Api Mock Server

What it does

This skill enables AI agents to create realistic mock APIs for testing and development purposes. It supports three different approaches: MSW, json-server, or custom implementations. The agent can define endpoint handlers, set up test data (fixtures), configure success/error scenarios, integrate these mocks into test suites, and document the API contract created by the mock.

When to use it

• When you need to test an application against an API that is not yet available or stable.
• For development purposes when simulating backend behavior without relying on a live server.
• To create isolated testing environments for specific features or components.
• When needing to control the responses from an API to reproduce edge cases or error conditions.

Key capabilities

• Supports three mocking approaches: MSW, json-server, and custom implementations.
• Allows defining mock endpoint handlers with configurable success and error states.
• Enables setting up test data (fixtures) for realistic simulations.
• Provides the ability to integrate mocks into existing test suites.
• Facilitates documenting API contracts based on the created mocks.

Example prompts

• "Create a mock API endpoint using MSW that returns a list of users."
• "Simulate a POST request to /api/users with a 201 status code and return the newly created user data."
• "Generate test data for a GET request to /api/users/:id, where id is '1'."

Tips & gotchas

• The skill supports MSW, which requires initial setup (npm install -D msw and npx msw init ./public --save).
• You will need to define handlers (e.g., in a mocks/handlers.ts file) to specify the behavior of each mock endpoint.
• The skill allows for delays using await delay(100) within handler definitions, simulating network latency.