SFV Interceptor

Mock REST and GraphQL responses, replace JS and CSS files, and inject page code.

SFV Interceptor helps you develop and test websites with configurable request, response, and page-resource rules. • Replace REST and GraphQL responses with your own content, status codes, headers, and delays. • Modify requests and responses with JavaScript. • Replace JavaScript and CSS files, and run page code on matching URLs. • Create, edit, version, search, and export local rules. Import JSON from a file or an HTTPS URL. • Subscribe to rule URLs for automatic updates. The source maintains rule content and versions; you can turn each rule on or off. • Manage rules in the dashboard and use the popup to search, switch rules on or off, and see which rules ran on the current page. Rule matching and request, response, and resource processing happen in your browser. Rules and preferences are stored locally. There are no accounts, analytics, or developer-operated data collection servers. Subscriptions check the URLs you add, and file transformations can retrieve the original website resources. The extension starts with an empty rule list. Choose your rules, sources, and activation settings in the dashboard, and manage website access through Chrome's extension settings. Source code, support, and the privacy policy are available in the project repository.