julien
883c5151de
## Summary Step 3 of the AI-relay chantier (after #194 ADR and #195 client skeleton). Wires the BFF-side **live surface** that the SPA's future chatbot widget will consume. [ADR-0024](docs/decisions/0024-ai-service-relay-grpc-sse-bridge.md) is promoted from `proposed` to `accepted` in the same change. Three end-user routes under `/api/ai/*`, gated by the active portal session (no `@RequireAdmin` — AI is a regular-user surface): | Route | Verb | Wire | Maps to | |---|---|---|---| | `/api/ai/chat` | `POST` | `text/event-stream` | `apf.ai.v1.ChatService.Chat` (server-stream) | | `/api/ai/rag/search` | `GET` | `application/json` | `apf.ai.v1.RagService.Search` (unary) | | `/api/ai/models` | `GET` | `application/json` | `apf.ai.v1.ModelsService.ListModels` (unary) | CSRF and session validation are delegated to the global middleware mounted in `main.ts` (per [ADR-0009](docs/decisions/0009-auth-flow-oidc-pkce-msal-node.md) and [ADR-0021](docs/decisions/0021-phase-2-security-baseline.md)); the controller asserts `req.session.user` and emits 401 if absent. ## What lands ### `apps/portal-bff/src/grpc/ai-bridge/` ``` ai-bridge/ ├── ai-bridge.module.ts imports AiClientModule, exports the controller ├── ai-bridge.controller.ts 3 routes — POST chat (SSE), GET rag/search, GET models ├── sse.writer.ts ChatEvent oneof → SSE frame translator ├── sse.writer.spec.ts unit tests for the codec ├── ai-bridge.controller.spec.ts end-to-end against an in-process fake gRPC server └── dto/ ├── chat-request.dto.ts class-validator body shape (POST /chat) └── rag-search-query.dto.ts class-validator query shape (GET /rag/search) ``` ### SSE codec (`sse.writer.ts`) Each `ChatEvent` oneof case becomes one SSE frame with a kebab-case `event:` name and a JSON-encoded `data:` payload: ``` event: token data: {"token":"…","value":"…"} event: agent-step data: {"agent":"…","step":"…","stepId":"…"} event: tool-call data: {"callId":"…","name":"…","args":{…}} event: done data: {"stats":{"tokensIn":…,"tokensOut":…,"chunksRetrieved":…}} ``` A helper `relayErrorFrame(code, message, retriable)` synthesises a relay-side `event: error` frame that matches the AI service's own `ErrorEvent` shape — the SPA's renderer needs no second code path for relay-level failures vs upstream model errors. gRPC status codes map into the `urn:apf-ai:*` namespace (`UNAVAILABLE` → `urn:apf-ai:unavailable`, `DEADLINE_EXCEEDED` → `urn:apf-ai:timeout`, `PERMISSION_DENIED` → `urn:apf-ai:permission_denied`, `RESOURCE_EXHAUSTED` → `urn:apf-ai:rate_limited`, `INVALID_ARGUMENT` → `urn:apf-ai:invalid_argument`, anything else → `urn:apf-ai:relay_error`). The terminal `done` frame closes the stream — no `[DONE]` sentinel, per ADR-0024. ### Controller (`ai-bridge.controller.ts`) - `POST /api/ai/chat` — builds an `apf.ai.v1.ChatRequest` from the validated DTO + session-derived Principal, calls `ChatClient.chat()`, drains the `ClientReadableStream<ChatEvent>` into SSE frames written on the raw Express `Response`. `req.on('close', …)` propagates browser disconnect through an `AbortController` into `call.cancel()` so the upstream LLM stops (per `apf-ai-service/docs/streaming.md`). - `GET /api/ai/rag/search` — unary RAG call. `topK` defaults to 0 (server picks the default). `source` and `documentId` query params surface the same filter fields the upstream RPC accepts. - `GET /api/ai/models` — unary lookup of the provider catalogue. The SSE writes happen on the raw Express response (manual `setHeader` + `flushHeaders` + `write` + `end`) rather than through NestJS's `@Sse()` decorator, because `@Sse()` is GET-only and the chat endpoint is POST (the SPA carries the conversation history in the body). ### Lifecycle hooks `AiClientModule` now implements `OnApplicationShutdown` and closes the four gRPC stubs (Chat / Rag / Ingestion / Models). The four stubs share the same HTTP/2 channel (gRPC-js dedups on `endpoint + credentials`), so the `close()` calls are cheap, but kept explicit so adding a fifth stub later is an obvious one-line addition. `main.ts` now calls `app.enableShutdownHooks()` so `SIGTERM` / `SIGINT` / `SIGHUP` actually route through the lifecycle interface. ### DTOs `ChatRequestDto` constrains: - `messages` — 1 to 64 entries; each has `role ∈ {user, assistant, system}` (no `tool` — tool messages