Julien Gautier
b6e43565c3
Pin the session-state architecture: the browser carries only an opaque
crypto-random session id in __Host-portal_session, signed with
SESSION_SECRET. The payload (userId, audience, curated claims, encrypted
tokens, timestamps) lives in self-hosted Redis, accessed via the standard
express-session + connect-redis pair under the NestJS Express adapter.
The id_token / access_token / refresh_token tuple is encrypted with
AES-256-GCM before being stored - per-record IV, GCM auth tag - using
SESSION_ENCRYPTION_KEY. A Redis snapshot or memory dump alone is not
enough to forge a working session; the encryption key must also be
compromised. Tampered or wrong-key records are rejected and audited.
TTL policy: idle 30 min sliding (TTL refreshed on each request) +
absolute 12 h (checked in a global interceptor, triggers DEL on expiry).
Topology: Redis Sentinel (3+ nodes) in prod with TLS and ACL; single node
in dev. Operational specifics deferred to a phase-3 infrastructure ADR.
Revocation is immediate (DEL session:{id}). A secondary index
user_sessions:{userId} supports per-user listing and force-logout. No
PostgreSQL mirror; historical trace lives in the future audit-log ADR.
decisions/README.md index updated. CLAUDE.md gains an explicit 'Sessions'
line pointing to ADR-0010.
Architectural Decision Records
This project records architecturally-significant decisions as ADRs in the MADR 4.0.0 format. References: adr.github.io.
Why ADRs
ADRs capture the why behind a decision — context, drivers, options considered, trade-offs accepted — at the moment the decision is made. They make architecture reviewable, onboarding faster, and prevent the same debate from being re-litigated later.
Conventions
- Format: MADR 4.0.0. Start from template.md.
- Filename:
NNNN-kebab-case-title.md, e.g.0007-adopt-tailwind-for-design-tokens.md. - Numbering: globally sequential 4-digit prefix. Numbers never reset, never get reused — even when an ADR is superseded or deprecated.
- Layout: flat folder. ADRs are not nested into category subfolders; topical organization happens via tags.
- Tags: every ADR carries a
tags:array in the MADR frontmatter, drawn from the tag vocabulary below. An ADR may carry several tags. Propose new tags (or renames) in the same PR that needs them; never invent ad-hoc tags inline. - Status lifecycle:
proposed→accepted→ optionallydeprecatedorsuperseded by [ADR-NNNN](NNNN-other.md). Update the YAML frontmatter; never delete an ADR. - Index maintenance: every ADR addition or status change must update the Index below in the same commit.
When to write an ADR
Write one whenever a development decision is non-trivial: tool or library choice, framework pattern, security control, perf budget, a11y target, naming convention, deprecation, breaking change, or any choice that future contributors would benefit from understanding the why of.
Tag vocabulary
The vocabulary below is the source of truth. It is intentionally coarse — propose extensions only when an existing tag genuinely doesn't fit, and avoid overly narrow tags.
| Tag | Scope |
|---|---|
frontend |
UI, Angular, components, design system, client-side state |
backend |
API, BFF, server-side services |
security |
AuthN, AuthZ, sessions, CSP, dependency scanning, secret management |
performance |
Perf budgets, caching, bundle size, Lighthouse |
accessibility |
WCAG, a11y testing, keyboard, ARIA, contrast |
infrastructure |
CI/CD, hosting, deployment, runtime |
observability |
Logs, metrics, traces, correlation IDs, monitoring |
data |
Persistence, schemas, migrations, data flow |
process |
Team conventions, workflows, repo policy |
Status: starter vocabulary, to be refined as ADRs accumulate. Update this table whenever a tag is added, renamed, or retired.
Index
ADRs are listed in numerical order. To slice by topic, filter on the Tags column.
| # | Title | Status | Tags | Date |
|---|---|---|---|---|
| 0001 | Use ADRs to record architectural decisions | accepted | process |
2026-04-29 |
| 0002 | Adopt Nx monorepo with the apps preset |
accepted | infrastructure, frontend, backend |
2026-04-29 |
| 0003 | Workspace and app naming convention | accepted | process |
2026-04-29 |
| 0004 | Frontend stack — Angular (latest LTS), standalone, zoneless, Signals, CSR-only, Vitest | accepted | frontend |
2026-04-29 |
| 0005 | Backend stack — NestJS over Express, Fastify, Hono | accepted | backend |
2026-04-29 |
| 0006 | Persistence — PostgreSQL with Prisma | accepted | data, backend |
2026-04-29 |
| 0007 | Pre-commit hooks and Conventional Commits | accepted | process |
2026-04-29 |
| 0008 | Identity model — multi-tenant Entra ID for workforce, dual-audience design for future External ID | accepted | security, data |
2026-04-29 |
| 0009 | Authentication flow — OIDC Authorization Code + PKCE via MSAL Node, BFF session pattern | accepted | security, backend |
2026-04-29 |
| 0010 | Session management — opaque session IDs in cookies, payload in self-hosted Redis with AES-GCM at rest | accepted | security, backend, infrastructure |
2026-04-29 |