1.4Pre-Request Scripts

Pre-request scripts run before the request is sent — useful for generating dynamic data or calculating signatures.

// Generate a unique email for each test run
const timestamp = Date.now();
pm.environment.set("test_email", `testuser_${timestamp}@test.com`);

// Calculate HMAC signature for signed requests
const CryptoJS = require('crypto-js');
const secret = pm.environment.get("api_secret");
const payload = JSON.stringify(pm.request.body.raw);
const signature = CryptoJS.HmacSHA256(payload, secret).toString();
pm.request.headers.add({ key: "X-Signature", value: signature });