# Matrix / Element Self-Hosted Server

A Docker Compose setup for running a self-hosted [Matrix](https://matrix.org/) homeserver (Synapse) with the [Element Web](https://element.io/) client and a Synapse admin panel.

## What's included

| Service | Image | Default Port | Purpose |
|---|---|---|---|
| **Synapse** | `matrixdotorg/synapse:latest` | `8008` | Matrix homeserver |
| **Element Web** | `vectorim/element-web:latest` | `8080` | Web chat client |
| **Synapse Admin** | `awesometechnologies/synapse-admin:latest` | `8081` | Admin UI |
| **PostgreSQL** | `postgres:14` | `5432` | Database for Synapse |

---

## Prerequisites

- [Docker](https://docs.docker.com/get-docker/) and [Docker Compose](https://docs.docker.com/compose/install/)
- A domain name pointed at your server (e.g. `chat.example.com`)
- A reverse proxy (nginx, Caddy, Traefik, etc.) to handle TLS termination — the containers themselves do not manage HTTPS

---

## Setup

### 1. Clone the repository

```bash
git clone <your-repo-url>
cd matrix
```

### 2. Configure environment variables

Copy the example env file and edit it:

```bash
cp .env.example .env
```

Open `.env` and set each value:

```dotenv
# PostgreSQL
POSTGRES_DB=synapse
POSTGRES_USER=synapse
POSTGRES_PASSWORD=<strong-random-password>

# Synapse — must match your public domain
SYNAPSE_SERVER_NAME=chat.example.com

# Synapse Admin UI
REACT_APP_SERVER=https://chat.example.com
REACT_APP_REGISTRATION_ENABLED=false   # set to true only if you want open registration
```

> **Security note:** Use a strong, unique password for `POSTGRES_PASSWORD`. Never commit `.env` to version control — it is already in `.gitignore`.

### 3. Generate the Synapse configuration

Synapse needs a `homeserver.yaml` generated before it can start. Run this once:

```bash
docker run --rm \
  -e SYNAPSE_SERVER_NAME=chat.example.com \
  -e SYNAPSE_REPORT_STATS=yes \
  -v "$(pwd)/synapse-data:/data" \
  matrixdotorg/synapse:latest generate
```

Replace `chat.example.com` with your actual domain. This creates `synapse-data/homeserver.yaml`.

### 4. Point Synapse at PostgreSQL

Open `synapse-data/homeserver.yaml` and replace the default SQLite database block with:

```yaml
database:
  name: psycopg2
  args:
    user: synapse
    password: <your-POSTGRES_PASSWORD>
    database: synapse
    host: postgres
    cp_min: 5
    cp_max: 10
```

Use the same credentials you set in `.env`.

### 5. Configure the Element Web client

Copy the example config and edit it:

```bash
cp element-config.json.example element-config.json
```

Update every occurrence of `chat.example.com` to your domain:

```json
{
  "default_server_config": {
    "m.homeserver": {
      "base_url": "https://chat.example.com",
      "server_name": "chat.example.com"
    }
  },
  "disable_custom_urls": true,
  "brand": "My Matrix Server",
  "showLabsSettings": true,
  "voip": {
    "stun_servers": [
      { "urls": ["stun:turn.example.com:3478"] }
    ],
    "turn_servers": [
      {
        "urls": [
          "turn:turn.example.com:3478?transport=udp",
          "turn:turn.example.com:3478?transport=tcp",
          "turns:turn.example.com:5349?transport=tcp"
        ],
        "secret": "<your-turn-server-secret>",
        "expiry": 86400000
      }
    ]
  }
}
```

If you do not have a TURN server, remove the `voip` and `webrtc` blocks entirely. Voice/video calls on the same local network will still work without them.

### 6. Start the stack

```bash
docker compose up -d
```

Verify all containers are running:

```bash
docker compose ps
```

Check Synapse logs for errors:

```bash
docker compose logs -f synapse
```

### 7. Create your first admin user

Once Synapse is running, register an admin account:

```bash
docker compose exec synapse register_new_matrix_user \
  -c /data/homeserver.yaml \
  -u <username> \
  -p <password> \
  -a \
  http://localhost:8008
```

The `-a` flag grants admin privileges. You can omit it for regular users.

---

## Reverse proxy / TLS

The containers expose plain HTTP. You must front them with a reverse proxy that terminates TLS. A minimal **nginx** example:

```nginx
server {
    listen 443 ssl;
    server_name chat.example.com;

    ssl_certificate     /etc/letsencrypt/live/chat.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/chat.example.com/privkey.pem;

    # Element Web
    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }

    # Synapse Matrix API and federation
    location /_matrix {
        proxy_pass http://127.0.0.1:8008;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        client_max_body_size 50M;
    }

    location /_synapse {
        proxy_pass http://127.0.0.1:8008;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
    }
}
```

For automatic TLS with Let's Encrypt, use [Certbot](https://certbot.eff.org/) or [Caddy](https://caddyserver.com/).

### Matrix federation (optional)

If you want other Matrix homeservers to be able to communicate with yours, port `8448` must be reachable publicly. You can either:

- Add a second `server { listen 8448 ssl; ... }` block that proxies to `http://127.0.0.1:8008`, or
- Add a `.well-known/matrix/server` file served from your domain pointing federation to port 443

---

## Accessing the services

| URL | Service |
|---|---|
| `https://chat.example.com` | Element Web client |
| `https://chat.example.com:8081` | Synapse Admin panel |
| `https://chat.example.com/_matrix` | Matrix homeserver API |

Log into the admin panel at port `8081` using the admin credentials you created in step 7.

---

## Data persistence

All persistent data is stored in local directories that are bind-mounted into the containers:

| Directory | Contents |
|---|---|
| `postgres-data/` | PostgreSQL database files |
| `synapse-data/` | Synapse config, media uploads, signing keys |

Both directories are excluded from git via `.gitignore`. **Back them up regularly.**

---

## Upgrading

Pull the latest images and recreate the containers:

```bash
docker compose pull
docker compose up -d
```

Check the [Synapse changelog](https://github.com/element-hq/synapse/blob/master/CHANGES.md) before upgrading major versions — some releases require manual migration steps.

---

## Troubleshooting

**Synapse fails to start with a database error**
Make sure the credentials in `synapse-data/homeserver.yaml` match those in `.env`, and that the `postgres` service is fully healthy before Synapse starts. You can force the order with:
```bash
docker compose up -d postgres
# wait a few seconds, then:
docker compose up -d synapse element-web element-admin
```

**Element Web shows "Homeserver is not reachable"**
Verify that `base_url` in `element-config.json` uses `https://` and points to the domain your reverse proxy serves (not `localhost`).

**"M_FORBIDDEN" when registering users**
Open registration is disabled by default. Either use the `register_new_matrix_user` command (step 7) or set `enable_registration: true` in `homeserver.yaml` and restart Synapse.

**Port conflicts**
If any default port is already in use on your host, change the left side of the port mapping in `docker-compose.yml` (e.g. `"8082:80"` for Element Web) and update your reverse proxy accordingly.