{"product_id":"twilio-webhook-signature-verification-in-n8n-403-reject","title":"Twilio Webhook Signature Verification in n8n (403 Reject)","description":"\u003ch3\u003eVerify Twilio webhook authenticity in n8n—block forged requests with a 403\u003c\/h3\u003e\n\u003cp\u003eThis n8n workflow receives inbound \u003cstrong\u003eTwilio webhooks\u003c\/strong\u003e, verifies the \u003cstrong\u003eX-Twilio-Signature\u003c\/strong\u003e using your \u003cstrong\u003eTwilio Auth Token\u003c\/strong\u003e and the \u003cstrong\u003eexact webhook URL\u003c\/strong\u003e, and instantly \u003cstrong\u003erejects invalid requests with a 403 TwiML\u003c\/strong\u003e. Legitimate requests continue to your custom logic safely.\u003c\/p\u003e\n\n\u003ch3\u003eWhat this workflow does\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReceives a POST\u003c\/strong\u003e request from Twilio on an n8n Webhook endpoint.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLoads verification inputs\u003c\/strong\u003e: your \u003cem\u003eTwilio Auth Token\u003c\/em\u003e and the \u003cem\u003epublic webhook URL\u003c\/em\u003e (including any query string) used for signature verification.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eRecomputes the expected signature\u003c\/strong\u003e by hashing the webhook URL plus \u003cem\u003esorted POST parameters\u003c\/em\u003e using \u003cstrong\u003eHMAC-SHA1\u003c\/strong\u003e, then compares it to the incoming \u003cstrong\u003eX-Twilio-Signature\u003c\/strong\u003e header.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eValid signature path\u003c\/strong\u003e: if the signature matches, the request continues to your custom processing and returns an \u003cstrong\u003eempty TwiML response\u003c\/strong\u003e.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInvalid\/missing signature path\u003c\/strong\u003e: if the signature is invalid or absent, the workflow immediately returns \u003cstrong\u003e403\u003c\/strong\u003e with an \u003cstrong\u003eempty TwiML response\u003c\/strong\u003e to Twilio.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUse cases\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eProtect \u003cstrong\u003eTwilio Voice\u003c\/strong\u003e or \u003cstrong\u003eMessaging\u003c\/strong\u003e webhook endpoints from spoofed traffic.\u003c\/li\u003e\n  \u003cli\u003eHarden an n8n-hosted SaaS backend that handles inbound SMS\/voice events.\u003c\/li\u003e\n  \u003cli\u003eEnsure only requests signed by Twilio can trigger downstream automations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical details\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNodes\/logic used\u003c\/strong\u003e: \u003ccode\u003ewebhook\u003c\/code\u003e, \u003ccode\u003eif\u003c\/code\u003e, \u003ccode\u003eset\u003c\/code\u003e, \u003ccode\u003ecode\u003c\/code\u003e (HMAC calculation), \u003ccode\u003eno op\u003c\/code\u003e, and \u003ccode\u003esticky note\u003c\/code\u003e.\u003c\/li\u003e\n  \u003cli\u003eSet your \u003cstrong\u003eTwilio Auth Token\u003c\/strong\u003e as \u003ccode\u003eTWILIO_AUTH_TOKEN\u003c\/code\u003e (recommended) or update the placeholder in the Config step.\u003c\/li\u003e\n  \u003cli\u003eSet \u003ccode\u003eTWILIO_WEBHOOK_URL\u003c\/code\u003e to the \u003cstrong\u003eexact public HTTPS URL\u003c\/strong\u003e Twilio calls (including query string).\u003c\/li\u003e\n  \u003cli\u003eFor self-hosted n8n, ensure the Code node can access Node’s \u003cstrong\u003ecrypto\u003c\/strong\u003e module (e.g., \u003ccode\u003eNODE_FUNCTION_ALLOW_BUILTIN=crypto\u003c\/code\u003e) so HMAC-SHA1 can be computed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eResult:\u003c\/strong\u003e stronger Twilio webhook security in n8n—signature verification, safe handling, and 403 rejection for forged requests.\u003c\/p\u003e","brand":"N8N Commerce","offers":[{"title":"Default Title","offer_id":45758753374387,"sku":"N8N-17789","price":9.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0749\/6279\/6723\/files\/w0NmT6vO3pKzF6ojBSCEK_XW3N2Z95.png?v=1785834415","url":"https:\/\/buyflowscripts.com\/products\/twilio-webhook-signature-verification-in-n8n-403-reject","provider":"N8N Commerce","version":"1.0","type":"link"}