Mercure documentation

Mercure is a real-time protocol built on HTTP and Server-Sent Events. The reference hub is open-source (AGPL-3.0), production-ready, and used to push billions of messages a month.

This documentation covers the protocol and the Mercure.rocks Hub for the 1.0 release. If you're upgrading from 0.x, start with the upgrade guide.

Get started with Mercure

• Introduction: what Mercure is and when to reach for it

• Quickstart: running hub, first subscription, first update in five minutes

• Installation: binary, Docker, Compose, Kubernetes, AUR

Mercure core concepts

• Topics and matchers: how subscribers say what they want

• Subscribing: the SSE side

• Publishing: the POST side

• Authorization: OAuth 2.0 access tokens, authorization_details, cookies

• Discovery: finding the hub and its protected resource metadata

• Reconnection and history: Last-Event-ID, replay

• Active subscriptions: presence and the subscription API

• Encryption: JWE end-to-end

Mercure use cases

• Use cases overview

• LLM token streaming

• AI agent progress

• Live data and dashboards

• Collaborative editing

• Async jobs and progress

• Notifications

• Hotwire / Turbo Streams

• GraphQL subscriptions

Mercure hub deployment

• Configuration: Caddyfile directives and environment variables

• Docker

• Kubernetes

• Reverse proxies: NGINX and Traefik

• GitHub Actions

Running Mercure in production

• High availability: scaling beyond one node

• Rolling updates: graceful shutdown for SSE

• Health checks and monitoring

• Tracing: OpenTelemetry spans

• Load testing

• Debugging

• Troubleshooting

Mercure protocol reference

• Protocol: the IETF specification

• FAQ

• License

• Upgrade guide

Mercure ecosystem

• Awesome Mercure: libraries, integrations, demos

• Conformance tests

Mercure support and community

• GitHub Discussions for community questions

• Stack Overflow mercure tag

• #mercure on the Symfony Slack

• Cloud and Enterprise support: contact@mercure.rocks