diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..2071d4e
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,34 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project
+
+**phoenixvc-dev-api** — Development API for the phoenixvc organization. Built with FastAPI.
+
+## Status: Integration Review Pending
+
+Needs analysis of where this fits between the templating repos (azure-project-template, azure-infrastructure), other APIs (ai-gateway, codeflow-engine), and how it serves the phoenixvc ecosystem (cognitive-mesh, PhoenixRooivalk, Mystira, etc.).
+
+## Tech Stack
+
+- **Backend**: Python, FastAPI
+- **Org**: phoenixvc
+- **Environment**: dev
+
+## Key Commands
+
+```bash
+pip install -r requirements.txt   # Install dependencies
+uvicorn main:app --reload         # Start dev server
+pytest                            # Run tests
+mypy .                            # Type check
+```
+
+## AgentKit Forge
+
+This project has not yet been onboarded to [AgentKit Forge](https://github.com/phoenixvc/agentkit-forge). To request onboarding, [create a ticket](https://github.com/phoenixvc/agentkit-forge/issues/new?title=Onboard+phoenixvc-dev-api-fastapi&labels=onboarding).
+
+## Baton Integration
+
+Baton is the shared task graph for cross-repo work. When the `baton` MCP server is available, agents should check for existing work with `task_check` at the start of meaningful tasks, create or claim visible work with `task_notify`/`log_agent_message`, update the task when significant new information becomes available, and log completion or blockers before handing off.
diff --git a/src/api-hexagonal/domain/entities/user.py b/src/api-hexagonal/domain/entities/user.py
index c2add8f..13e9a25 100644
--- a/src/api-hexagonal/domain/entities/user.py
+++ b/src/api-hexagonal/domain/entities/user.py
@@ -2,15 +2,17 @@
 from datetime import datetime
 from typing import Optional
 
+
 @dataclass
 class User:
     """User domain entity"""
+
     id: Optional[int]
     email: str
     name: str
     password_hash: str
     created_at: datetime
     updated_at: datetime
-    
+
     def is_valid_email(self) -> bool:
-        return '@' in self.email and '.' in self.email.split('@')[1]
+        return "@" in self.email and "." in self.email.split("@")[1]
diff --git a/src/api-hexagonal/domain/repositories/user_repository.py b/src/api-hexagonal/domain/repositories/user_repository.py
index 47c64df..03aa025 100644
--- a/src/api-hexagonal/domain/repositories/user_repository.py
+++ b/src/api-hexagonal/domain/repositories/user_repository.py
@@ -1,9 +1,12 @@
-from abc import ABC, abstractmethod
+from abc import ABC
 from typing import Optional
+
 from domain.entities.user import User
 
+
 class UserRepository(ABC):
     async def create(self, user: User) -> User:
         pass
+
     async def get_by_id(self, user_id: int) -> Optional[User]:
         pass
diff --git a/src/api-standard/main.py b/src/api-standard/main.py
index 7944b9f..01f9224 100644
--- a/src/api-standard/main.py
+++ b/src/api-standard/main.py
@@ -1,10 +1,13 @@
 from fastapi import FastAPI
+
 app = FastAPI()
 
-@app.get('/')
+
+@app.get("/")
 async def root():
-    return {'message': 'API Standard'}
+    return {"message": "API Standard"}
+
 
-@app.get('/health')
+@app.get("/health")
 async def health():
-    return {'status': 'healthy'}
+    return {"status": "healthy"}
diff --git a/tests/unit/test_user_entity.py b/tests/unit/test_user_entity.py
new file mode 100644
index 0000000..39686f3
--- /dev/null
+++ b/tests/unit/test_user_entity.py
@@ -0,0 +1,46 @@
+from datetime import datetime
+from importlib.util import module_from_spec, spec_from_file_location
+from pathlib import Path
+
+
+def load_user_class():
+    user_path = (
+        Path(__file__).parents[2]
+        / "src"
+        / "api-hexagonal"
+        / "domain"
+        / "entities"
+        / "user.py"
+    )
+    spec = spec_from_file_location("user_entity", user_path)
+    module = module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module.User
+
+
+def test_user_validates_email_shape():
+    User = load_user_class()
+    user = User(
+        id=1,
+        email="user@example.com",
+        name="Test User",
+        password_hash="hashed",
+        created_at=datetime(2026, 1, 1),
+        updated_at=datetime(2026, 1, 1),
+    )
+
+    assert user.is_valid_email()
+
+
+def test_user_rejects_email_without_domain_dot():
+    User = load_user_class()
+    user = User(
+        id=1,
+        email="user@example",
+        name="Test User",
+        password_hash="hashed",
+        created_at=datetime(2026, 1, 1),
+        updated_at=datetime(2026, 1, 1),
+    )
+
+    assert not user.is_valid_email()