Add docs and CHANGELOG entry for Matrix <-> Meshtastic bridge

Co-authored-by: luschmar <90399580+luschmar@users.noreply.github.com>

CHANGELOG.md

@@ -1,5 +1,11 @@
 # 2026-04-24
 
+## Support for bridging to Meshtastic via meshtastic-matrix-relay
+
+Thanks to [luschmar](https://github.com/luschmar), the playbook now supports bridging to [Meshtastic](https://meshtastic.org/) mesh networks via [meshtastic-matrix-relay](https://github.com/jeremiah-k/meshtastic-matrix-relay) (mmrelay).
+
+To learn more, see our [Setting up a Matrix <-> Meshtastic bridge](./docs/configuring-playbook-bridge-meshtastic-relay.md) documentation page.
+
 ## (BC Break) mautrix-telegram has been rewritten in Go (bridgev2)
 
 The [mautrix-telegram](./docs/configuring-playbook-bridge-mautrix-telegram.md) bridge has been [rewritten in Go](https://mau.fi/blog/2026-04-mautrix-release/) on top of the [bridgev2](https://docs.mau.fi/bridges/go/) architecture. See the [upstream v26.04 release notes](https://github.com/mautrix/telegram/releases/tag/v0.2604.0) for what changed in the bridge itself (shared-portal behavior, management-room state, new features, etc.).

README.md

@@ -132,6 +132,7 @@ Bridges can be used to connect your Matrix installation with third-party communi
 | [matrix-steam-bridge](https://github.com/jasonlaguidice/matrix-steam-bridge) | ❌ | Bridge to [Steam](https://steampowered.com/) | [Link](docs/configuring-playbook-bridge-steam.md) |
 | [matrix-wechat](https://github.com/duo/matrix-wechat) | ❌ | Bridge to [WeChat](https://www.wechat.com/) | [Link](docs/configuring-playbook-bridge-wechat.md) |
 | [Heisenbridge](https://github.com/hifi/heisenbridge) | ❌ | Bouncer-style bridge to [IRC](https://wikipedia.org/wiki/Internet_Relay_Chat) | [Link](docs/configuring-playbook-bridge-heisenbridge.md) |
+| [meshtastic-matrix-relay](https://github.com/jeremiah-k/meshtastic-matrix-relay) | ❌ | Bridge to [Meshtastic](https://meshtastic.org/) mesh networks | [Link](docs/configuring-playbook-bridge-meshtastic-relay.md) |
 | [mx-puppet-groupme](https://gitlab.com/xangelix-pub/matrix/mx-puppet-groupme) | ❌ | Bridge to [GroupMe](https://groupme.com/) | [Link](docs/configuring-playbook-bridge-mx-puppet-groupme.md) |
 | [mx-puppet-steam](https://codeberg.org/icewind/mx-puppet-steam) | ❌ | Bridge to [Steam](https://steamapp.com/) | [Link](docs/configuring-playbook-bridge-mx-puppet-steam.md) |
 | [Postmoogle](https://github.com/etkecc/postmoogle) | ❌ | Email to Matrix bridge | [Link](docs/configuring-playbook-bridge-postmoogle.md) |

