> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spaceduck.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Document Scanning

> Convert PDFs to markdown using Marker — upload via the chat UI and the assistant processes them automatically.

## What it does

Converts uploaded PDF documents into markdown text that the assistant can read and discuss. Uses [Marker](https://github.com/VikParuchuri/marker), an open-source PDF-to-markdown converter that handles complex layouts, tables, and OCR.

## Requirements

Install Marker separately (it's not bundled with Spaceduck):

```bash theme={null}
pip install marker-pdf   # requires Python 3.10+, PyTorch
```

When `marker_single` is on your PATH, the `marker_scan` tool is automatically registered at gateway startup.

<Note>
  Marker is GPL-3.0 with Open Rail model weight restrictions. Spaceduck never bundles Marker — it calls `marker_single` as an external process.
</Note>

## How to use it

1. Click the **paperclip** button in the chat UI (or drag and drop a PDF)
2. The file is uploaded to the gateway
3. Ask the assistant about the document — it automatically invokes `marker_scan`
4. The PDF is converted to markdown and the assistant can read and discuss it

## Configuration

| Setting          | Default            | Description                                 |
| ---------------- | ------------------ | ------------------------------------------- |
| `timeoutMs`      | 120,000 ms (2 min) | Subprocess timeout — large PDFs can be slow |
| `maxOutputChars` | 100,000            | Output truncation limit                     |
| `pageRange`      | All pages          | Convert specific pages only                 |
| `forceOcr`       | `false`            | Force OCR even on text PDFs                 |

Set `MARKER_USE_LLM=true` as an environment variable to enable LLM-assisted conversion for higher-quality output on complex documents.

## Troubleshooting

| Problem               | Cause                              | Fix                                                           |
| --------------------- | ---------------------------------- | ------------------------------------------------------------- |
| Tool not registered   | `marker_single` not on PATH        | Run `pip install marker-pdf` and restart the gateway          |
| Timeout on large PDFs | Default 2-minute timeout too short | Increase timeout or use `pageRange` to convert specific pages |
| Poor OCR quality      | Default OCR settings               | Try `forceOcr: true` or enable LLM-assisted conversion        |
| Upload rejected       | File isn't a valid PDF             | Spaceduck validates magic bytes — only real PDFs are accepted |