FlowCraft is a free, open-source Chrome extension designed for developers looking to manipulate HTTP requests and responses effectively. This versatile tool allows users to mock APIs, modify headers, and inject scripts, all while prioritizing user privacy. With features like response mocking, URL redirection, and request blocking, developers can test applications against various scenarios without needing backend changes. It is particularly useful for frontend and backend developers, QA engineers, and security researchers who require precise control over HTTP-level interactions.

With a commitment to privacy, FlowCraft processes all data locally, ensuring no telemetry or tracking occurs. The extension supports a wide range of use cases such as debugging CORS issues, testing error handling, and blocking unwanted requests. Built using modern web technologies, it offers a robust and user-friendly interface, making it an essential tool for developers seeking to enhance their workflow while maintaining data security.