create a group called my-project and add this directory as scope"
"Set up a dev environment with BASE_URL http://localhost:3000"
"Switch to prod for this session"
"Set dev as the default environment"
"Import my API spec from /api-docs-json"
"Show me all user endpoints"
"GET /users"
"Create a user with random data"
"Verify that DELETE /users/5 returns 204"
"Login as admin, extract the token, then fetch dashboard stats"
"How fast is /health with 50 concurrent requests?"
"Run all my saved smoke tests"
"Compare the users endpoint between dev and prod"
"Export the create-user request as curl"
"Export my collection to Postman"

claude mcp add --scope user api-testing -- npx -y @cocaxcode/api-testing-mcp@latest

{
  "mcpServers": {
    "api-testing": {
      "command": "npx",
      "args": ["-y", "@cocaxcode/api-testing-mcp@latest"]
    }
  }
}

{
  "mcpServers": {
    "api-testing": {
      "command": "npx",
      "args": ["-y", "@cocaxcode/api-testing-mcp@latest"]
    }
  }
}

{
  "servers": {
    "api-testing": {
      "command": "npx",
      "args": ["-y", "@cocaxcode/api-testing-mcp@latest"]
    }
  }
}

codex mcp add api-testing -- npx -y @cocaxcode/api-testing-mcp@latest

[mcp_servers.api-testing]
command = "npx"
args = ["-y", "@cocaxcode/api-testing-mcp@latest"]

{
  "mcpServers": {
    "api-testing": {
      "command": "npx",
      "args": ["-y", "@cocaxcode/api-testing-mcp@latest"]
    }
  }
}

"Create an environment called dev with BASE_URL http://localhost:3000"

"Import my API spec from http://localhost:3000/api-docs-json"

"POST to /api/users with name Jane and email jane@company.com using my bearer token"

"Verify that GET /api/health returns 200, body.status is ok, and responds in under 500ms"

PASS — 3/3 assertions passed
  status === 200
  body.status === "ok"
  timing.total_ms < 500

"Login as admin@test.com, extract the access token, then use it to fetch all users"

flow_run({
  steps: [
    {
      name: "login",
      method: "POST",
      url: "/auth/login",
      body: { email: "admin@test.com", password: "SecurePass#99" },
      extract: { "TOKEN": "body.access_token" }
    },
    {
      name: "get-users",
      method: "GET",
      url: "/api/users",
      headers: { "Authorization": "Bearer {{TOKEN}}" }
    }
  ]
})

"Import my API spec from http://localhost:3000/api-docs-json"
"Import the spec from ./openapi.yaml"
"What parameters does POST /users expect?"

"Generate mock data for creating a user"

{
  "email": "user42@example.com",
  "name": "Test User 73",
  "password": "TestPass123!",
  "role": "admin"
}

"How fast is the health endpoint with 50 concurrent requests?"

LOAD TEST — GET /api/health
Requests:    50 concurrent
Successful:  50 | Failed: 0
Req/sec:     23.31

  Min: 45ms | Avg: 187ms
  p50: 156ms | p95: 412ms | p99: 523ms
  Max: 567ms

"Compare the users endpoint between dev and prod"

"Run all my saved smoke tests"

BULK TEST — 8/8 passed | 1.2s total
  health       — GET  /health      → 200 (45ms)
  list-users   — GET  /users       → 200 (123ms)
  create-post  — POST /blog        → 201 (89ms)
  login        — POST /auth/login  → 200 (156ms)

"Save this request as create-user with tags auth, smoke"
"List all requests tagged smoke"

"Create a group called my-api"
"Add this directory as scope to my-api"
"Create a dev environment with BASE_URL http://localhost:3000"   <- auto-joins group, auto-default
"Create a prod environment with BASE_URL https://api.example.com"
"List environments"                                              <- shows dev (active, default) and prod
"Switch to prod"                                                 <- session only
"Set prod as default"                                            <- persists

"Import my Postman collection from ./exported.postman_collection.json"
"Export my collection to Postman"
"Export the dev environment for Postman"

"Export my collection and dev environment"

your-project/
└── .atm/
    ├── collection.json
    └── dev.env.json

"Export the create-user request as curl"

curl -X POST \
  'https://api.example.com/users' \
  -H 'Authorization: Bearer eyJhbGci...' \
  -H 'Content-Type: application/json' \
  -d '{"name":"Jane","email":"jane@company.com"}'

~/.api-testing/
├── groups/               # Environment groups with scopes and defaults
├── environments/         # Environment variables — tokens, keys, passwords
├── collections/          # Saved requests (shareable, no secrets)
├── specs/                # Imported OpenAPI specs
└── project-envs.json     # Session-only active environments (cleared on restart)

{
  "env": { "API_TESTING_DIR": "/path/to/custom/.api-testing" }
}

src/
├── index.ts              # Entry point (shebang + StdioServerTransport)
├── server.ts             # createServer() factory
├── tools/                # 42 tool handlers (one file per category)
│   ├── request.ts        # HTTP requests (1)
│   ├── assert.ts         # Assertions (1)
│   ├── flow.ts           # Request chaining (1)
│   ├── collection.ts     # Collection CRUD (4)
│   ├── environment.ts    # Environment management (8)
│   ├── group.ts          # Environment groups (7)
│   ├── api-spec.ts       # OpenAPI import/browse (4)
│   ├── mock.ts           # Mock data generation (1)
│   ├── load-test.ts      # Load testing (1)
│   └── utilities.ts      # curl, diff, bulk, import/export (12)
├── lib/                  # Business logic (no MCP dependency)
│   ├── http-client.ts    # fetch wrapper with timing
│   ├── storage.ts        # JSON file storage engine
│   ├── schemas.ts        # Shared Zod schemas
│   ├── url.ts            # BASE_URL resolution
│   ├── path.ts           # Dot-notation accessor (body.data.0.id)
│   ├── interpolation.ts  # {{variable}} resolver
│   └── openapi-parser.ts # $ref + allOf/oneOf/anyOf resolution
└── __tests__/            # 10+ test suites, 120+ tests