Mockoon

Mockoon is a powerful tool for designing and running mock REST APIs. It's designed to be easy to use and quick to set up, making it ideal for developers who need to simulate API behavior during development and testing.

Key features include:

• Local mocking: Run mock APIs locally without requiring remote deployments or accounts.
• Cross-platform compatibility: Works on Windows, macOS, and Linux.
• Open-source and free: No licensing costs or hidden fees.
• Customizable mock APIs: Create realistic mock APIs with dynamic templating, rules matching, and JSON databases.
• Integration with existing workflows: Compatible with the OpenAPI specification.
• Advanced features: HTTP requests recording, proxying, and integration testing.
• Self-hosting: Use the CLI and Docker image to run mock APIs on servers and headless environments.
• Serverless deployment: Deploy mock APIs in cloud functions (AWS Lambda, GCP Functions, etc.).
• Privacy-focused: Offline-first design requires no account creation.

Use cases:

• Frontend development without a backend.
• Integration testing.
• Simulating API behavior for documentation.
• Testing edge cases and error handling.
• API UX research.