# Sources

Upload documents, follow their indexing, index them again or delete them.

A source is one document your workspace answers from. Answers can cite only the passages of your own sources.

## Upload

Open **Sources** and drop files onto the upload area, or choose them. Each batch takes up to 10 files; extra files are left out and you're told.

| Format | Extensions |
|---|---|
| Markdown | `.md`, `.markdown`, `.mdx` |
| Plain text | `.txt` |
| HTML | `.html`, `.htm` |
| PDF | `.pdf` |
| Word | `.docx` |

A file can be up to 25 MB. Empty files and other extensions are refused before upload, with the reason.

From your own code, use the sources endpoints in the [API reference](https://lornos.dev/docs/api.md#upload). Each API source holds one file, and its upload URL is valid for 10 minutes.

## What indexing does

After upload, Lornos reads the file, converts PDF, Word and HTML to text, splits it into passages and indexes them for this workspace only. Each passage gets an ID that answers cite. Follow the progress in [Jobs](https://lornos.dev/docs/jobs.md).

If a format can't be read right now, the file is still stored and shows **Format not indexed yet** in Jobs, ready to index once the format can be read.

## Index again

To index a source again after a failure, or to rebuild its passages, use **Retry** or **Re-index** in Jobs, or `POST /api/v1/sources/{id}/reindex` from the API.

## Delete

Use **Delete**, then **Confirm delete**, next to the upload. Deleting a source removes the file and its passages, so no later answer can cite it. Any member of the workspace can upload, index and delete sources.