✨ Add support for reading configuration from pyproject.toml

Author: patrick91

pyproject.toml

@@ -35,6 +35,7 @@ dependencies = [
     "typer >= 0.15.1",
     "uvicorn[standard] >= 0.15.0",
     "rich-toolkit >= 0.14.8",
+    "tomli >= 2.0.0; python_version < '3.11'"
 ]
 
 [project.optional-dependencies]

src/fastapi_cli/cli.py

@@ -3,10 +3,12 @@
 from typing import Any, List, Union
 
 import typer
+from pydantic import ValidationError
 from rich import print
 from rich.tree import Tree
 from typing_extensions import Annotated
 
+from fastapi_cli.config import FastAPIConfig
 from fastapi_cli.discover import get_import_data, get_import_data_from_import_string
 from fastapi_cli.exceptions import FastAPICLIException
 
@@ -111,11 +113,41 @@ def _run(
             "Searching for package file structure from directories with [blue]__init__.py[/blue] files"
         )
 
+        if entrypoint and (path or app):
+            toolkit.print_line()
+            toolkit.print(
+                "[error]Cannot use --entrypoint together with path or --app arguments"
+            )
+            toolkit.print_line()
+            raise typer.Exit(code=1)
+
         try:
-            if entrypoint:
-                import_data = get_import_data_from_import_string(entrypoint)
-            else:
+            config = FastAPIConfig.resolve(
+                host=host,
+                port=port,
+                entrypoint=entrypoint,
+            )
+        except ValidationError as e:
+            toolkit.print_line()
+            toolkit.print("[error]Invalid configuration in pyproject.toml:")
+            toolkit.print_line()
+
+            for error in e.errors():
+                field = ".".join(str(loc) for loc in error["loc"])
+                toolkit.print(f"  [red]•[/red] {field}: {error['msg']}")
+
+            toolkit.print_line()
+
+            raise typer.Exit(code=1) from None
+
+        try:
+            # Resolve import data with priority: CLI path/app > config entrypoint > auto-discovery
+            if path or app:
                 import_data = get_import_data(path=path, app_name=app)
+            elif config.entrypoint:
+                import_data = get_import_data_from_import_string(config.entrypoint)
+            else:
+                import_data = get_import_data()
         except FastAPICLIException as e:
             toolkit.print_line()
             toolkit.print(f"[error]{e}")
@@ -151,7 +183,7 @@ def _run(
             tag="app",
         )
 
-        url = f"http://{host}:{port}"
+        url = f"http://{config.host}:{config.port}"
         url_docs = f"{url}/docs"
 
         toolkit.print_line()
@@ -179,8 +211,8 @@ def _run(
 
         uvicorn.run(
             app=import_string,
-            host=host,
-            port=port,
+            host=config.host,
+            port=config.port,
             reload=reload,
             workers=workers,
             root_path=root_path,

src/fastapi_cli/config.py

@@ -0,0 +1,53 @@
+import logging
+from pathlib import Path
+from typing import Any, Dict, Optional
+
+from pydantic import BaseModel
+
+logger = logging.getLogger(__name__)
+
+
+class FastAPIConfig(BaseModel):
+    entrypoint: Optional[str] = None
+    host: str = "127.0.0.1"
+    port: int = 8000
+
+    @classmethod
+    def _read_pyproject_toml(cls) -> Dict[str, Any]:
+        """Read FastAPI configuration from pyproject.toml in current directory."""
+        pyproject_path = Path.cwd() / "pyproject.toml"
+
+        if not pyproject_path.exists():
+            return {}
+
+        try:
+            import tomllib  # type: ignore[import-not-found]
+        except ImportError:
+            try:
+                import tomli as tomllib  # type: ignore[no-redef, import-not-found]
+            except ImportError:
+                logger.debug("tomli not available, skipping pyproject.toml")
+                return {}
+
+        with open(pyproject_path, "rb") as f:
+            data = tomllib.load(f)
+
+            return data.get("tool", {}).get("fastapi", {})  # type: ignore
+
+    @classmethod
+    def resolve(
+        cls,
+        host: Optional[str] = None,
+        port: Optional[int] = None,
+        entrypoint: Optional[str] = None,
+    ) -> "FastAPIConfig":
+        config = cls._read_pyproject_toml()
+
+        if host is not None:
+            config["host"] = host
+        if port is not None:
+            config["port"] = port
+        if entrypoint is not None:
+            config["entrypoint"] = entrypoint
+
+        return FastAPIConfig.model_validate(config)

tests/assets/pyproject_config/another_module.py

@@ -0,0 +1,8 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def read_root():
+    return {"Hello": "World"}

tests/assets/pyproject_config/my_module.py

@@ -0,0 +1,8 @@
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/")
+def read_root():
+    return {"Hello": "World"}

tests/assets/pyproject_config/pyproject.toml

@@ -0,0 +1,2 @@
+[tool.fastapi]
+entrypoint = "my_module:app"

tests/test_cli.py

@@ -189,6 +189,23 @@ def test_dev_env_vars_and_args() -> None:
         )
 
