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

# Outbound calls

> Configure a SIP application to place calls through a Spectrum iMessage line.

Outbound calling connects your SIP application to an iMessage line owned by
your Spectrum project.

<Note>
  Business profile registration is recommended for production, but it is not
  required. Outbound calls work without any business profile registration,
  although they may be flagged.
</Note>

## Before you start

You need:

* A Spectrum project.
* An iMessage line in that project.
* The project's ID and secret.
* A SIP client, PBX, or voice application that supports TCP transport.

WhatsApp numbers cannot be used for Spectrum Voice.

## Set up outbound calling

<Steps>
  <Step title="Find your project credentials">
    Sign in to the [Spectrum dashboard](https://app.photon.codes), select the
    project that owns your iMessage line, and open its settings.

    Copy the **project ID** and **project secret**. You will use them as SIP
    credentials:

    * Project ID → SIP username
    * Project secret → SIP password

    Use the project ID, not the project's display name.
  </Step>

  <Step title="Add a SIP account or trunk">
    In your SIP application, create an account or trunk with these exact
    values:

    | SIP setting   | Value                        |
    | ------------- | ---------------------------- |
    | Server or URI | `sip.spectrum.photon.codes`  |
    | Username      | Your Spectrum project ID     |
    | Password      | Your Spectrum project secret |
    | Transport     | `TCP`                        |

    SIP products name these fields differently. The server field might be
    called **SIP URI**, **domain**, **registrar**, **proxy**, or **host**. In
    each case, use `sip.spectrum.photon.codes`.
  </Step>

  <Step title="Force TCP transport">
    Select TCP explicitly. Do not leave transport on an automatic setting if
    your SIP application might choose UDP or TLS.

    Spectrum Voice currently supports only SIP over TCP. A `sips:` URI will
    not work.
  </Step>

  <Step title="Connect and authenticate">
    Start the SIP application and confirm that it connects successfully.

    If authentication fails, check that the project ID and project secret are
    from the same project and do not contain extra spaces or line breaks.
  </Step>

  <Step title="Place a test call">
    Place a call through the configured SIP account. Confirm that the call uses
    an iMessage line owned by the authenticated project.

    Test call setup and two-way audio before using the connection in
    production.
  </Step>
</Steps>

## Example configuration

These environment variable names are examples for your own application. They
are not read automatically by `spectrum-ts`.

```bash theme={null}
SPECTRUM_SIP_URI=sip.spectrum.photon.codes
SPECTRUM_SIP_USERNAME=your-project-id
SPECTRUM_SIP_PASSWORD=your-project-secret
SPECTRUM_SIP_TRANSPORT=tcp
```

Keep the project secret in a secret manager or protected environment variable.
Do not commit it to source control or send it to browser code.

## Optional: register your business profile

Outbound calling works without a registered business profile. Registration is
still recommended because calls from an unregistered business may be flagged.

To register:

<Steps>
  <Step title="Open the business profile">
    In the dashboard, select the project that places the calls and open its
    business profile.
  </Step>

  <Step title="Submit the business information">
    Complete the requested business details and submit the profile. There is no
    registration fee.
  </Step>

  <Step title="Wait for registration to finish">
    Registration usually takes 1–2 business days. You can continue developing
    and making outbound calls while it is being processed.
  </Step>
</Steps>

Registration reduces the risk associated with unidentified outbound traffic,
but it should not be treated as a guarantee that a call will never be flagged.

## Before going live

* The iMessage line belongs to the same project as the SIP credentials.
* The server is exactly `sip.spectrum.photon.codes`.
* The username is the project ID, not the project name.
* The password is the current project secret.
* The transport is TCP, not UDP or TLS.
* A test call connects and has working two-way audio.
* The business profile has been submitted if you want to reduce flagging risk.

## Troubleshooting

### The SIP application cannot connect

Check the server spelling and force the transport to TCP. Disable automatic
UDP or TLS selection. Also confirm that your network allows the SIP application
to make an outbound TCP connection.

### Authentication fails

Use the project ID as the username and the project secret as the password. Make
sure both came from the same project. If the secret was rotated, replace the
old value in the SIP application.

### The line is not available

Confirm that the project owns an iMessage line. WhatsApp and voice-only lines
are not currently supported for Spectrum Voice.

### Calls are flagged

Outbound calls can work without a registered business profile, but they may be
flagged. Register the business profile in the dashboard and allow 1–2 business
days for registration to complete.