Solidus Auth
Solidus Auth vs Better Auth
Better Auth is free, MIT-licensed, self-hosted, and absorbed the actual Auth.js/NextAuth team in September 2025 — for most projects it's simply the right, no-counterparty-risk choice. Solidus doesn't replace it; the plugin that would let them compose isn't built yet.
Solidus is a public testnet: no mainnet, no token, no external audit, and no paying customer. Every claim below is checkable; none of them are a substitute for the certifications an incumbent already holds.
What Better Auth does better
- Free, MIT-licensed, self-hosted — zero deployment risk and zero protocol dependency. For most projects this is simply the right choice.
- Ships SAML 2.0, SCIM, 2FA, and Organizations in open source today, at no cost. Solidus has none of this shipped.
- Absorbed the actual Auth.js/NextAuth team in September 2025 and is now their own recommended path forward for Next.js — real ecosystem momentum, not a claim.
- The honest state of the integration: the solidus-provider Better Auth plugin does not exist yet — it's a roadmap item, not shipped code. A Better Auth developer evaluating Solidus today would be hand-integrating against an admin-gated verifier API, not installing a plugin.
Where Solidus is different
- Cross-app credential portability: the brief states plainly Better Auth is a 'library, not protocol' — every app still owns its own user table, and the same user must re-onboard per app. A did:solidus credential is portable across apps in principle.
- Protocol vs library: Better Auth gives each app primitives; Solidus shares the credential across apps by design — a different layer, not a better version of the same thing.
Side by side
| Feature | Solidus | Better Auth |
|---|---|---|
| What it actually is | Testnet-anchored OID4VP verifier + Solid-OIDC/DPoP provider | TypeScript-first OSS auth framework, MIT-licensed, self-hosted |
| Cost | $0.001/verification protocol cost, testnet | $0, MIT, no capsBetter Auth wins |
| SAML 2.0 / SCIM / 2FA / Organizations | None shipped | Shipped in OSS, freeBetter Auth wins |
| Cross-app credential portability | did:solidus — W3C-registered, portable in principle | None — brief: 'library, not protocol,' every app owns its own user table |
| Ecosystem momentum | 4-node dev committee, public testnet | Absorbed the Auth.js/NextAuth team Sept 2025; Next.js's own recommended defaultBetter Auth wins |
| Plugin / integration exists today? | No — roadmap, not shipped code | N/A — Better Auth is the platform being integrated intoBetter Auth wins |
| Maturity | Public testnet, unaudited, no paying customer | Free, stable OSS, running in production across many Next.js appsBetter Auth wins |
Check it yourself
There's no integration demo to run — the solidus-provider plugin isn't shipped. What is checkable: curl -s https://api.github.com/repos/w3c/did-extensions/pulls/713 | jq '{state,merged,merged_at}' → merged 2026-07-04, the DID method the portability claim rests on.