 
+def test_entrypoint_mutually_exclusive_with_path() -> None:
+    result = runner.invoke(app, ["dev", "mymodule.py", "--entrypoint", "other:app"])
+
+    assert result.exit_code == 1
+    assert (
+        "Cannot use --entrypoint together with path or --app arguments" in result.output
+    )
+
+
+def test_entrypoint_mutually_exclusive_with_app() -> None:
+    result = runner.invoke(app, ["dev", "--app", "myapp", "--entrypoint", "other:app"])
+    assert result.exit_code == 1
+    assert (
+        "Cannot use --entrypoint together with path or --app arguments" in result.output
+    )
+
+
 def test_run() -> None:
     with changing_dir(assets_path):
         with patch.object(uvicorn, "run") as mock_run:

tests/test_cli_pyproject.py

@@ -0,0 +1,97 @@
+from pathlib import Path
+from unittest.mock import patch
+
+import uvicorn
+from typer.testing import CliRunner
+
+from fastapi_cli.cli import app
+from tests.utils import changing_dir
+
+runner = CliRunner()
+
+assets_path = Path(__file__).parent / "assets"
+
+
+def test_dev_with_pyproject_app_config_uses() -> None:
+    with changing_dir(assets_path / "pyproject_config"), patch.object(
+        uvicorn, "run"
+    ) as mock_run:
+        result = runner.invoke(app, ["dev"])
+        assert result.exit_code == 0, result.output
+
+        assert mock_run.call_args.kwargs["app"] == "my_module:app"
+        assert mock_run.call_args.kwargs["host"] == "127.0.0.1"
+        assert mock_run.call_args.kwargs["port"] == 8000
+        assert mock_run.call_args.kwargs["reload"] is True
+
+        assert "Using import string: my_module:app" in result.output
+
+
+def test_run_with_pyproject_app_config() -> None:
+    with changing_dir(assets_path / "pyproject_config"), patch.object(
+        uvicorn, "run"
+    ) as mock_run:
+        result = runner.invoke(app, ["run"])
+        assert result.exit_code == 0, result.output
+
+        assert mock_run.call_args.kwargs["app"] == "my_module:app"
+        assert mock_run.call_args.kwargs["host"] == "0.0.0.0"
+        assert mock_run.call_args.kwargs["port"] == 8000
+        assert mock_run.call_args.kwargs["reload"] is False
+
+        assert "Using import string: my_module:app" in result.output
+
+
+def test_cli_arg_overrides_pyproject_config() -> None:
+    with changing_dir(assets_path / "pyproject_config"), patch.object(
+        uvicorn, "run"
+    ) as mock_run:
+        result = runner.invoke(app, ["dev", "another_module.py"])
+
+        assert result.exit_code == 0, result.output
+
+        assert mock_run.call_args.kwargs["app"] == "another_module:app"
+
+
+def test_pyproject_app_config_invalid_format() -> None:
+    test_dir = assets_path / "pyproject_invalid_config"
+    test_dir.mkdir(exist_ok=True)
+
+    pyproject_file = test_dir / "pyproject.toml"
+    pyproject_file.write_text("""
+[tool.fastapi]
+entrypoint = "invalid_format_without_colon"
+""")
+
+    try:
+        with changing_dir(test_dir):
+            result = runner.invoke(app, ["dev"])
+            assert result.exit_code == 1
+            assert (
+                "Import string must be in the format module.submodule:app_name"
+                in result.output
+            )
+    finally:
+        pyproject_file.unlink()
+        test_dir.rmdir()
+
+
+def test_pyproject_validation_error() -> None:
+    test_dir = assets_path / "pyproject_validation_error"
+    test_dir.mkdir(exist_ok=True)
+
+    pyproject_file = test_dir / "pyproject.toml"
+    pyproject_file.write_text("""
+[tool.fastapi]
+entrypoint = 123
+""")
+
+    try:
+        with changing_dir(test_dir):
+            result = runner.invoke(app, ["dev"])
+            assert result.exit_code == 1
+            assert "Invalid configuration in pyproject.toml:" in result.output
+            assert "entrypoint" in result.output.lower()
+    finally:
+        pyproject_file.unlink()
+        test_dir.rmdir()