requestlyFree and open-source API Client & Interceptor.

requestly

Requestly is a free, open-source API client and HTTP interceptor that combines the functionality of tools like Postman and Charles Proxy in a single local-first application. It enables developers to build, test, mock, and intercept APIs directly from their browser or desktop with full control over requests and responses.

Key Features

• REST API Client: Build and test APIs with collections, environments, and request history in a local playground
• HTTP Interceptor: Intercept, monitor, and modify HTTPS requests and responses from browsers and mobile apps
• API Mocking: Create local and cloud-based API mocks, override responses dynamically, and support GraphQL
• Local Workspaces: Store all data locally on your disk with Git, Google Drive, or iCloud sync options
• 1-Click Imports: Migrate configurations directly from Postman, Insomnia, Charles Proxy, ModHeader, and other tools

Use Cases

• Frontend Development: Mock APIs and accelerate development without waiting for backend services to be ready
• API Testing: Intercept and modify requests to test edge cases and error scenarios in real-time
• Environment Management: Switch between development, staging, and production environments seamlessly
• Traffic Debugging: Capture and analyze HTTP traffic from web and mobile applications
• End-to-End Testing: Mock APIs in Cypress, Playwright, and Selenium tests within CI pipelines

Who Is It For

Requestly is designed for developers, QA engineers, and API teams who need a privacy-conscious, self-hosted alternative to commercial tools. It's ideal for those who prefer local-first solutions with the flexibility to collaborate using their preferred version control or sync systems.