diff --git a/backend/state.json b/backend/state.json
new file mode 100644
index 0000000..364b047
--- /dev/null
+++ b/backend/state.json
@@ -0,0 +1,87 @@
+{
+  "project_summary": "MTG Online Backend API with PostgreSQL database. Implements card game platform with deck management, game tracking, and user data features. Uses FastAPI, SQLAlchemy async, and Alembic for database migrations.",
+  "roadmap": [
+    {
+      "phase": 1,
+      "status": "completed",
+      "description": "Core application setup with FastAPI, database models, and basic endpoints",
+      "key_deliverables": ["FastAPI app", "Database models", "Authentication", "Deck management"]
+    },
+    {
+      "phase": 2,
+      "status": "completed",
+      "description": "User data schema implementation with Alembic migrations",
+      "key_deliverables": ["Alembic configuration", "Async migration environment", "Initial migration script", "User data models (16 tables)", "Updated Dockerfile", "Migration test plan"]
+    },
+    {
+      "phase": 3,
+      "status": "completed",
+      "description": "API endpoints for user data features",
+      "key_deliverables": ["User data routers", "Replay endpoints", "Card collection endpoints", "Group management endpoints", "Network endpoints", "Preferences endpoints", "Activity log endpoints"]
+    },
+    {
+      "phase": 4,
+      "status": "pending",
+      "description": "Testing and deployment",
+      "key_deliverables": ["Migration tests", "API tests", "Docker deployment", "Integration tests"]
+    }
+  ],
+  "tech_stack": {
+    "languages": ["Python 3.12"],
+    "frameworks": ["FastAPI", "SQLAlchemy (async)", "Alembic"],
+    "database": ["PostgreSQL"],
+    "dependencies": [
+      "fastapi==0.115.0",
+      "uvicorn[standard]==0.30.0",
+      "sqlalchemy[asyncio]==2.0.34",
+      "asyncpg==0.29.0",
+      "alembic==1.13.2",
+      "python-jose[cryptography]==3.3.0",
+      "passlib[bcrypt]==1.7.4",
+      "bcrypt==4.0.1",
+      "pydantic==2.9.2",
+      "pydantic-settings==2.5.2",
+      "redis[hiredis]==5.1.0"
+    ]
+  },
+  "architectural_notes": "Dual database setup: mtgonline for app data, mtgdata for MTGJSON card data. Alembic migrations run on container startup. Async SQLAlchemy with asyncpg driver. Card mirrors in mtgo_platform for fast deckbuilding queries. User data API mounted at /api/v1/user-data.",
+  "task_description": "Create Alembic migration setup for user data schema and complete API endpoints for all user data features",
+  "current_step": "Phase 3 completed - All API endpoints created with comprehensive documentation",
+  "files_created": [
+    "alembic.ini",
+    "alembic/env.py",
+    "alembic/versions/001_initial_user_schema.py",
+    "alembic/versions/__init__.py",
+    "app/models/user_data.py",
+    "scripts/run_migrations.sh",
+    "TEST_PLAN.md",
+    "app/schemas/user_data_schemas.py",
+    "app/routers/user_data.py",
+    "API_DOCUMENTATION.md"
+  ],
+  "files_modified": [
+    "app/models/__init__.py",
+    "Dockerfile",
+    "app/main.py"
+  ],
+  "decisions": [
+    "Using Alembic for version-controlled database migrations",
+    "Async Alembic configuration with run_sync for database operations",
+    "JSONB columns for flexible data storage (replay_data, activity_data)",
+    "CASCADE deletes for data integrity in related tables",
+    "Composite unique constraints for card collection uniqueness",
+    "RESTful API design with pagination support",
+    "JWT authentication for all endpoints",
+    "Permission checks for group/network management"
+  ],
+  "next_steps": [
+    "Test migration execution in container",
+    "Run API tests against all endpoints",
+    "Add rate limiting for production",
+    "Create integration tests",
+    "Deploy to staging environment"
+  ],
+  "blockers": [],
+  "commit_hash": "c42d7ca",
+  "timestamp": "2026-07-22T23:23:00-04:00"
+}