feat: expose recommendation streaming api

backend/app/main.py

@@ -1,16 +1,24 @@
-"""Application factory and wiring. No logic lives here."""
+"""Application factory and dependency wiring."""
 
 from collections.abc import AsyncIterator
 from contextlib import asynccontextmanager
 from pathlib import Path
 
 import httpx2
+from anthropic import AsyncAnthropic
 from fastapi import FastAPI
 from fastapi.staticfiles import StaticFiles
 
-from app.adapters.spotify.session import PendingLogins, SessionStore
+from app.adapters.anthropic.llm import AnthropicRecommender
+from app.adapters.spotify.auth import TokenSet, refresh_access_token
+from app.adapters.spotify.client import SpotifyClient
+from app.adapters.spotify.session import PendingLogins, SessionStore, SpotifySession
+from app.api.recommendations import router as recommendations_router
 from app.api.routes import router
 from app.config import AppMode, Settings, settings
+from app.observability.logging import configure_logging
+from app.observability.timing import RequestTimingMiddleware
+from app.pipeline.orchestrator import RecommendationPipeline
 
 FRONTEND_DIST = Path(__file__).parent / "static"
 
@@ -21,11 +29,11 @@ def create_app(
 ) -> FastAPI:
     """Build the FastAPI app: API routes plus the built SPA on one port."""
     active_settings = application_settings or settings
+    configure_logging(active_settings.app_mode)
 
     @asynccontextmanager
     async def lifespan(application: FastAPI) -> AsyncIterator[None]:
-        if active_settings.app_mode is AppMode.LIVE and not active_settings.spotify_client_id:
-            raise RuntimeError("SPOTIFY_CLIENT_ID is required in live mode")
+        _validate_live_settings(active_settings)
         async with httpx2.AsyncClient(
             timeout=active_settings.spotify_timeout_seconds,
             transport=http_transport,
@@ -34,7 +42,33 @@ def create_app(
             application.state.session_store = SessionStore()
             application.state.pending_logins = PendingLogins()
             application.state.settings = active_settings
-            yield
+            application.state.seed_session_id = None
+            anthropic_client = AsyncAnthropic(
+                api_key=active_settings.anthropic_api_key or "unused-demo-key"
+            )
+            application.state.anthropic = anthropic_client
+            application.state.recommendation_pipeline = RecommendationPipeline(
+                AnthropicRecommender(anthropic_client, active_settings),
+                active_settings,
+            )
+
+            def spotify_client_factory(session: SpotifySession) -> SpotifyClient:
+                return SpotifyClient(http, session, active_settings)
+
+            application.state.spotify_client_factory = spotify_client_factory
+            if (
+                active_settings.app_mode is AppMode.LIVE
+                and active_settings.spotify_seed_refresh_token
+            ):
+                application.state.seed_session_id = await _install_seed_session(
+                    http,
+                    application.state.session_store,
+                    active_settings,
+                )
+            try:
+                yield
+            finally:
+                await anthropic_client.close()
 
     app = FastAPI(
         title="discovery-by-llm",
@@ -42,12 +76,14 @@ def create_app(
         redoc_url=None,
         lifespan=lifespan,
     )
+    app.add_middleware(RequestTimingMiddleware)
 
     @app.get("/api/health")
     def health() -> dict[str, str]:
         return {"status": "ok", "mode": active_settings.app_mode}
 
     app.include_router(router)
+    app.include_router(recommendations_router)
     if FRONTEND_DIST.is_dir():
         app.mount("/", StaticFiles(directory=FRONTEND_DIST, html=True), name="spa")
 
@@ -55,3 +91,41 @@ def create_app(
 
 
 app = create_app()
+
+
+def _validate_live_settings(application_settings: Settings) -> None:
+    if application_settings.app_mode is not AppMode.LIVE:
+        return
+    if not application_settings.spotify_client_id:
+        raise RuntimeError("SPOTIFY_CLIENT_ID is required in live mode")
+    if not application_settings.anthropic_api_key:
+        raise RuntimeError("ANTHROPIC_API_KEY is required in live mode")
+
+
+async def _install_seed_session(
+    http: httpx2.AsyncClient,
+    session_store: SessionStore,
+    application_settings: Settings,
+) -> str:
+    tokens = await refresh_access_token(
+        http,
+        client_id=application_settings.spotify_client_id,
+        tokens=TokenSet(
+            access_token="seed-bootstrap",
+            refresh_token=application_settings.spotify_seed_refresh_token,
+            expires_at=0.0,
+        ),
+    )
+    bootstrap_session = SpotifySession(tokens=tokens, account_id="", display_name="")
+    current_user = await SpotifyClient(
+        http,
+        bootstrap_session,
+        application_settings,
+    ).fetch_current_user()
+    return session_store.create(
+        SpotifySession(
+            tokens=bootstrap_session.tokens,
+            account_id=current_user.account_id,
+            display_name=current_user.display_name,
+        )
+    )