---
title: uv
sidebarTitle: uv
---
# `fastmcp.utilities.mcp_server_config.v1.environments.uv`
## Classes
### `UVEnvironment`
Configuration for Python environment setup.
**Methods:**
#### `build_command`
```python
build_command(self, command: list[str]) -> list[str]
```
Build complete uv run command with environment args and command to execute.
**Args:**
- `command`: Command to execute (e.g., ["fastmcp", "run", "server.py"])
**Returns:**
- Complete command ready for subprocess.run, including "uv" prefix if needed.
- If no environment configuration is set, returns the command unchanged.
#### `run_with_uv`
```python
run_with_uv(self, command: list[str]) -> None
```
Execute a command using uv run with this environment configuration.
**Args:**
- `command`: Command and arguments to execute (e.g., ["fastmcp", "run", "server.py"])
#### `needs_uv`
```python
needs_uv(self) -> bool
```
Deprecated: Use _needs_setup() internally or check if build_command modifies the command.
#### `build_uv_run_command`
```python
build_uv_run_command(self, command: list[str]) -> list[str]
```
Deprecated: Use build_command() instead.
#### `prepare`
```python
prepare(self, output_dir: Path | None = None) -> None
```
Prepare the Python environment using uv.
**Args:**
- `output_dir`: Directory where the persistent uv project will be created.
If None, creates a temporary directory for ephemeral use.