Rocket.Chat

Rocket.Chat is a free, open-source team chat platform you run on your own server instead of handing every conversation to Slack, Microsoft Teams, or Discord. Channels, direct messages, threads, voice and video calls, and a marketplace of extensions all ship in one self-hosted stack, with messages staying on hardware you control rather than a vendor’s cloud.

What Rocket.Chat actually does

Underneath the Slack-like interface, channels, DMs, private groups, threads, emoji reactions, Rocket.Chat runs on a Meteor/Node.js server backed by MongoDB, with WebRTC-based voice and video calls built in rather than bolted on through a third-party integration. Federation over the Matrix protocol lets a Rocket.Chat workspace talk to other Matrix-compatible servers, and the Omnichannel module turns the same server into a livechat widget for a website, routing customer conversations to agents alongside internal team chat.

Authentication covers LDAP, SAML, and OAuth2/OIDC out of the box, so it slots into an existing identity provider like Authentik instead of managing its own separate user database. The Apps-Engine marketplace adds bots, integrations, and custom slash commands without touching the core server, and a full REST and realtime API means most of what the web client does is scriptable.

Installing Rocket.Chat with Docker

Rocket.Chat’s own documentation points to Docker Compose as the recommended install path, via the official rocketchat-compose repository. The one detail that trips up a first install: MongoDB has to run as a replica set, even a single-node one, because Rocket.Chat relies on MongoDB’s oplog for realtime change streams. Skip that step and the server logs connection errors instead of starting.

services:
  rocketchat:
    image: registry.rocket.chat/rocketchat/rocket.chat:8.5.0
    restart: unless-stopped
    environment:
      MONGO_URL: "mongodb://mongodb:27017/rocketchat?replicaSet=rs0"
      MONGO_OPLOG_URL: "mongodb://mongodb:27017/local?replicaSet=rs0"
      ROOT_URL: "http://localhost:3000"
      PORT: 3000
      DEPLOY_METHOD: docker
    depends_on:
      - mongodb
    ports:
      - "3000:3000"

  mongodb:
    image: docker.io/mongodb/mongodb-community-server:8.0-ubi8
    restart: unless-stopped
    volumes:
      - mongodb_data:/data/db
    command: ["--replSet", "rs0", "--oplogSize", "128"]

  mongodb-init-replica:
    image: docker.io/mongodb/mongodb-community-server:8.0-ubi8
    restart: "no"
    depends_on:
      - mongodb
    command: >
      mongosh mongodb://mongodb:27017 --eval
      'rs.initiate({ _id: "rs0", members: [ { _id: 0, host: "mongodb:27017" } ] })'

volumes:
  mongodb_data:

1. Save the file as docker-compose.yml in its own directory, then run docker compose up -d.
2. The mongodb-init-replica service runs once, initializes the single-node replica set, and exits; that’s expected, not a crash.
3. Open http://your-server-ip:3000 and complete the setup wizard to create the first admin account and name the workspace.
4. For anything beyond a handful of testers, put a reverse proxy with a real TLS certificate in front of port 3000, the same way you would for Vaultwarden.

docker compose up -d

Locking down a first install

Rocket.Chat vs Mattermost, Zulip, and Matrix/Element

Mattermost is the closest comparison: also open source at its core, also Slack-shaped, also gates advanced features (extra SSO variety, compliance exports) behind a paid Enterprise edition. Zulip leans on threaded topics inside channels as its main organizing idea rather than flat channel history, which some teams prefer for high-volume discussion. Matrix, through clients like Element, is a federation-first protocol rather than a single platform, better suited to talking across organizations than replacing one company’s internal Slack.

	Rocket.Chat	Mattermost	Zulip	Matrix/Element
License	MIT (core), separate EE tier	MIT (core), separate EE tier	Apache-2.0	Apache-2.0 (Element), AGPL (Synapse)
Model	Single self-hosted platform	Single self-hosted platform	Single self-hosted platform	Federated protocol + clients
Voice/video	Built-in WebRTC	Plugin-based (Calls plugin)	Jitsi integration	Built-in via Matrix VoIP
Livechat/Omnichannel	Built-in	Not built-in	Not built-in	Not built-in
Database	MongoDB (replica set required)	PostgreSQL or MySQL	PostgreSQL	PostgreSQL (Synapse)

Rocket.Chat: pros and cons

• Built-in voice/video calls and Omnichannel livechat, no third-party plugin needed for either
• LDAP, SAML, and OAuth2/OIDC support out of the box for slotting into an existing identity provider
• Active project with a six-month support window per release and frequent security patches
• Apps-Engine marketplace and full REST/realtime API for bots and integrations

• MongoDB replica-set requirement adds real setup friction compared to a single Postgres container
• Some enterprise features, advanced auditing, some SSO variants, sit behind the paid EE tier, not the free core
• Heavier resource footprint than a lightweight chat tool; the documented floor is 2 vCPU/4 GB for the app alone, before MongoDB
• Default GridFS file storage isn’t recommended past small scale, so object storage becomes a near-mandatory extra piece

Rocket.Chat earns its keep once a team outgrows a single Discord server or wants Slack’s interface without Slack’s per-seat pricing or data residency questions. Pair it with Authentik for centralized login, and keep an eye on the containers with Uptime Kuma once real conversations depend on it staying up.

FAQ

Is Rocket.Chat really free?

Yes. The core is MIT licensed and covers messaging, channels, calls, Omnichannel, and the Apps-Engine marketplace. Rocket.Chat Enterprise Edition is a separate paid tier for advanced administration and compliance features, layered on top of, not required by, the free core.

Why does MongoDB need to be a replica set?

Rocket.Chat watches MongoDB’s oplog to push realtime updates to connected clients, and the oplog only exists when MongoDB runs in replica-set mode. A single-node replica set satisfies the requirement for testing and small deployments; production setups should use the 3-member replica set Rocket.Chat’s own docs recommend for high availability.

Can Rocket.Chat replace Slack for a small team?

For most day-to-day use, yes, channels, threads, DMs, and calls cover the same ground. The gaps show up around polish in some mobile edge cases and marketplace breadth, where Slack’s larger third-party ecosystem still leads.

Does Rocket.Chat support end-to-end encryption?

Yes, for direct messages and private channels, opt-in per room rather than on by default. It’s separate from the transport-level HTTPS a reverse proxy provides in front of the server.

Is Rocket.Chat actively maintained?

Yes. The project shipped release 8.5.0 in June 2026, has logged nearly 30,000 commits, and sits at over 45,000 GitHub stars with a steady release cadence and a documented six-month support window per version.