are constructed BFF-side per ADR-0024 §"Tool-dispatch contract") and `content` ≤ 16 KB. - `conversationId`, `model`, `provider` — optional, ≤ 64 / 128 chars. `RagSearchQueryDto`: - `query` — required, non-empty. - `topK` — optional, integer in `[1, 50]` (the AI service has its own cap; the BFF rejects out-of-range values early). - `source` / `documentId` — optional pass-through filters. ### Documentation - ADR-0024 frontmatter: `status: proposed` → `accepted`. - `docs/decisions/README.md` index reflects the new status. - `CLAUDE.md` Architecture section grows an "AI service relay" bullet; the roll-up line moves from "ADRs 0001 → 0023" to "0001 → 0024"; the shipped-on-main list grows an "AI relay surface" entry. - `apps/portal-bff/.env.example` documents `AI_SERVICE_GRPC_ENDPOINT` / `AI_SERVICE_CLIENT_ID` / `AI_SERVICE_GRPC_TLS` and points operators at `apf-ai-service`'s own docker-compose for the runtime dependency. ## Notes for the reviewer - **No live AI service in this PR's local-dev stack.** `apf-ai-service` runs from its own repo (`/home/jgautier/Works/apf-ai-service`) with its own `infra/docker-compose.yml`. The BFF dials `localhost:8080` by default — the host-published port of the AI service's container. This is option (a) from ADR-0024 §"Open question — Compose orchestration": two independent stacks, dial across via host networking. Merging the compose files into one would couple two release cadences without operational payoff. - **Tests run against an in-process fake `grpc.Server`.** All five spec cases on the controller wire it up against a fake `ChatService` + `RagService` + `ModelsService` server bound to `127.0.0.1:0` (random port). No mocks — the controller's gRPC client makes a real connection, real serialisation, real cancellation propagation. Cost: ~0.5 s overhead from the gRPC server setup. - **CSRF + session middleware are unchanged.** The new POST endpoint is protected by the existing double-submit CSRF middleware mounted in `main.ts` (per [ADR-0021](docs/decisions/0021-phase-2-security-baseline.md)). The SPA's fetch call needs to send the `X-CSRF-Token` header matching the `__Host-portal_csrf` cookie — same protocol as every other POST in the BFF. No per-controller wiring required. - **Manual session check rather than a guard.** Three reasons: (1) matches the existing pattern in `me.controller.ts`; (2) the session check is the only authorization gate (no roles to evaluate) — a guard would add ceremony without payoff; (3) the SSE controller already takes control of the response object (`@Res()`), which `UseGuards` interacts with awkwardly. Throwing `UnauthorizedException` lets `StructuredErrorFilter` produce the 401 envelope before any header is flushed. - **Why the controller does NOT use `@Sse()`.** NestJS's `@Sse()` decorator is GET-only and emits frames from `Observable<MessageEvent>`. The chat endpoint is POST (the SPA sends conversation history in the body) and the source is a Node `Readable` stream from `@grpc/grpc-js`. Manual response handling is simpler than adapting to / from `Observable` for a single consumer. - **Cancellation contract.** When the SPA aborts the fetch, the browser closes the TCP connection, Express emits `'close'` on the request, the controller's `AbortController.abort()` triggers, `ChatClient` calls `.cancel()` on the gRPC stream, the AI service's `ServerCallContext.CancellationToken` cancels the upstream LLM. The spec covers the `'close'` → server-side `cancelled` event end-to-end. - **No ingestion route in the BFF.** Per ADR-0024 §"Out of scope", v1 admin ingestion uses the `apf-ai-service/tools/Apf.Ai.Ingest/` CLI. A future PR adds the BFF endpoint when the admin "manage AI corpus" surface ships. `IngestionClient` remains in `AiClientModule` so that future PR is one new file, not a new module plus a new client. - **No bundle-size or perf surprise.