Send ephemeral messages, track and synchronize shared state, and listen to Postgres changes all over WebSockets.
Examples
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Request Features
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Report Bugs
## Status
[](https://github.com/supabase/realtime/blob/main/LICENSE)
[](https://coveralls.io/github/supabase/realtime?branch=main)
| Features | v1 | v2 | Status |
| ---------------- | --- | --- | ------ |
| Postgres Changes | ✔ | ✔ | GA |
| Broadcast | | ✔ | GA |
| Presence | | ✔ | GA |
This repository focuses on version 2 but you can still access the previous version's [code](https://github.com/supabase/realtime/tree/v1) and [Docker image](https://hub.docker.com/layers/supabase/realtime/v1.0.0/images/sha256-e2766e0e3b0d03f7e9aa1b238286245697d0892c2f6f192fd2995dca32a4446a). For the latest Docker images go to https://hub.docker.com/r/supabase/realtime.
The codebase is under heavy development and the documentation is constantly evolving. Give it a try and let us know what you think by creating an issue. Watch [releases](https://github.com/supabase/realtime/releases) of this repo to get notified of updates. And give us a star if you like it!
## Overview
### What is this?
This is a server built with Elixir using the [Phoenix Framework](https://www.phoenixframework.org) that enables the following functionality:
- Broadcast: Send ephemeral messages from client to clients with low latency.
- Presence: Track and synchronize shared state between clients.
- Postgres Changes: Listen to Postgres database changes and send them to authorized clients.
For a more detailed overview head over to [Realtime guides](https://supabase.com/docs/guides/realtime).
### Does this server guarantee message delivery?
The server does not guarantee that every message will be delivered to your clients so keep that in mind as you're using Realtime.
## Quick start
You can check out the [Supabase UI Library](https://supabase.com/ui) Realtime components and the [repository](https://github.com/supabase/multiplayer.dev) of the [multiplayer.dev](https://multiplayer.dev) demo app.
## Developers
Start with [DEVELOPERS.md](DEVELOPERS.md) for local setup, `mise` tasks, and example workflows.
Once your environment is up and running, check out the following docs to customize the server and troubleshooting:
- [ENVS.md](ENVS.md) - detailed list of all environment variables
- [ERROR_CODES.md](ERROR_CODES.md) - list of operational codes
- [OBSERVABILITY_METRICS.md](OBSERVABILITY_METRICS.md) - monitoring information
## Postgres compatibility
| `supabase/postgres` version | Role | Status |
| --------------------------------- | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| < 14 | - | Not officially supported. |
| 14.x | `supabase_admin` | Requires superuser: `log_min_messages` can only be set by a superuser; supautils doesn't expose per-parameter delegation on this version. On <= 14.5, `realtime.broadcast_changes(...)` called from a trigger via `PERFORM` is unsupported. |
| 15.x < 15.14.1.018 | `supabase_admin` | Requires superuser: `supautils.policy_grants` on `realtime.subscription` is missing until [supabase/postgres@1b916920](https://github.com/supabase/postgres/commit/1b916920). |
| 15.x >= 15.14.1.018, 16.x, 17.x | `supabase_admin` | Requires superuser to run migrations, no superuser needed for tenant grants. Policies are managed by supautils. |
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md)
## Code of Conduct
See [supabase/CODE_OF_CONDUCT.md](https://github.com/supabase/.github/blob/main/CODE_OF_CONDUCT.md)
## License
This repo is licensed under Apache 2.0.
## Credits
- [Phoenix](https://github.com/phoenixframework/phoenix) - `Realtime` server is built with the amazing Elixir framework.
- [Phoenix Channels JavaScript Client](https://github.com/phoenixframework/phoenix/tree/master/assets/js/phoenix) - [@supabase/realtime-js](https://github.com/supabase/realtime-js) client library heavily draws from the Phoenix Channels client library.
