# Rust core

Active contributors: Douwe de Vries, vriesd

## Purpose

The Rust core owns QA Scribe's domain model, SQLite schema, service layer, attachment files, AI prompt/response handling, and generation persistence. It is implemented in `crates/qa-scribe-core` and imported by both the Tauri app and smoke harness.

## Directory layout

```text
crates/qa-scribe-core/src/
  ai/
  attachments/
  domain/
  generation/
  services/
  storage/
  lib.rs
```

## Key abstractions

| Name | File | Description |
| --- | --- | --- |
| `SessionService` | `crates/qa-scribe-core/src/services/session_service.rs` | Main service facade over `Database`. |
| `Database` | `crates/qa-scribe-core/src/storage/mod.rs` | SQLite connection, schema setup, and migration/version checks. |
| `QaScribeError` | `crates/qa-scribe-core/src/error.rs` | Core error type used by services and Tauri commands. |
| Domain DTOs | `crates/qa-scribe-core/src/domain/mod.rs` | Re-exports Session, Entry, Draft, Finding, Attachment, AI Run, and settings types. |
| `prepare_ai_action_generation` | `crates/qa-scribe-core/src/generation/workflow.rs` | Creates generation context and running AI Run before provider execution. |
| `finish_ai_action_generation` | `crates/qa-scribe-core/src/generation/workflow.rs` | Persists generated Draft, Finding, or note update after provider output. |

## How it works

```mermaid
graph TD
    Commands[Tauri commands] --> Service[SessionService]
    Service --> Database[Database]
    Database --> SQLite[(SQLite)]
    Service --> Attachments[attachments module]
    Service --> Generation[generation workflow]
    Generation --> AiRun[AI Run rows]
    Generation --> Drafts[Draft/Finding/Entry writes]
```

The service layer validates drafts and patches, enforces ownership inside a Session, and performs multi-row operations in transactions when needed. `crates/qa-scribe-core/src/storage/mod.rs` defines schema version 7 and the tables used by Sessions, Entries, Attachments, Findings, Evidence links, Generation contexts, AI Runs, Drafts, and App settings.

## Integration points

`src-tauri/src/settings.rs` wraps `SessionService` in app state. `crates/qa-scribe-app/src/main.rs` imports the same core for smoke testing. `frontend/src/bindings.ts` receives many core domain types through Specta registration in `src-tauri/src/specta_bindings.rs`.

## Entry points for modification

Start in `crates/qa-scribe-core/src/domain` for data shape changes, `crates/qa-scribe-core/src/services/session_service` for business rules, and `crates/qa-scribe-core/src/storage/mod.rs` for persistence changes.