# mcp.policy.environment_values_from_env

- **Module:** mcp.policy
- **Package:** tmux-mcp
- **Language:** Rust
- **Kind:** function
- **Source:** https://github.com/libtmux/libtmux-rs/blob/f0e37052c232636b61d095817046e6bfc8f2ca40/crates/tmux-mcp/src/policy.rs#L67
- **Page:** https://libtmux.org/en/rs/latest/mcp/reference/mcp-policy-environment_values_from_env/

```
mcp.policy.environment_values_from_env() -> Result<BTreeSet<String>, SurfaceError>
```

Read [`ENVIRONMENT_VALUES_ENV`] before serving MCP.

# Errors

Returns an error for invalid UTF-8 or any error
[`parse_environment_values`] reports.