API Development Tool
6.6k 2026-04-22
requestly/requestly
A free and open-source API client and HTTP interceptor that streamlines API testing, mocking, and modification for developers.
Core Features
Local-first REST API Client with collections and environments
Powerful HTTP Interceptor to monitor and modify requests/responses
API Mocking for rapid frontend development without backend dependency
Support for URL redirects, header/body modifications, and script injection
Seamless collaboration via local or team workspaces
Detailed Introduction
Requestly is a versatile, open-source developer tool that integrates the functionalities of an API client (like Postman) and an HTTP interceptor (like Charles Proxy). It empowers developers to build, test, and mock APIs efficiently, offering features such as local-first workspaces, environment management, and comprehensive HTTP request/response modification. Available as a browser extension or desktop app, Requestly accelerates frontend development by enabling API mocking and facilitates debugging by allowing real-time traffic interception and alteration.