> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/K-dash/typemux-cc/llms.txt
> Use this file to discover all available pages before exploring further.

# CLI Flags

> Complete reference for all typemux-cc command-line flags

All CLI flags can be set via environment variables. CLI flags take precedence over environment variables.

## Core Flags

<ParamField path="--log-file" type="path" optional>
  Path to log file for debug output.

  When specified, logs are written to both stderr (default) and the specified file.

  **Environment variable**: `TYPEMUX_CC_LOG_FILE`

  **Default**: Not set (stderr only)

  **Example**:

  ```bash theme={null}
  typemux-cc --log-file /tmp/typemux-cc.log
  ```
</ParamField>

<ParamField path="--max-backends" type="integer" default="8">
  Maximum number of concurrent LSP backend processes.

  The proxy maintains a pool of backends (one per `.venv`). When the pool reaches this limit, the least recently used backend is evicted to make room for new ones.

  **Environment variable**: `TYPEMUX_CC_MAX_BACKENDS`

  **Valid range**: Minimum 1, no upper limit

  **Default**: `8`

  **Example**:

  ```bash theme={null}
  # Allow up to 16 concurrent backends for large monorepos
  typemux-cc --max-backends 16
  ```
</ParamField>

<ParamField path="--backend-ttl" type="integer" default="1800">
  Backend time-to-live (TTL) in seconds.

  Idle backends are automatically evicted after this timeout to free memory. Set to `0` to disable TTL eviction (backends only evicted via LRU when pool is full).

  **Environment variable**: `TYPEMUX_CC_BACKEND_TTL`

  **Default**: `1800` (30 minutes)

  **Example**:

  ```bash theme={null}
  # Keep backends alive for 1 hour
  typemux-cc --backend-ttl 3600

  # Disable TTL eviction entirely
  typemux-cc --backend-ttl 0
  ```
</ParamField>

<ParamField path="--backend" type="enum" default="pyright">
  LSP backend type to use for Python type checking.

  **Environment variable**: `TYPEMUX_CC_BACKEND`

  **Valid values**:

  * `pyright` - Microsoft's Pyright type checker (default)
  * `ty` - Google's ty type checker
  * `pyrefly` - Astral's pyrefly type checker

  **Default**: `pyright`

  **Example**:

  ```bash theme={null}
  # Use ty instead of pyright
  typemux-cc --backend ty
  ```
</ParamField>

## Usage Examples

### Basic Usage

```bash theme={null}
# Run with defaults (pyright, 8 max backends, 30min TTL)
typemux-cc
```

### Enable Logging

```bash theme={null}
# Log to file for debugging
typemux-cc --log-file /tmp/typemux-cc.log
```

### Large Monorepo Configuration

```bash theme={null}
# More backends, longer TTL, with logging
typemux-cc \
  --max-backends 20 \
  --backend-ttl 7200 \
  --log-file /var/log/typemux-cc.log
```

### Use Alternative Backend

```bash theme={null}
# Use ty backend instead of pyright
typemux-cc --backend ty
```

### Combine Multiple Flags

```bash theme={null}
# Complete configuration example
typemux-cc \
  --backend ty \
  --max-backends 12 \
  --backend-ttl 3600 \
  --log-file ~/.local/state/typemux-cc.log
```

## Flag Precedence

When both CLI flags and environment variables are set:

1. **CLI flags take precedence** over environment variables
2. **Environment variables** are used if no CLI flag is provided
3. **Default values** are used if neither is set

**Example**:

```bash theme={null}
# CLI flag wins (uses ty, not pyright)
export TYPEMUX_CC_BACKEND=pyright
typemux-cc --backend ty  # Uses ty
```

## See Also

* [Environment Variables](/reference/environment-variables) - Alternative configuration method
* [Configuration](/configuration/environment-variables) - Detailed configuration strategies
* [Architecture](/advanced/architecture) - Backend pool management details