Solidus Relay vs a Credo-TS mediator

This page is not an argument that you should not use it.

What Credo-TS does better, first

• It is a complete framework, not a service. W3C DID and VC, DIDComm, and OID4VC in one TypeScript stack, with Node.js and React Native support, so the same library runs in your backend and your mobile app. Solidus Relay is one component; Credo is the toolbox.
• Foundation governance. It sits under the OpenWallet Foundation. That is a real, durable answer to "what happens to this project if its maintainers move on", and it is an answer Solidus cannot currently give about itself.
• It is free, and it is a library. No account, no endpoint, no third party in your data path. For many teams that is not a feature comparison, it is the whole decision.
• Ecosystem gravity. Standards-complete implementations attract integrations, and integrations attract more. That compounding is real and we are not near it.

The distinction that actually matters

Credo-TS is a framework you build a mediator with. Solidus Relay is a mediator you connect to.

Those are different products, and most of the apparent comparison dissolves once you see it. You can build a mediator with Credo and self-host it, and if that is what you want, our page on running your own is the honest continuation, not this one.

One sourced fact worth checking against your own requirements: the widely-referenced Credo-based mediator implementation (the Animo mediator, since transferred to the OpenWallet Foundation) is DIDComm v1, using Aries RFC-0211 mediation with Pickup v1/v2. Solidus Relay is v2 only. If you are building on v2, verify which generation any given mediator implementation targets before adopting it: the framework and a particular mediator built on it are not the same thing. See DIDComm v2 vs v1.

What Solidus Relay adds, and it is one thing

Admission decided by a presented credential rather than an API key, with the check running fail-closed and reporting a verdict that distinguishes "verifier unreachable" from "credential invalid", see credential-gated mediation.

That, plus resolving correspondents' did:solidus routing from the chain rather than from the requester (chain-anchored routing resolution), is the whole of our differentiation. We do not claim more coverage, more maturity, or more features. We would lose all three.

Choosing

Use Credo-TS if you want a framework, if you need one library across backend and mobile, if governance continuity matters, or if you will not put a third party in your message path.

Use Solidus Relay if you want a hosted v2 mediator now, and if credential-gated admission is something you would otherwise build yourself.

Both is normal: Credo in your agent, talking to whichever mediator you choose.