Self-Host Matrix (Synapse) on a VPS — Your Own Private Chat Server

A Note on the Domain

Matrix uses two names: the server name (the part after the colon in @user:example.com) and the actual hostname Synapse runs on. Keeping them the same domain is simplest. This guide assumes you own example.com and will serve Synapse at matrix.example.com, with the server name delegated to it.

Step 1: Install Docker

curl -fsSL https://get.docker.com | sh

Step 2: Generate the Config

Synapse ships a one-shot generator. Run it to create the config, then edit it:

mkdir -p synapse-data
docker run --rm \
  -v $(pwd)/synapse-data:/data \
  -e SYNAPSE_SERVER_NAME=example.com \
  -e SYNAPSE_REPORT_STATS=no \
  matrixdotorg/synapse:latest generate

Step 3: Compose with Caddy HTTPS

Save as docker-compose.yml:

services:
  synapse:
    image: matrixdotorg/synapse:latest
    restart: always
    volumes:
      - ./synapse-data:/data

  caddy:
    image: caddy:2-alpine
    restart: always
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - ./Caddyfile:/etc/caddy/Caddyfile
      - caddy_data:/data
    depends_on:
      - synapse

volumes:
  caddy_data:

Step 4: The Caddyfile (with Delegation)

The extra example.com block tells other servers where to find yours (well-known delegation), so your user IDs can be the clean @you:example.com:

matrix.example.com {
  reverse_proxy synapse:8008
}

example.com {
  handle /.well-known/matrix/server {
    header Content-Type application/json
    respond `{"m.server": "matrix.example.com:443"}`
  }
}

Bring it up:

docker compose up -d

Step 5: Create Your Account

Registration is closed by default (good). Create your admin user from the command line:

docker compose exec synapse register_new_matrix_user -c /data/homeserver.yaml http://localhost:8008

Now log in with any Matrix client (Element is the popular one), using matrix.example.com as the homeserver. Turn on end-to-end encryption in your rooms and you have private chat no platform can read.

What It Costs

A personal or small-group Synapse runs on the Standard plan (2 vCPU, 4 GB); federation and media add some load, so give it a little headroom. On NoctHost that is hourly billing from a prepaid balance topped up with crypto — no card, no KYC — which matches the point of running your own chat server: no company in the middle.