> ## 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.

# Environment Variables

> Complete reference of environment variables for configuring typemux-cc

typemux-cc can be configured through environment variables. These can be set directly when running the binary, or persistently via the [config file](/configuration/config-file).

## Core Configuration

### TYPEMUX\_CC\_BACKEND

<ParamField path="TYPEMUX_CC_BACKEND" type="string" default="pyright">
  The LSP backend to use for type-checking.

  **Valid values:**

  * `pyright` - Microsoft's pyright type checker (default)
  * `ty` - Astral's experimental type checker (by the creators of uv)
  * `pyrefly` - Meta's experimental type checker

  **Example:**

  ```bash theme={null}
  export TYPEMUX_CC_BACKEND="ty"
  ```
</ParamField>

<Note>
  Make sure the corresponding backend binary is available in your PATH:

  * `pyright`: requires `pyright-langserver` command
  * `ty`: requires `ty` command
  * `pyrefly`: requires `pyrefly` command
</Note>

## Backend Pool Management

### TYPEMUX\_CC\_MAX\_BACKENDS

<ParamField path="TYPEMUX_CC_MAX_BACKENDS" type="integer" default="8">
  Maximum number of concurrent backend processes that can run simultaneously.

  Each virtual environment gets its own backend process. When the pool reaches this limit, the least recently used (LRU) backend will be evicted when a new one is needed.

  **Constraints:**

  * Minimum value: `1`
  * Recommended: `4-16` depending on available RAM

  **Example:**

  ```bash theme={null}
  export TYPEMUX_CC_MAX_BACKENDS="16"
  ```
</ParamField>

<Tip>
  For monorepos with many projects, increase this value to avoid frequent backend restarts. Each backend consumes 100-500MB of RAM depending on project size.
</Tip>

### TYPEMUX\_CC\_BACKEND\_TTL

<ParamField path="TYPEMUX_CC_BACKEND_TTL" type="integer" default="1800">
  Backend time-to-live in seconds. Idle backends are automatically evicted after this duration.

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

  **Special value:**

  * `0` - Disables TTL-based eviction (backends only evicted when pool is full)

  **Example:**

  ```bash theme={null}
  # 1 hour TTL
  export TYPEMUX_CC_BACKEND_TTL="3600"

  # Disable TTL eviction
  export TYPEMUX_CC_BACKEND_TTL="0"
  ```
</ParamField>

<Info>
  TTL helps reclaim memory from idle backends. Set to `0` if you frequently switch between many projects and want to avoid re-initialization delays.
</Info>

### TYPEMUX\_CC\_WARMUP\_TIMEOUT

<ParamField path="TYPEMUX_CC_WARMUP_TIMEOUT" type="integer" default="2">
  Warmup timeout in seconds. After spawning, backends need time to build their cross-file index.

  During warmup, index-dependent requests (definition, references, implementation, typeDefinition) are queued. The backend transitions to "ready" when either:

  1. The backend sends a `$/progress` end notification (index build complete)
  2. This timeout expires (fail-open: queued requests are sent anyway)

  **Default:** `2` (seconds)

  **Special value:**

  * `0` - Disables warmup entirely (all requests forwarded immediately)

  **Example:**

  ```bash theme={null}
  # Wait up to 5 seconds for index build
  export TYPEMUX_CC_WARMUP_TIMEOUT="5"

  # Disable warmup (forward all requests immediately)
  export TYPEMUX_CC_WARMUP_TIMEOUT="0"
  ```
</ParamField>

<Warning>
  Setting this to `0` may cause incomplete results for "find references" and "go to definition" requests immediately after backend spawn.
</Warning>

## Logging Configuration

### TYPEMUX\_CC\_LOG\_FILE

<ParamField path="TYPEMUX_CC_LOG_FILE" type="string" default="(not set)">
  Path to log file for persistent logging.

  **Default behavior:** Logs are written to stderr only

  **When set:** Logs are written to both stderr AND the specified file

  **Example:**

  ```bash theme={null}
  export TYPEMUX_CC_LOG_FILE="/tmp/typemux-cc.log"
  ```

  See [Logging](/configuration/logging) for monitoring and log analysis techniques.
</ParamField>

### RUST\_LOG

<ParamField path="RUST_LOG" type="string" default="typemux_cc=debug">
  Controls logging verbosity. Uses the `tracing` crate's env filter syntax.

  **Common values:**

  * `typemux_cc=info` - High-level events (venv switches, warmup transitions)
  * `typemux_cc=debug` - **Default**. Includes venv search details and LSP method names
  * `typemux_cc=trace` - Very verbose (all search steps, detailed debugging)

  **Example:**

  ```bash theme={null}
  # Minimal logging
  export RUST_LOG="typemux_cc=info"

  # Maximum verbosity
  export RUST_LOG="typemux_cc=trace"
  ```
</ParamField>

<Note>
  The log level affects all output (both stderr and file). Lower verbosity improves performance but provides less debugging information.
</Note>

## Setting Environment Variables

### Method 1: Direct Export (Temporary)

```bash theme={null}
export TYPEMUX_CC_BACKEND="ty"
export TYPEMUX_CC_LOG_FILE="/tmp/typemux-cc.log"
./target/release/typemux-cc
```

### Method 2: Inline (Single Execution)

```bash theme={null}
TYPEMUX_CC_BACKEND=ty TYPEMUX_CC_LOG_FILE=/tmp/typemux-cc.log ./target/release/typemux-cc
```

### Method 3: Config File (Persistent)

For persistent configuration across Claude Code restarts, use the config file:

```bash theme={null}
mkdir -p ~/.config/typemux-cc
cat > ~/.config/typemux-cc/config << 'EOF'
export TYPEMUX_CC_BACKEND="ty"
export TYPEMUX_CC_LOG_FILE="/tmp/typemux-cc.log"
export TYPEMUX_CC_MAX_BACKENDS="16"
export RUST_LOG="typemux_cc=debug"
EOF
```

See [Config File](/configuration/config-file) for more details.

## Precedence Rules

When multiple configuration methods are used:

1. **CLI flags** (e.g., `--backend ty`) - Highest priority
2. **Environment variables** - Middle priority
3. **Built-in defaults** - Lowest priority

<Info>
  CLI flags like `--backend`, `--max-backends`, `--backend-ttl`, and `--log-file` override the corresponding environment variables.
</Info>

## Quick Reference Table

| Variable                    | Type    | Default            | Description                               |
| --------------------------- | ------- | ------------------ | ----------------------------------------- |
| `TYPEMUX_CC_BACKEND`        | string  | `pyright`          | LSP backend to use (pyright, ty, pyrefly) |
| `TYPEMUX_CC_MAX_BACKENDS`   | integer | `8`                | Max concurrent backend processes (min: 1) |
| `TYPEMUX_CC_BACKEND_TTL`    | integer | `1800`             | Backend TTL in seconds (0 = disabled)     |
| `TYPEMUX_CC_WARMUP_TIMEOUT` | integer | `2`                | Warmup timeout in seconds (0 = disabled)  |
| `TYPEMUX_CC_LOG_FILE`       | string  | *(not set)*        | Log file path (stderr + file when set)    |
| `RUST_LOG`                  | string  | `typemux_cc=debug` | Log level (info, debug, trace)            |

## Related Pages

* [Config File](/configuration/config-file) - Persistent configuration for Claude Code plugin
* [Logging](/configuration/logging) - Log monitoring and analysis techniques