> For the complete documentation index, see [llms.txt](https://evo-5.gitbook.io/evo/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://evo-5.gitbook.io/evo/configuration/environment-variables.md).

# Environment Variables

evo is configured primarily through environment variables, making it easy to customize behavior without modifying files.

## Storage

| Variable              | Default          | Description                            |
| --------------------- | ---------------- | -------------------------------------- |
| `EVO_DATA_DIR`        | Platform default | Directory for SQLite database and logs |
| `EVO_MEMORY_DATA_DIR` | —                | Legacy name, still supported           |

Default storage locations:

| Platform | Path                                    |
| -------- | --------------------------------------- |
| macOS    | `~/Library/Application Support/evo/`    |
| Linux    | `${XDG_DATA_HOME:-~/.local/share}/evo/` |
| Windows  | `%APPDATA%\evo\`                        |

## Model Configuration

| Variable              | Default        | Description                                   |
| --------------------- | -------------- | --------------------------------------------- |
| `EVO_PROVIDER`        | Varies by host | Harness provider for reflection/consolidation |
| `EVO_MODEL`           | Varies by host | Model for reflection/consolidation            |
| `EVO_MEMORY_PROVIDER` | —              | Legacy name, still supported                  |
| `EVO_MEMORY_MODEL`    | —              | Legacy name, still supported                  |

## Hook Configuration

These apply to Claude Code and Codex integrations:

### Core Behavior

| Variable           | Default | Description                                         |
| ------------------ | ------- | --------------------------------------------------- |
| `EVO_HOOK_REFLECT` | `1`     | Set `0` to recall only, never write memory          |
| `EVO_HOOK_IMPORT`  | `1`     | Set `0` to skip workspace import on session start   |
| `EVO_HOOK_NOTIFY`  | `1`     | Set `0` to remove the transcript system message     |
| `EVO_HOOK_DEBUG`   | unset   | Set `1` to log every recall, import, and reflection |
| `EVO_HOOK_DISABLE` | unset   | Set `1` to make the hook a no-op (recursion guard)  |
| `EVO_HOOK_HOST`    | auto    | Force `claude` or `codex` when auto-detection fails |

### Recall Settings

| Variable                | Default                                   | Description                            |
| ----------------------- | ----------------------------------------- | -------------------------------------- |
| `EVO_HOOK_RECALL_LIMIT` | `40`                                      | Maximum memories considered per recall |
| `EVO_HOOK_MAX_CHARS`    | `6000`                                    | Character budget for injected context  |
| `EVO_HOOK_MODEL`        | `claude-haiku-4-5-20251001` (Claude Code) | Model for reflection                   |

### Batch Distillation

| Variable                 | Default  | Description                                             |
| ------------------------ | -------- | ------------------------------------------------------- |
| `EVO_HOOK_BATCH_TURNS`   | `10`     | Turns to gather before distilling; `1` for turn-by-turn |
| `EVO_HOOK_BATCH_CHARS`   | `12000`  | Character threshold to trigger batch                    |
| `EVO_HOOK_BATCH_IDLE_MS` | `300000` | Idle time (5 min) after which next event settles batch  |

### Turn Trimming

Turns are trimmed before batching to fit memory budget:

| Variable                        | Default | Description                                 |
| ------------------------------- | ------- | ------------------------------------------- |
| `EVO_HOOK_TURN_USER_CHARS`      | `400`   | Characters kept from each user message      |
| `EVO_HOOK_TURN_ASSISTANT_CHARS` | `600`   | Characters kept from each assistant message |
| `EVO_HOOK_TURN_TOOLS`           | `20`    | Tool names kept per turn                    |

## Example Configuration

```bash
# Smaller batches for faster feedback
export EVO_HOOK_BATCH_TURNS=5

# More context in each turn
export EVO_HOOK_TURN_USER_CHARS=800
export EVO_HOOK_TURN_ASSISTANT_CHARS=1000

# Verbose logging for debugging
export EVO_HOOK_DEBUG=1

# Custom storage location
export EVO_DATA_DIR=/srv/agent-memory
```

## Precedence

When multiple sources provide the same setting:

1. Explicit runtime configuration (plugin config)
2. Environment variable
3. Legacy environment variable (if applicable)
4. Platform default


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