Overview:
Requestly is an open-source, local-first API client that combines REST API testing, HTTP request interception, and API mocking into a single tool. It is designed as a local alternative to tools like Postman and Charles Proxy, usable either as a browser extension or a desktop application. Developers can build, test, and modify HTTP and HTTPS requests and responses directly from their browser, desktop, or mobile apps without sending data to a cloud server. The project emphasizes local storage of all API data and configurations.
Core Features:
Local & Team Workspaces: Stores all data (requests, collections, environments) in a directory on the user's disk. Supports collaboration via Git, Google Drive, or iCloud for local workspaces, or a built-in sync engine for team workspaces.
REST API Client: Provides a local interface for building and testing APIs with support for collections, environments, environment switching, and request history.
HTTP Interceptor (HTTP Rules): Intercepts, monitors, and modifies HTTP/HTTPS requests and responses from browsers, mobile apps, and other desktop applications. Supports URL redirection (Map Local/Map Remote), header and body modification, and script injection.
API Mocking: Supports creating local API mocks, static and dynamic response overrides (including GraphQL), cloud-based mock endpoints, bulk mocks from recorded traffic, and mock API usage in e2e testing pipelines (Cypress, Playwright, Selenium).
1-Click Imports: Directly import configurations and data from Postman, Charles Proxy, ModHeader, and Resource Override.
Use Cases:
Frontend developers: Mock APIs to build and test user interfaces before the backend is ready, using local mocks or recorded sessions.
Backend or QA engineers: Intercept and modify live HTTP requests and responses from browsers or mobile apps to debug and test changes without redeploying.
Developers migrating from other tools: Import existing collections, environments, or proxy rules from Postman, Charles Proxy, or ModHeader to start using Requestly immediately.
Teams using version-controlled collaboration: Use local workspaces with Git or cloud sync to share API configurations without relying on a central cloud service.
Why It Matters:
Requestly combines two common developer needs—API client and HTTP interceptor—into one local-first application. By storing all data on the user's disk, it offers a privacy-friendly workflow that works offline. Its support for local workspaces with external sync engines (Git, Google Drive) gives developers control over how they share configurations. The project also lowers the switching cost for teams coming from Postman, Charles Proxy, or ModHeader with built-in import tools, making it a practical open-source alternative in the API tooling space.
