# Connect an AI voice application

Connect a SIP-capable conversational application to Bird Voice. Bird carries the telephone connection. Your application manages speech, model behavior, business tools and the response to the caller.

## Prepare the conversation

Choose the task the assistant should complete and the conditions that require a person. For a booking assistant, distinguish checking availability from changing a booking. Confirm the customer’s intended action before asking the booking system to perform it.

Define how the application responds when a tool times out or returns an uncertain result. Check the existing operation before retrying a change that might already have succeeded.

## Configure the telephone connection

Create a [SIP trunk](/docs/guides/voice/sip-trunks) for the application. New trunks have inbound and outbound calling disabled. Configure the authentication, supported transport and media settings in the runtime that connects to it.

For incoming calls, select **Enable inbound** on the trunk, configure a delivery gateway and point an eligible [Voice number](/docs/guides/voice/receiving-calls) at the trunk. Test that the application answers and hears the caller.

For outgoing calls, select **Enable outbound** on the trunk, then prepare an eligible caller identity and enable the intended destination. Apply the calling limits and permissions appropriate to the use case. Verify audio in both directions before increasing traffic.

## Connect the business action

Give the conversational application access to only the tools and customer context it needs. Use the business system’s result to decide what the assistant says next.

For example, the assistant can offer an available Friday appointment. After the caller agrees, the application submits the change. The assistant confirms the appointment only after the booking system confirms it.

## Test the conversation under interruption

Exercise the actual telephone audio path. A transcript-only test does not establish that speech timing, interruption handling or audio quality works on a call.

Test a caller who interrupts, changes their mind, gives an ambiguous date or asks for an unsupported action. Test unavailable tools and slow responses. The application should explain the next useful step without claiming an action succeeded when its result is unknown.

## Prepare human handoff

Route the caller to the person or system responsible for the next step. Carry the customer’s request and the last confirmed action into that handoff.

Confirm that the receiving route is available before relying on it. Prepare a callback or other useful response for an unavailable destination. Keep any new call leg connected to the interaction when reviewing its outcome.

## Observe the outcome

Use [call records](/docs/guides/voice/call-log) and [Voice events](/docs/guides/voice/events) for telephone status. Join the call or session to the booking, case or other business record for task completion.

Bird’s hosted MCP tools manage supported workspace operations. They are separate from the live speech and reasoning loop in an AI voice runtime.

## Next steps

- [SIP trunks](/docs/guides/voice/sip-trunks)
- [Receiving calls](/docs/guides/voice/receiving-calls)
- [Recordings and transcripts](/docs/guides/voice/recordings)

## Related resources

- [Setting up your coding agent](/learn/basics/setting-up-your-coding-agent) (video)
- [What is an MCP server, and how does an agent use one to send messages?](/explained/platform/what-is-an-mcp-server-and-how-does-an-agent-send-messages) (answer)
- [Coding agents](/ai) (product)
- [Build with AI agents](/learn/paths/agents) (course)

[Get an implementation brief](/learn/workspace?topic=agents)