feat: add PostgreSQL and Valkey configuration with async support, enhance database management

.env.example

@@ -7,3 +7,9 @@ LLM_API_KEY=
 
 # Logfire observability (set your token to enable)
 LOGFIRE_TOKEN=
+
+# PostgreSQL (asyncpg connection string)
+DATABASE_URL=postgresql+asyncpg://agent_alpha:agent_alpha@localhost:5432/agent_alpha
+
+# Valkey / Redis
+VALKEY_URL=redis://localhost:6379/0

backend/app.py

@@ -10,6 +10,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from uvicorn.logging import DefaultFormatter
 
 from backend.core.config import Settings
+from backend.core.database import close_engine, close_valkey
 from backend.core.dependencies import get_agent_service
 from backend.routes.chat import router as chat_router
 from backend.routes.health import router as health_router
@@ -81,7 +82,9 @@ class AppBuilder:
 
         # Graceful teardown on shutdown.
         await agent_service.shutdown()
-        logger.info("Agent Alpha backend shuttingdown")
+        await close_valkey()
+        await close_engine()
+        logger.info("Agent Alpha backend shutting down")
 
 
 # ---------------------------------------------------------------------------

backend/core/config.py

@@ -25,6 +25,9 @@ class Settings(BaseSettings):
     llm_api_key: str = ""
     logfire_token: str = ""
 
+    database_url: str = "postgresql+asyncpg://agent_alpha:agent_alpha@localhost:5432/agent_alpha"
+    valkey_url: str = "redis://localhost:6379/0"
+
     # ── Factories ──────────────────────────────────────────────────────────
 
     @classmethod

backend/core/database.py

@@ -0,0 +1,77 @@
+"""Async SQLAlchemy engine & session factory for PostgreSQL, plus a Valkey client.
+
+Usage::
+
+    from backend.core.database import get_session, get_valkey
+
+    async with get_session() as session:
+        result = await session.execute(text("SELECT 1"))
+
+    valkey = await get_valkey()
+    await valkey.set("key", "value")
+"""
+
+from __future__ import annotations
+
+from typing import AsyncIterator
+
+from redis.asyncio import Redis
+from sqlalchemy.ext.asyncio import (
+    AsyncSession,
+    async_sessionmaker,
+    create_async_engine,
+)
+
+from backend.core.config import settings
+
+# ── PostgreSQL (SQLAlchemy async) ──────────────────────────────────────────
+
+_engine = create_async_engine(
+    settings.database_url,
+    pool_size=5,
+    max_overflow=10,
+    echo=False,
+)
+
+_session_factory = async_sessionmaker(
+    bind=_engine,
+    class_=AsyncSession,
+    expire_on_commit=False,
+)
+
+
+async def get_session() -> AsyncIterator[AsyncSession]:
+    """Yield an async SQLAlchemy session (for FastAPI dependency injection)."""
+    async with _session_factory() as session:
+        try:
+            yield session
+            await session.commit()
+        except Exception:
+            await session.rollback()
+            raise
+
+
+# ── Valkey (Redis-compatible) ─────────────────────────────────────────────
+
+_valkey: Redis | None = None
+
+
+async def get_valkey() -> Redis:
+    """Return a shared Valkey (Redis) async client connection."""
+    global _valkey
+    if _valkey is None:
+        _valkey = Redis.from_url(settings.valkey_url, decode_responses=True)
+    return _valkey
+
+
+async def close_valkey() -> None:
+    """Close the Valkey connection pool (call on shutdown)."""
+    global _valkey
+    if _valkey is not None:
+        await _valkey.aclose()
+        _valkey = None
+
+
+async def close_engine() -> None:
+    """Dispose the SQLAlchemy engine (call on shutdown)."""
+    await _engine.dispose()

docker-compose.yml

@@ -23,7 +23,14 @@ services:
     environment:
       - LLM_BASE_URL=${LLM_BASE_URL:-http://host.docker.internal:11434/v1}
       - LLM_MODEL=${LLM_MODEL:-llama}
+      - DATABASE_URL=${DATABASE_URL:-postgresql+asyncpg://agent_alpha:agent_alpha@postgres:5432/agent_alpha}
+      - VALKEY_URL=${VALKEY_URL:-redis://valkey:6379/0}
     restart: unless-stopped
+    depends_on:
+      postgres:
+        condition: service_healthy
+      valkey:
+        condition: service_healthy
     # Uncomment to use a local .env file instead of env vars:
     # env_file:
     #   - .env
@@ -42,6 +49,40 @@ services:
       - backend
     restart: unless-stopped
 
+  # ── PostgreSQL ──────────────────────────────────────────────────
+  postgres:
+    image: postgres:16-alpine
+    container_name: agent-alpha-postgres
+    ports:
+      - "5432:5432"
+    environment:
+      POSTGRES_USER: agent_alpha
+      POSTGRES_PASSWORD: agent_alpha
+      POSTGRES_DB: agent_alpha
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U agent_alpha -d agent_alpha"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    restart: unless-stopped
+
+  # ── Valkey (Redis-compatible) ──────────────────────────────────
+  valkey:
+    image: valkey/valkey:8-alpine
+    container_name: agent-alpha-valkey
+    ports:
+      - "6379:6379"
+    volumes:
+      - valkey_data:/data
+    healthcheck:
+      test: ["CMD", "valkey-cli", "ping"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    restart: unless-stopped
+
   # ── Ollama (optional — uncomment to run the LLM locally) ────────
   # ollama:
   #   image: ollama/ollama:latest
@@ -59,5 +100,7 @@ services:
   #             count: all
   #             capabilities: [gpu]
 
-# volumes:
+volumes:
+  postgres_data:
+  valkey_data:
 #   ollama_data:

pyproject.toml

@@ -16,4 +16,7 @@ dependencies = [
     "pydantic-ai-todo>=0.2.4",
     "pydantic-deep>=0.3.28",
     "uvicorn[standard]>=0.34.0",
+    "asyncpg>=0.30.0",
+    "redis[hiredis]>=5.2.0",
+    "sqlalchemy[asyncio]>=2.0.36",
 ]