ADR 0002 — Auth: better-auth 1.7 in ddx-api

Status

Accepted 2026-10-23 (owner Q1, confirmed by Q13).

Context

The operator asked for "advanced auth V5". Read as feature parity with the HMS Auth.js v5 beta: credentials, WebAuthn passkey and the org in the session (Q1). The workspace also needs teams, access control, API keys (service and user scope) and a JWT that ddx-api issues and verifies. Evidence: ../research/rq3-auth-matrix.md. Harness canon: better-auth 1.7 for new projects, Auth.js v5 legacy only (~/.claude/ddx-topic-flows/VERSIONS.md betterauth1).

Decision

Use better-auth 1.7 inside ddx-api, with the organization plugin (teams + access control), apiKey, passkey and jwt plugins. ddx-api issues the JWT; ddx-web reaches auth only through the BFF api/v1. Auth data lives in ddx_auth (ADR 0004). In ddx-web, proxy.ts does the optimistic cookie check and the DAL does the real check in every page and route handler.

Rejected alternative

Auth.js v5. Rejected: no built-in organizations, teams, access control or API keys; WebAuthn is experimental; it does not issue a JWKS-backed JWT for a separate backend. Each gap would be custom code. It is legacy in the harness canon.

Consequences

• One credential stack, three credential types (session, user API key, service API key) in one ddx-api guard chain — RQ9 designs the chain.
• Plugin option names are checked against the installed types at scaffold time.
• nextCookies() goes LAST if any better-auth client runs in ddx-web.

• ddx-documentation — dudoxx-web-boot

adr/

• ADR 0001 — Scaffold route: dudoxx-sandbox-creator with 163XX overrides
• ADR 0002 — Auth: better-auth 1.7 in ddx-api
• ADR 0003 — Route shape: org slug, role, [entity]/[id], ?view=
• ADR 0004 — Database split: one Postgres 18 instance, six databases
• ADR 0005 — Frameworks and the approved dependency table
• ADR 0006 — API clients come from one factory
• ADR 0007 — Typed service container (DI / IoC)
• ADR 0008 — Singleton scope: what may live at module level
• ADR 0009 — One variant API for every inventory component
• ADR 0010 — Media path: presigned URLs from ddx-api after the org check
• ADR 0011 — Media proxy: MinIO only through ddx-api
• ADR 0012 — Density names: compact | cosy | large
• ADR 0013 — Platform super-admin acts as org-admin of the target org
• ADR 0014 — Unified settings: one registry, three tiers, one resolve in ddx-api
• ADR 0015 — Entity kernel: one descriptor, one access seam, one projection, one proof chain
• ADR 0016 — SSE Bus: Redis Streams log, Redis pub/sub fan-out, BullMQ outbound queue
• ADR 0017 — Layered BFF: one route table, route classes, read models
• ADR 0018 — Cluster node registry, node identity, hot plug
• Debug overlay

deploy/

• Deploy runbook — dudoxx-web-boot
• Entity kernel — guide
• Feature map — what each role can do
• Component inventory
• Naming constitution — dudoxx-web-boot
• Observability — one log layout, one key set
• Pattern reference — P1-P23 and groups A-K
• Port map — dudoxx-web-boot

research/

• RQ1 — Which release is "latest", and does it differ from the canon?
• RQ10 — SSE through the Next.js BFF route handler (desk half)
• RQ11 — Dev latency baseline: cold compile per route + next-server RSS
• RQ2 — Route group or dynamic org slug?
• RQ3 — better-auth 1.7 vs Auth.js v5: feature matrix
• RQ4 — Separate databases or separate schemas?
• RQ5 — Which frameworks beyond shadcn earn a place?
• RQ6 — How do DI, IoC and Singleton behave across RSC, client bundles and NestJS?
• RQ7 — Which data uses the server cache, which uses TanStack Query, how is each invalidated?
• RQ8 — Media path: presigned URLs vs streaming through the BFF
• Template triage — create-nextjs code in ddx-web
• Settings — guide
• Local setup — dudoxx-web-boot
• Shell tree — SiteShell and PortalShell
• SSE event catalog
• Version pins — dudoxx-web-boot