XApi HTTP Client - API Tool, Modify Header & Response

Intercept, debug, modify header & response, replay HTTP requests. Comprehensive API client & cURL support in Chrome DevTools.

Stop switching context between your browser and external API clients like Postman or Insomnia. XApi HTTP Client brings a full-featured API testing environment directly into your Chrome DevTools panel. Built with the latest Manifest V3 technology, this extension allows you to intercept, inspect, edit, and replay HTTP requests without ever leaving your current tab. It provides advanced capabilities including support for modifying restricted request headers such as Origin, Referer, and User-Agent, giving you complete control over your API testing scenarios. XApi HTTP Client is lightweight, secure, and designed specifically for frontend developers and QA engineers who need a seamless debugging experience directly in their browser environment. KEY FEATURES 1. Seamless DevTools Integration Access the "HTTP Tool" tab directly in your F12 Developer Tools. Debug APIs in the exact context of your web application. 2. Intercept & Record Traffic Automatically capture live Fetch and XHR requests occurring on the page. View status codes, timing, size, and methods (GET, POST, PUT, DELETE, PATCH, etc.) in real-time. 3. Edit & Replay Requests Found a bug? Don't just watch it happen—fix it. Click any captured request to open it in the editor. Modify: Query Parameters: Add, remove, or disable params. Headers: Tweak authorization tokens or content types. Request Body: Full support for JSON, Raw Text, x-www-form-urlencoded, and Multipart Form-Data (including file uploads). History: Access your recently captured requests instantly. 4. cURL Import Have a cURL command from your backend team or server logs? simply paste it into the importer, and we'll convert it into an editable request instantly. 5.Mock & Response Override Intercept live requests and serve custom responses without touching the backend — ideal for front-end development, edge-case testing, and reproducing bugs. PRIVACY & SECURITY Offline First: We do not track your usage or collect your API data. Local Execution: All requests originate from your browser, ensuring access to local/intranet APIs (localhost) works perfectly. Open Source: Transparent code for peace of mind. Why install HTTP CaptureExt Client? If you are tired of copying authentication tokens from the browser to an external tool, or if you need to quickly test how your backend handles different payloads without writing code, this is the tool for you. Update Log (v1.1.1): Fix the issue where newly added request parameters fail to load into params. Support Chinese and English multilingual. Update Log (v2.1.0): 1.Fix the issue with submitting data via Form Data 2.Auto transcode imported cURL requests of the x-www-form-urlencoded type Update Log (v3.1.1): 1.Supports collapsing and expanding JSON response content 2.Allows modification of response data 3.Optimizes lag issues with large JSON responses Update Log (v3.1.3): 1.Resolve the issue where the MOCK feature fails to work 2.Optimize text copy and UI styles Update Log (v3.1.3): 1.Bug fix 2.Optimize styles Update Log (v3.1.7): 1.Support Modify Header 2.Optimize styles