fastapi-architect-mcp

An MCP server that gives Claude Code IDE-level intelligence for FastAPI projects — semantic code navigation, safe renaming, route inspection, dependency trees, and Pydantic model analysis.

Instead of Claude reading files blindly, it calls structured tools backed by Jedi (Python language server) and Python's AST.

Tools

Tool	Description
`find_references`	Find all usages of a symbol across the project
`rename_symbol`	Safely rename a symbol across all files
`go_to_definition`	Jump to where a symbol is defined
`get_completions`	Get completion suggestions at a cursor position
`list_routes`	List all FastAPI routes across the entire project
`get_dependencies`	Get the full `Depends()` injection tree for a handler
`build_dependency_graph`	Full graph: route → input models → dependencies → response model
`validate_response_models`	Detect routes missing a `response_model` declaration
`list_models`	List all Pydantic/SQLModel models in a file
`inspect_model`	Inspect a model's fields, types, defaults, and validators
`find_model_usages`	Find everywhere a model is used across the project
`detect_schema_orm_mismatches`	Detect field mismatches between ORM model and Pydantic schema

Installation

pip install fastapi-architect-mcp

Configuration

Option 1 — Global (available in all projects)

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "fastapi-architect": {
      "command": "fastapi-architect-mcp"
    }
  }
}

Option 2 — Per project (recommended for best results)

Create .mcp.json at your project root:

{
  "mcpServers": {
    "fastapi-architect": {
      "command": "/path/to/your/project/venv/bin/fastapi-architect-mcp"
    }
  }
}

Using your project's own venv gives Jedi access to all your project's dependencies, which enables full cross-file find_references and rename_symbol support.

Then restart Claude Code.

Usage examples

Once connected, you can ask Claude Code things like:

"List all routes in this project"
"What are the dependencies of the get_users handler?"
"Find all references to get_db across the project"
"Rename get_db to get_session everywhere"
"Inspect the UserCreate model"
"Are there any routes missing a response_model?"
"Show me the full dependency graph for the users router"
"Are there any mismatches between my User ORM model and UserPublic schema?"

Supported patterns

Dependency injection

def handler(x=Depends(func)) — standard FastAPI
def handler(*, x=Depends(func)) — keyword-only args
@router.get("/", dependencies=[Depends(func)]) — decorator-level deps
SessionDep = Annotated[Session, Depends(get_db)] — Annotated aliases (modern FastAPI)

Models

BaseModel — Pydantic
SQLModel — SQLModel
BaseSettings — Pydantic settings
RootModel — Pydantic v2
Inherited models (e.g. class UserCreate(UserBase))

Validators

@validator — Pydantic v1
@field_validator — Pydantic v2

Known limitations

find_references and rename_symbol work cross-file only when the MCP is configured to use the project's own venv (Option 2 above). With a global install, they only operate on the file where the symbol is defined.
get_dependencies supports native FastAPI Depends() only. Other DI frameworks (Dishka, dependency-injector, etc.) are not supported.
Runtime dependencies (middleware, lifespan events, startup hooks) are not visible to static analysis and won't appear in dependency trees.
get_completions is most useful at attribute access positions (e.g. after a .). On empty lines it returns all Python builtins.

Requirements

Python 3.11+
Claude Code (VS Code extension or CLI)

Author

Abdessamad Touzani

GitHub: @AbdessamadTzn
LinkedIn: abdessamadtouzani