Send TTS Voice Calls and Email Verification with ClickSend

Overview

This workflow automates a dual verification process: it sends a Text-to-Speech (TTS) voice call to a user's phone number and simultaneously sends a verification code via email. The user is then prompted to enter the codes received through both channels to confirm their identity. This is ideal for secure user onboarding, password resets, or any scenario where multi-factor verification is required.

By combining voice call delivery with email verification, this workflow provides an extra layer of security and accessibility — users who may not have immediate access to email can still verify via a phone call, and vice versa.

Workflow Steps

Below is the complete list of nodes in the workflow, with their types and authentication methods:

1. On form submission (Form Trigger) — No auth. This node starts the workflow when a user submits an n8n form. The form collects: phone number (To), voice type (Voice), language (Lang), email address (Email), and name (Nome).
2. Set voice code (Set) — No auth. This node sets a hardcoded verification code (12345) that will be spoken in the voice call.
3. Code for voice (Code) — No auth. This JavaScript node takes the code from the previous step and inserts spaces between each character (e.g., 12345 becomes 1 2 3 4 5) so the TTS voice reads each digit individually.
4. Send Voice (HTTP Request) — Basic Auth (username/password). This node sends a POST request to the ClickSend Voice API endpoint. The request body includes the spaced code, the recipient's phone number, voice type, and language. Authentication uses the credentials stored in n8n (generic HTTP Basic Auth).
5. Verify voice code (Form) — No auth. This node presents a web form asking the user to enter the verification code they heard on the phone call.
6. Is voice code correct? (IF) — No auth. This node compares the user's input from the form with the originally set code (12345). If they match, the workflow proceeds to the success path; otherwise, it goes to the failure path.
7. Fail voice code (Form) — No auth. This node displays a completion form saying the voice code was invalid.
8. Set email code (Set) — No auth. This node sets a different hardcoded code (56789) for email verification.
9. Send Email (Email Send) — SMTP credentials (configured in n8n). This node sends an email to the user's address with the subject "Verify your code" and an HTML body containing the email verification code.
10. Verify email code (Form) — No auth. This node presents a second web form asking the user to enter the code received in the email.
11. Is email code correct? (IF) — No auth. This node compares the user's email input with the set code (56789). If correct, the workflow proceeds to the success node; otherwise, it goes to the failure path.
12. Success (Form) — No auth. This node displays a completion form confirming that both the phone number and email have been verified successfully.
13. Fail email code (Form) — No auth. This node displays a completion form saying the email code was invalid.

Setup Instructions

To use this workflow, you will need:

• ClickSend account: Register at ClickSend and obtain your API Key. You will receive €2 of free credits to test the voice calls.
• SMTP credentials: For sending emails, you need an SMTP server (e.g., Gmail, SendGrid, or your own mail server). Configure the SMTP credentials in n8n under "Credentials" > "Email Send (SMTP)".
• n8n instance: This workflow runs on n8n (self-hosted or cloud). Ensure you have the HTTP Request node, Form Trigger node, and Form nodes available.

Steps to configure:

1. In the Send Voice node, set the authentication to "Basic Auth" and enter your ClickSend username (the registered email) and API Key as the password. The URL is already set to {{ $env.WEBHOOK_URL }} — you can replace this with the actual ClickSend Voice API endpoint: https://api.clicksend.com/v3/voice/send.
2. In the Send Email node, configure the From Email field with your verified sender address and ensure your SMTP credentials are set in n8n.
3. Optionally, update the hardcoded verification codes in the Set voice code and Set email code nodes to generate random codes (e.g., using a Code node or n8n's built-in functions).
4. Publish the workflow and share the form URL (from the On form submission trigger) with your users.

Use Cases and Variations

• User onboarding: Automate the verification of new users' phone numbers and email addresses during sign-up.
• Password reset: Send a temporary code via voice call and email to confirm identity before allowing password changes.
• Two-factor authentication (2FA): Use this as a simple 2FA mechanism for sensitive actions.
• Customization: Replace the hardcoded codes with dynamically generated random numbers using a Code node. You can also add a database lookup to store verification attempts.
• Alternative services: Replace ClickSend with any TTS API (e.g., Twilio, Nexmo) by modifying the HTTP Request node's URL, method, and body.

{
  "id": "1g8EAij2RwhNN70t",
  "meta": {
    "instanceId": "workflow-d3b682e5",
    "versionId": "1.0.0",
    "createdAt": "2025-09-29T07:07:42.383575",
    "updatedAt": "2025-09-29T07:07:42.383864",
    "owner": "n8n-user",
    "license": "MIT",
    "category": "automation",
    "status": "active",
    "priority": "high",
    "environment": "production"
  },
  "name": "xSend and check TTS (Text-to-speech) voice calls end email verification",
  "tags": [
    "automation",
    "n8n",
    "production-ready",
    "excellent",
    "optimized"
  ],
  "nodes": [
    {
      "id": "56842e20-266b-4770-b4cd-3106418caefa",
      "name": "Sticky Note",
      "type": "n8n-nodes-base.stickyNote",
      "position": [
        -480,
        -740
      ],
      "parameters": {
        "width": 440,
        "height": 180,
        "content": "## STEP 1\n[Register here to ClickSend]({{ $env.WEBHOOK_URL }} and obtain your API Key and 2 € of free credits\n\nIn the node \"Send Voice\" create a \"Basic Auth\" with the username you registered and the API Key provided as your password"
      },
      "typeVersion": 1,
      "notes": "This stickyNote node performs automated tasks as part of the workflow."
    },
    {
      "id": "9dfff5ae-fc04-4957-a7b6-6866e8ab0854",
      "name": "Sticky Note1",
      "type": "n8n-nodes-base.stickyNote",
      "position": [
        -480,
        -320
      ],
      "parameters": {
        "width": 440,
        "content": "## STEP 3\n\nSubmit the form and you will receive a call to the phone number you entered where the selected voice will tell you the content of the text you wrote."
// ... truncated (copy to see full JSON)