> ## Documentation Index
> Fetch the complete documentation index at: https://docs.diga.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Call Tools

> Built-in tools to control phone call flow

Call tools are built-in functions that allow your agent to perform phone actions during a conversation. Unlike HTTP or MCP integrations that connect to external services, these tools are built directly into Diga's telephony system.

## Available Tools

There are currently three call tools you can enable in your agents:

<CardGroup cols={3}>
  <Card title="Transfer" icon="https://mintcdn.com/diga/8ytXWoW-xL71V8MR/icons/phone-outgoing-01.svg?fit=max&auto=format&n=8ytXWoW-xL71V8MR&q=85&s=b09daa0026f4d3c73d31df7dd2ded713" width="24" height="24" data-path="icons/phone-outgoing-01.svg">
    Transfers the call to another phone number
  </Card>

  <Card title="Hang Up" icon="phone-off">
    Ends the call in a controlled manner
  </Card>

  <Card title="Voicemail Detection" icon="voicemail">
    Checks if the call was answered by a machine
  </Card>
</CardGroup>

<Note>
  **Conversational Path Agents**

  In agents with conversational paths, these tools are implemented through dedicated nodes within the flow.

  Learn more in [Node Types](/en/build/agents/conversational-paths/node-types).
</Note>

## Transfer Calls

The transfer tool allows the agent to redirect the call to another phone number or phone extension. This is useful for escalating conversations to human agents or specific departments.

### How it Works

When the agent executes the transfer tool:

<Steps>
  <Step title="The agent identifies the need to transfer">
    Based on the conversation context or specific conditions
  </Step>

  <Step title="The transfer is executed">
    The call is redirected to the configured phone number
  </Step>

  <Step title="The agent call ends">
    Once the transfer is made, the agent disconnects
  </Step>
</Steps>

### Configuration

To enable transfer in your agent:

1. Access your agent's configuration
2. Go to the **Call Tools** section
3. Enable the **Transfer** tool
4. Configure the tool. You can define:
   * **Destination number**: The number to which the call will be transferred.
   * **Extension**: If you use a PBX system, you can define an internal extension. If you don't specify a destination number, the extension will be made with that same number.
   * **Condition**: Explanation of when the agent should use the tool

### Common Use Cases

<AccordionGroup>
  <Accordion title="Escalation to human agents">
    When the user requests to speak with a person or the agent can't resolve the query, transfer the call to a human support team.

    **Prompt example:**

    ```markdown theme={null}
    If the user requests to speak with a person or if you can't resolve their problem,
    use the transfer tool to connect them with a human agent.
    Before transferring, explain to the user that you're going to connect them with a specialist.
    ```
  </Accordion>

  <Accordion title="Department routing">
    Route calls to different departments based on the type of query (sales, support, billing).

    **Prompt example:**

    ```markdown theme={null}
    - If the user asks about products or prices: transfer to sales department
    - If they report a technical problem: transfer to technical support
    - If they have billing questions: transfer to administration department
    ```
  </Accordion>

  <Accordion title="Conditional transfer">
    Transfer only when certain conditions are met, such as after-hours or complex cases.

    **Prompt example:**

    ```markdown theme={null}
    If we're outside business hours (before 9am or after 6pm),
    inform the user and ask if they want to be transferred to emergency services.
    ```
  </Accordion>
</AccordionGroup>

## Hang Up Calls

The hang up tool allows the agent to end the call in a controlled and natural manner when the conversation has concluded.

### How it Works

The agent can decide to end the call when:

* The conversation has fulfilled its objective
* The user indicates they don't need more help
* All user queries have been handled
* A situation is detected that requires ending the call

### Configuration

To enable the hang up function:

1. Access your agent's configuration
2. Go to the **Call Tools** section
3. Enable the **Hang Up** tool
4. Configure the **condition** to define when the agent should use the tool

### Best Practices

<Card title="Natural goodbyes" icon="handshake">
  Make sure the agent always says goodbye politely before hanging up. Include instructions in your prompt to confirm the user doesn't need anything else before ending.
</Card>

**Prompt example:**

```markdown theme={null}
Before hanging up:
1. Ask if the user needs help with anything else
2. Wait for their response
3. If they say they don't need anything else, say goodbye cordially
4. Use the hang up tool to end the call

Goodbye example:
"It's been a pleasure helping you. If you need anything else in the future, don't hesitate to call us. Have a great day!"
```

<Warning>
  **Avoid hanging up abruptly**

  Never configure the agent to hang up without first confirming with the user. This creates a poor experience and can make users feel ignored.
</Warning>

## Voicemail Detection

The voicemail detection tool identifies whether the call was answered by a machine or a real person. This is especially useful for outbound calls.

### How it Works

The system analyzes the first few seconds of audio to determine if:

* A real person answered the phone
* An answering machine or voicemail answered
* An IVR (Interactive Voice Response) system answered

### Configuration

To enable voicemail detection:

1. Access your agent's configuration
2. Go to the **Call Tools** section
3. Enable the **Voicemail Detection** tool

### Use Cases

<AccordionGroup>
  <Accordion title="Automated outbound calls">
    In outbound call campaigns, you can configure the agent to only continue the conversation if it detects a real person, or leave a recorded message if it's a voicemail.

    **Configuration example:**

    ```markdown theme={null}
    At the start of the call:
    1. Use the voicemail detection tool
    2. If you detect a real person: continue with the normal sales script
    3. If you detect a voicemail: leave a brief message and hang up

    Message for voicemail:
    "Hello, this is [Name] from [Company]. We're calling about [reason].
    Please call us at [number]. Thank you."
    ```
  </Accordion>

  <Accordion title="Campaign optimization">
    Avoid wasting agent time talking to voicemails, allowing time to be dedicated only to real conversations.
  </Accordion>
</AccordionGroup>

## Next Steps

<CardGroup cols={2}>
  <Card title="Add integrations" icon="plug" href="/en/build/agents/add-integrations">
    Connect external APIs and MCP services to your agent
  </Card>

  <Card title="Conversational paths" icon="https://mintcdn.com/diga/8ytXWoW-xL71V8MR/icons/dataflow-02.svg?fit=max&auto=format&n=8ytXWoW-xL71V8MR&q=85&s=5b2fa11c7642dae0aa1280581c82ad03" href="/en/build/agents/conversational-paths" width="24" height="24" data-path="icons/dataflow-02.svg">
    Use dedicated nodes for greater control over tools
  </Card>

  <Card title="HTTP Integrations" icon="webhook" href="/en/build/integrations/http-integrations">
    Learn how to create custom integrations
  </Card>

  <Card title="Call customization" icon="sliders" href="/en/build/agents/call-customization">
    Adjust voice, speed, and language for your agent
  </Card>
</CardGroup>