> ## Documentation Index
> Fetch the complete documentation index at: https://gofastmcp.com/llms.txt
> Use this file to discover all available pages before exploring further.
# state
# `fastmcp.cli.deploy.state`
Versioned JSON state helpers for the FastMCP CLI.
## Functions
### `state_lock`
```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
state_lock(directory: Path) -> Iterator[None]
```
Lock related CLI state changes across processes.
### `read_state`
```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
read_state(path: Path, model: type[ModelT]) -> ModelT | None
```
Read and validate a versioned JSON state file.
### `write_state`
```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
write_state(path: Path, data: dict[str, Any]) -> None
```
Write JSON through a restricted temporary file and atomic replacement.
### `remove_state`
```python theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
remove_state(path: Path) -> None
```
Remove a state file when it exists.
## Classes
### `StateFileError`
A CLI state file could not be read or written safely.