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

# SIP Registration

> Register a Vida Agent to an external PBX or SIP service for supported inbound, outbound, and transfer workflows.

SIP registration lets a Vida Agent connect to an external PBX or SIP service like a VoIP endpoint.
Use credentials created specifically for the Agent and confirm the expected calling permissions with
your telephony provider.

## Required settings

* **SIP domain:** Provider or PBX domain, such as `sip.example.com`.
* **Username:** Registration user or extension.
* **Password:** Registration password.

Optional settings can include:

* **Proxy:** Separate SIP proxy or outbound server.
* **Port:** SIP signaling port. The default is normally `5060`.
* **Transport:** `UDP` or `TCP` as required by the provider.
* **Subscribe to presence:** Enable only when the provider supports the presence subscription the
  workflow needs.

Keep registration passwords in the SIP credential setting. Do not put them in Agent instructions,
Tasks, or support screenshots.

## Configure and verify

1. Confirm the selected Agent account.
2. Check whether the intended address of record is available.
3. Save the registration settings.
4. Read the registration and review its current status.
5. Place representative inbound and outbound calls.
6. Test internal extension transfer when the workflow uses it.
7. Inspect both Vida logs and the provider's SIP evidence.

A successful registration status proves the PBX accepted the registration; it does not prove every
call route, caller identity, codec, or transfer path works.

## Transfer to PBX destinations

The [Call Transfer](/docs/functions/call-transfer) function can use a configured registration for
supported internal destinations. For example, an Agent instruction may direct an approved sales
transfer to `ext:1002` or another destination format supported by the registration.

Test each destination and fallback behavior before production use.

<Note>
  Configuring registration programmatically? Use the generated operations for
  [reading](/docs/api-reference/sip/get-sip-registration),
  [creating or updating](/docs/api-reference/sip/create-or-update-sip-registration), and
  [deleting](/docs/api-reference/sip/delete-sip-registration) a registration.
</Note>