# Output Contract

## Primary Files

Each rule generation task owns exactly one output folder:

```text
output/rules-{task_id}/
```

The folder should contain:

```text
rules-{task_id}.xlsx
rules-{task_id}.md
```

Task state remains under:

```text
output/tasks/{task_id}.json
```

## State Fields

Use these fields for task outputs:

- `output_dir`: task output directory.
- `output_file`: Excel file path, retained for compatibility.
- `markdown_file`: Markdown file path, retained for compatibility.
- `files.excel`: Excel file path.
- `files.markdown`: Markdown file path.
- `markdown_error`: Markdown write error string, or `null`.

## Error Handling

Excel is the primary generated artifact. If Excel writing succeeds but Markdown writing fails, keep the Excel file and record `markdown_error`.

Do not rerun `_write_excel([])` after a Markdown-only failure; that can overwrite a valid workbook.

## API Exposure

`POST /api/rules/generate` should return:

- `task_id`
- `status`
- `limit`
- `output_dir`
- `output_file`
- `markdown_file`
- `files`
- `started_at`

`GET /api/rules/status` returns the persisted state JSON.