License
Short version:
- The Mercure protocol is open. Anyone can implement it, including in proprietary software.
- The Mercure.rocks Hub is licensed under AGPL-3.0. Modifications to the hub itself must be shared.
- Software that uses the hub (publishers, subscribers, your application) is not affected by the AGPL. Use any license you want: proprietary, MIT, GPL, anything.
- For organizations that can't use AGPL software, commercial licenses are available.
#The Mercure protocol license
The Mercure specification is published under the IETF copyright policy. It can be implemented by any software, including proprietary software, with no royalty or attribution requirement.
#The Mercure.rocks reference hub license
The Mercure.rocks Hub (this repository) is AGPL-3.0.
In practice:
- Running the hub. No restriction on who runs it or for what purpose.
- Modifying the hub. Your modifications must be made available under AGPL-3.0 to anyone you give the modified version to: including users who interact with it over a network.
- Publishers and subscribers. Software that talks to the hub over the protocol does not become AGPL. The AGPL is about the hub binary itself, not anything that connects to it. A proprietary backend that publishes to a Mercure hub stays proprietary.
This is the same shape of license as MongoDB Community pre-SSPL: it lets anyone use the hub freely while preventing third parties from running modified versions as a proprietary SaaS without contributing back.
#Commercial licenses
If your organization can't use AGPL-3.0 (some compliance teams refuse it categorically), commercial licenses are available:
- Self-Hosted Mercure: comes with a commercial license to the binary, plus the multi-node transports and direct support. Pricing starts at €1,500/year.
- Custom licensing for cases that don't fit either option: contact@mercure.rocks.
The commercial license is grant-based and doesn't require contributing modifications back. Your legal team can review the terms before purchase.
#Mercure trademarks
"Mercure" and "Mercure.rocks" are trademarks of Dunglas Services SAS. The trademarks are not licensed under the AGPL: you can't use them in the name of your own product without permission. Implementations that pass the conformance tests may describe themselves as "compatible with the Mercure protocol."
#Contributing to the Mercure.rocks hub
Contributions are welcome under AGPL-3.0. By submitting a pull request you agree to license your contribution under the same terms as the rest of the project. See CONTRIBUTING.md for the development workflow.
#Mercure patent grant
The AGPL-3.0 includes an explicit patent grant from contributors. The protocol itself, published as an IETF Internet-Draft, is subject to the IETF's patent policy.
#Mercure licensing questions
For licensing questions that aren't answered here, email contact@mercure.rocks.