# Setting up Mautrix Telegram bridging (optional)

<sup>Refer the common guide for configuring mautrix bridges: [Setting up a Generic Mautrix Bridge](configuring-playbook-bridge-mautrix-bridges.md)</sup>

The playbook can install and configure [mautrix-telegram](https://github.com/mautrix/telegram) for you.

See the project's [documentation](https://docs.mau.fi/bridges/python/telegram/index.html) to learn what it does and why it might be useful to you.

## Prerequisites

### Obtain a Telegram API key

To use the bridge, you'd need to obtain an API key from [https://my.telegram.org/apps](https://my.telegram.org/apps).

### Enable Appservice Double Puppet or Shared Secret Auth (optional)

If you want to set up [Double Puppeting](https://docs.mau.fi/bridges/general/double-puppeting.html) (hint: you most likely do) for this bridge automatically, you need to have enabled [Appservice Double Puppet](configuring-playbook-appservice-double-puppet.md) or [Shared Secret Auth](configuring-playbook-shared-secret-auth.md) service for this playbook.

See [this section](configuring-playbook-bridge-mautrix-bridges.md#set-up-double-puppeting-optional) on the [common guide for configuring mautrix bridges](configuring-playbook-bridge-mautrix-bridges.md) for details about setting up Double Puppeting.

**Notes**:

- Double puppeting with the Shared Secret Auth works at the time of writing, but is deprecated and will stop working in the future.

- If you decided to enable Double Puppeting manually, send `login-matrix` to the bot in order to receive an instruction about how to send an access token to it.

## Adjusting the playbook configuration

To enable the bridge, add the following configuration to your `inventory/host_vars/matrix.example.com/vars.yml` file. Make sure to replace `YOUR_TELEGRAM_APP_ID` and `YOUR_TELEGRAM_API_HASH`.

```yaml
matrix_mautrix_telegram_enabled: true
matrix_mautrix_telegram_api_id: YOUR_TELEGRAM_APP_ID
matrix_mautrix_telegram_api_hash: YOUR_TELEGRAM_API_HASH
```

### Relaying

If you want to use the relay-bot feature ([relay bot documentation](https://docs.mau.fi/bridges/python/telegram/relay-bot.html)), which allows anonymous user to chat with telegram users, add the following configuration to your `inventory/host_vars/matrix.example.com/vars.yml` file:

```yaml
matrix_mautrix_telegram_bot_token: YOUR_TELEGRAM_BOT_TOKEN
matrix_mautrix_telegram_configuration_extension_yaml: |
  bridge:
    permissions:
      '*': relaybot
```

You might also want to give permissions to administrate the bot:

```yaml
matrix_mautrix_telegram_configuration_extension_yaml: |
  bridge:
    permissions:
      '@alice:{{ matrix_domain }}': admin
```

More details about permissions in this example: https://github.com/mautrix/telegram/blob/master/mautrix_telegram/example-config.yaml#L410

### Use the bridge for direct chat only

If you want to exclude all groups from syncing and use the Telegram-Bridge only for direct chats, add the following configuration to your `inventory/host_vars/matrix.example.com/vars.yml` file:

```yaml
matrix_mautrix_telegram_filter_mode: whitelist
```

### Extending the configuration

There are some additional things you may wish to configure about the bridge.

<!-- NOTE: common relay mode is not supported for this bridge -->
See [this section](configuring-playbook-bridge-mautrix-bridges.md#extending-the-configuration) on the [common guide for configuring mautrix bridges](configuring-playbook-bridge-mautrix-bridges.md) for details about variables that you can customize and the bridge's default configuration, including [bridge permissions](configuring-playbook-bridge-mautrix-bridges.md#configure-bridge-permissions-optional), [encryption support](configuring-playbook-bridge-mautrix-bridges.md#enable-encryption-optional), [bot's username](configuring-playbook-bridge-mautrix-bridges.md#setting-the-bot-s-username-optional), etc.

## Installing

After configuring the playbook, run it with [playbook tags](playbook-tags.md) as below:

<!-- NOTE: let this conservative command run (instead of install-all) to make it clear that failure of the command means something is clearly broken. -->
```sh
ansible-playbook -i inventory/hosts setup.yml --tags=setup-all,ensure-matrix-users-created,start
```

**Notes**:

- The `ensure-matrix-users-created` playbook tag makes the playbook automatically create the bot's user account.

- The shortcut commands with the [`just` program](just.md) are also available: `just install-all` or `just setup-all`

  `just install-all` is useful for maintaining your setup quickly ([2x-5x faster](../CHANGELOG.md#2x-5x-performance-improvements-in-playbook-runtime) than `just setup-all`) when its components remain unchanged. If you adjust your `vars.yml` to remove other components, you'd need to run `just setup-all`, or these components will still remain installed.

## Usage

To use the bridge, you need to start a chat with `@telegrambot:example.com` (where `example.com` is your base domain, not the `matrix.` domain).

You can learn more here about authentication from the bridge's [official documentation on Authentication](https://docs.mau.fi/bridges/python/telegram/authentication.html).