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Your AI Voice Agent can dynamically trigger external REST APIs and webhooks (such as n8n, Make.com, Zapier, custom CRMs, internal databases, or booking engines) in the middle of live phone calls. The agent extracts spoken parameters from the conversation (e.g., date, time, customer name, order number), makes the HTTP request in real time, and speaks the returned result back to the caller naturally.

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1. How Dynamic Tool Calling Works

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2. Adding a Custom Tool to Your Agent

To configure a custom tool for your AI Agent:
  1. Open your agent from the dashboard.
  2. In the configuration panel, click the Custom Tools tab.
  3. Click Add Custom Tool in the top right.
  4. Fill in the tool configuration fields:

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Configuration Fields

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3. Configuring Custom Headers & Authentication

If your API requires an API key, Bearer token, or custom headers:
  1. Under the Headers section, click + Add Header.
  2. Enter the key and value:
Headers are securely stored and sent directly by your backend server on every request. They are never exposed to the caller.

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4. Configuring Tool Parameters

Parameters define the data that the AI will extract from the caller’s spoken words or pass as fixed default values:
  1. Under the Parameters section, click + Add Parameter.
  2. Configure each parameter:
    • Name: The JSON key (e.g. date, time, order_id, customer_name).
    • Type: string, number, integer, or boolean.
    • Description: Guidance for the AI (e.g. Date in YYYY-MM-DD format (e.g. 2026-08-21)).
    • Required: Check if the tool cannot execute without this parameter.

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Passing Hardcoded or Default Values

If you want the AI to always pass a fixed value (such as a company ID or fixed phone number) without asking the caller:
  • In the Description, write: Always pass "+919019068738" or Fixed user ID. Always pass "USR_12345".
  • The AI will automatically include that exact value in the payload without asking the customer.

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5. Testing Your Tool in the Dashboard

Before placing a live call, you can test your tool directly from the dashboard:
  1. On the tool card, click the Test (▶️) button.
  2. Enter sample test parameter values in the modal.
  3. Click Run Test.
  4. The modal will display the exact HTTP status (HTTP 200 SUCCESS, 401, 500) and the returned JSON data.

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6. Instructing Your AI Agent in the System Prompt

While Gemini will automatically detect tools based on their description, mentioning them in your System Prompt & Rules ensures strict, deterministic workflow execution:

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7. Connecting to n8n Webhooks

You can trigger any n8n workflow live during a call:
  1. In n8n, create a Webhook node with method POST.
  2. Copy the Production Webhook URL (e.g., https://your-n8n.app/webhook/voice-lead).
  3. In Trikon Voice Custom Tools, add a new tool:
    • Method: POST
    • URL: Your n8n webhook URL
    • Parameters: customer_name, intent, phone_number
  4. When the caller speaks, n8n receives the live payload instantly and continues your automation flow (sending WhatsApp messages, updating Google Sheets, notifying Slack, etc.).