tamper Node.js middleware to capture and modify response bodies Installation npm install tamper Usage var tamper = require('tamper'); app.use(tamper(function(req, res) { // Look at the request or the response headers and decide what to do. // In this case we only want to modify html responses: if (res.getHeader('Content-Type') != 'text/html') { // When returning a falsy value processing will continue as usual // without any performance impact. return; } // Return a function in order to capture and modify the response body: return function(body) { // The function may either return a Promise or a string return body.replace(/foo/g, 'bar'); }; }); License MIT