** The BFF is a Node process, not a SPA chunk — bundle budgets don't apply. The gRPC channel is opened lazily on first call; idle BFFs incur no upstream TCP cost. ## Test plan - [x] `pnpm nx test portal-bff` — **461 specs pass** (was 443; +13 new: 8 SSE writer cases + 5 controller end-to-end cases against the in-process fake server). Worker-exit-leak warning persists from the gRPC server's slow shutdown — pre-existing pattern from PR #195; harmless. - [x] `pnpm nx lint portal-bff` — 6 pre-existing warnings, no new ones from the diff. - [x] `pnpm nx build portal-bff` — clean webpack compile. - [x] Module wiring: `AppModule` imports `AiBridgeModule`, which imports `AiClientModule`. Resolves cleanly through DI; the audit-side `HashUserIdService` is satisfied by `AiClientModule`'s local provider (per the rationale recorded in PR #195's `AiClientModule` docstring). - [ ] **Manual smoke** — bring up `apf-ai-service` from its own repo (`cd ../apf-ai-service && docker compose -f infra/docker-compose.yml up`), set `AI_SERVICE_GRPC_ENDPOINT=localhost:8080` in `apps/portal-bff/.env`, run `pnpm nx serve portal-bff`. Sign in to `portal-shell`, then in a terminal: ```bash curl --cookie-jar /tmp/portal-session http://localhost:3000/api/auth/login # follow Entra… curl -N \ -H 'Content-Type: application/json' \ -H 'X-CSRF-Token: <copied from cookie>' \ --cookie /tmp/portal-session \ -d '{"messages":[{"role":"user","content":"hello"}]}' \ http://localhost:3000/api/ai/chat ``` Expect a streamed SSE response terminated by an `event: done` frame. Verify `GET /api/ai/rag/search?query=test` returns a JSON response. Verify `GET /api/ai/models` lists the configured providers. ## What's next 1. **PR (frontend chantier)** — chatbot widget on `portal-shell` consuming the SSE endpoint. Will use `fetch` + `ReadableStream` parsing (not native `EventSource`, since POST is needed). Drag / fullscreen / suggestion UX carries forward from the stargate POC's `ChatbotWidget.tsx`. 2. **PR (post-v1)** — proto-drift CI gate that diffs `proto/apf-ai/` against an upstream tag of `apf-ai-service`. 3. **Coordinated amendment** — when the first production deployment is in scope, both repos record the same prod-hardening choice (signed `Principal` envelope vs mTLS) on the same date. --------- Co-authored-by: Julien Gautier <julien.gautier@apf.asso.fr> Reviewed-on: #196
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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 |
| 0011 | MFA enforcement — Entra ID Conditional Access baseline, BFF claim sanity-check, step-up hooks designed-in | accepted | security |
2026-04-29 |
| 0012 | Observability — Pino structured logs + OpenTelemetry tracing, W3C Trace Context propagation, stdout + collector | accepted | observability, backend, frontend |
2026-04-29 |
| 0013 | Audit trail — separated append-only Postgres schema, decoupled from app logs | accepted | security, observability, data |
2026-04-29 |
| 0014 | Downstream API access — On-Behalf-Of pattern, unified DownstreamApiClient, audience-aware authorization |
accepted | security, backend |
2026-04-29 |
| 0015 | CI/CD pipeline — Gitea Actions, trunk-based + squash-merge, thin YAML over portable scripts | accepted | infrastructure, process |
2026-04-30 |
| 0016 | Accessibility baseline — WCAG 2.2 AA + targeted AAA, Angular CDK + spartan-ng + Tailwind, APF panel testing | accepted | accessibility, frontend, process |
2026-04-30 |
| 0017 | Performance budgets — Core Web Vitals + Lighthouse CI gates, bundle budgets, BFF p95/p99 SLOs | accepted | performance, frontend, backend, process |
2026-04-30 |
| 0018 | Environment configuration — Angular environment.ts, BFF env vars, audit pool split |
accepted | frontend, backend, infrastructure, process |
2026-05-10 |
| 0019 | Internationalisation — @angular/localize, build-time per-locale bundles, /fr + /en path-based routing |
accepted | frontend, accessibility, performance, process |
2026-05-11 |
| 0020 | portal-admin — dedicated SPA for portal administration, sharing the existing BFF |
accepted | frontend, backend, security, infrastructure, process |
2026-05-11 |
| 0021 | Phase-2 security baseline — helmet, CORS allowlist, double-submit CSRF, rate limiting, structured error envelope | accepted | security, backend |
2026-05-13 |
| 0022 | Documentation site — VitePress + Mermaid plugin, separate static deployment | accepted | process, infrastructure |
2026-05-15 |
| 0023 | Charts + dashboards — D3 + Observable Plot wrapped in libs/shared/charts |
accepted | frontend, accessibility, performance |
2026-05-16 |
| 0024 | AI service relay — vendored gRPC protos, NestJS gRPC client, SSE bridge to the SPA, POC unsigned principal | accepted | backend, security, observability |
2026-05-19 |