docs/configuring-playbook-bridge-meshtastic-relay.md

@@ -0,0 +1,95 @@
+<!--
+SPDX-FileCopyrightText: 2025 - 2026 luschmar
+SPDX-FileCopyrightText: 2026 Slavi Pantaleev
+
+SPDX-License-Identifier: AGPL-3.0-or-later
+-->
+
+# Setting up a Matrix <-> Meshtastic bridge (optional)
+
+The playbook can install and configure [meshtastic-matrix-relay](https://github.com/jeremiah-k/meshtastic-matrix-relay) (sometimes referred to as `mmrelay`) for you — a bridge between [Matrix](https://matrix.org/) and [Meshtastic](https://meshtastic.org/) mesh networks.
+
+See the [project's documentation](https://github.com/jeremiah-k/meshtastic-matrix-relay) to learn what it does and why it might be useful to you.
+
+## Prerequisites
+
+You need a Matrix account for the bot. You can either [register the bot account manually](registering-users.md) or let the playbook create it when running `ansible-playbook … --tags=ensure-matrix-users-created`. Either way, you'll need the account's **password** to configure the bridge — unlike most other bridges in this playbook, `mmrelay` authenticates with a password and creates its own session (optionally with End-to-End Encryption material).
+
+You also need access to a Meshtastic device, connected to the server via one of:
+
+- **TCP**: the device is reachable on the network (e.g. a Meshtastic node running the TCP API),
+- **Serial**: the device is plugged in via USB and available on the host (e.g. `/dev/ttyUSB0`),
+- **BLE**: the device is reachable via Bluetooth Low Energy from the host.
+
+## Adjusting the playbook configuration
+
+To enable the bridge, add the following configuration to your `inventory/host_vars/matrix.example.com/vars.yml` file:
+
+```yaml
+matrix_meshtastic_relay_enabled: true
+
+# Password for the bot's Matrix account.
+# On first startup, the bridge uses this to log in and persist credentials
+# (including End-to-End Encryption material) under its data directory.
+# After that, the password can be removed from this variable.
+matrix_meshtastic_relay_matrix_bot_password: "PASSWORD_FOR_THE_BOT"
+
+# How the bridge connects to your Meshtastic device.
+# One of: tcp, serial, ble
+matrix_meshtastic_relay_connection_type: tcp
+
+# For connection_type: tcp
+matrix_meshtastic_relay_tcp_host: "meshtastic.local"
+
+# For connection_type: serial
+# matrix_meshtastic_relay_serial_port: "/dev/ttyUSB0"
+
+# For connection_type: ble
+# matrix_meshtastic_relay_ble_address: "AA:BB:CC:DD:EE:FF"
+
+# Matrix rooms to bridge to Meshtastic channels.
+matrix_meshtastic_relay_matrix_rooms_list:
+  - id: "#meshtastic:{{ matrix_domain }}"
+    meshtastic_channel: "0"
+```
+
+By default, the bot's Matrix ID is `@meshtasticbot:{{ matrix_domain }}`. To change it, adjust `matrix_meshtastic_relay_matrix_bot_user_id`.
+
+### Bluetooth (BLE) connections
+
+When `matrix_meshtastic_relay_connection_type` is `ble`, the container runs with `--network=host` and bind-mounts the host's DBus socket — both are required for Bluetooth pairing/communication. Only use this connection type if you trust the playbook-managed host and are comfortable with these privileges.
+
+### Serial connections
+
+When `matrix_meshtastic_relay_connection_type` is `serial`, the host device referenced by `matrix_meshtastic_relay_serial_port` is passed through to the container. Make sure that `matrix_user_uid` / `matrix_user_gid` have read/write access to that device (e.g. by adding the matrix user to the `dialout` group, or adjusting udev rules).
+
+### Extending the configuration
+
+There are some additional things you may wish to configure about the bridge.
+
+Take a look at:
+
+- `roles/custom/matrix-bridge-meshtastic-relay/defaults/main.yml` for some variables that you can customize via your `vars.yml` file. You can override individual `matrix_meshtastic_relay_*` variables, or make finer-grained adjustments via `matrix_meshtastic_relay_configuration_extension_yaml`.
+
+## Installing
+
+After configuring the playbook, run the playbook 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,start
+```
+
+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. Note these shortcuts run the `ensure-matrix-users-created` tag too.
+
+## Usage
+
+Invite the bot to the Matrix rooms listed in `matrix_meshtastic_relay_matrix_rooms_list` and it will relay between Matrix and the corresponding Meshtastic channel. Messages sent on Meshtastic will appear in Matrix and vice versa.
+
+See the [project's wiki](https://github.com/jeremiah-k/meshtastic-matrix-relay/wiki) for details about commands, plugins and advanced usage.
+
+## Troubleshooting
+
+As with all other services, you can find the logs in [systemd-journald](https://www.freedesktop.org/software/systemd/man/systemd-journald.service.html) by logging in to the server with SSH and running `journalctl -fu matrix-meshtastic-relay`.

docs/configuring-playbook.md

@@ -182,6 +182,8 @@ Bridges can be used to connect your Matrix installation with third-party communi
 
 - [Setting up Heisenbridge bouncer-style IRC bridging](configuring-playbook-bridge-heisenbridge.md)
 
+- [Setting up a Matrix <-> Meshtastic bridge](configuring-playbook-bridge-meshtastic-relay.md)
+
 - [Setting up WeChat bridging](configuring-playbook-bridge-wechat.md)
 
 ### Bots