---
type: operations
title: Configuration and data files
description: How src/config.rs loads config.toml, the supported keys and defaults, where the data directory and databases live, and operational and security caveats.
tags: [configuration, toml, data-directory, sqlite, security]
verified:
  - by: openwiki/0.7.2
    at: 2026-10-19T18:58:46.219Z
sources:
  - id: openwiki-source-ea70eb6c045047448e446296
    resource: repo://.gitignore
  - id: openwiki-source-2a737474d86fc75cc9d9694f
    resource: repo://src/config.rs
generated: { by: "claude-code", at: "2026-10-19T18:58:46.219Z" }
---

# Configuration and data files

All runtime settings come from one TOML file loaded by `Config::load`
(`src/config.rs:188-192`). No environment variable is ever read
(`src/config.rs:1-13`).

## Data directory

The data directory is fixed: `<platform config dir>/wh`, resolved with
`dirs::config_dir()` (`src/config.rs:106-110`). On Windows this is
`%APPDATA%\wh`. It cannot be changed from the config file. At startup
`ensure_data_dir` creates it if missing (`src/config.rs:214-217`).

| File | Purpose | Defined by |
|---|---|---|
| `config.toml` | Optional settings | `CONFIG_FILE`, `src/config.rs:34` |
| `session.db` | WhatsApp session store used by `whatsapp-rust` ([WhatsApp client](../integrations/whatsapp-client.md)) | `session_db_path`, `src/config.rs:223-225` |
| `history.db` | Local messages, chats, contacts and autoreply flags ([History store](../concepts/history-store.md)) | `history_db_path`, `src/config.rs:231-233` |

## Keys

| Key | Purpose | Default when missing or blank |
|---|---|---|
| `openai_api_key` | Bearer token for the AI endpoint (trimmed) | none — the [AI client](../integrations/ai-client.md) cannot be built |
| `openai_base_url` | Base URL of the OpenAI-compatible endpoint (trimmed, trailing `/` removed) | `https://ollama.com/v1` |
| `openai_model` | Model for text replies (trimmed) | `deepseek-v4.1-flash` |
| `openai_vision_model` | Model for image replies (trimmed) | none — image understanding disabled |
| `system_prompt` | Persona/instructions for autoreplies, kept as written (not trimmed, multiline allowed) | none — AI not configured |

Mapping and defaults: `src/config.rs:198-208`, `src/config.rs:23-25`.
The binary embeds no prompt text: without `system_prompt` the AI is not
configured and the status line says so (see
[Application state](../architecture/app-state.md)). Unknown keys are ignored.

## Loading rules

- Missing file → all defaults (`src/config.rs:142-152`).
- Unreadable file → `cannot read config file <path>`.
- Invalid TOML or wrong value type → `invalid config file <path>` with the
  cause `invalid TOML syntax or value type at line L, column C`; the error
  never echoes file content (`src/config.rs:127-136`).
- A leading UTF-8 BOM (common with Windows editors) and CRLF line endings
  are tolerated.
- `openai_base_url` consisting only of slashes is rejected with
  `openai_base_url in config.toml must not be empty or only slashes`
  (`src/config.rs:174-181`).

Startup aborts with `cannot load configuration` on any of these errors
([Runtime](../architecture/runtime-and-event-loop.md)).

## Security and operational notes

- The API key is never printed: `Config`'s `Debug` shows `***` or `<unset>`
  (`src/config.rs:80-100`), and the raw `FileConfig` has no `Debug` impl at
  all (`src/config.rs:64-78`). The AI client redacts it too.
- Keep `config.toml` in the data directory, outside the repository.
  `.gitignore` ignores a root-level `/config.toml` and `.env`
  (`.gitignore:4-6`), as well as SQLite journal/WAL/SHM files; note that the
  `*.db` pattern is commented out (`.gitignore:7`), so databases copied into
  the repo would not be ignored.
- `session.db` holds the linked-device credentials: deleting it forces a new
  QR pairing. `history.db` can be deleted to reset local history and
  autoreply flags; it is recreated on start.
- Images downloaded for vision replies are kept in memory only and never
  written to the data directory.

## Tests

`src/config.rs:236+` covers defaults, full files, blank values, multiline
prompts, trimming, base URL normalisation and errors, `Debug` masking,
vision model, DB paths, unknown keys, BOM/CRLF, non-leaking parse errors,
missing, existing, invalid and unreadable files. See
[Unit tests](../testing/unit-tests.md).