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

# Sources

> Give your agents context with documents, files, and web links

## What Are Sources?

Sources are documents and files that give your agent the context it needs to do its job. Think of them as the reference materials you'd hand a new team member — price lists, SOPs, contracts, policies, or any document your agent needs to reason over.

<Card title="How It Works" icon="brain">
  When you upload a source, Decisional indexes it using **Retrieval-Augmented Generation (RAG)**. Your agent can then search and retrieve relevant information from your documents at runtime.
</Card>

## Supported File Types

<CardGroup cols={3}>
  <Card title="PDFs" icon="file-pdf">
    Contracts, invoices, forms, reports, SOPs (up to 50MB, OCR supported)
  </Card>

  <Card title="Documents" icon="file-word">
    Policies, templates, procedures (Word, PowerPoint)
  </Card>

  <Card title="Images" icon="image">
    Receipts, forms, diagrams (PNG, JPG, TIFF up to 20MB with OCR)
  </Card>

  <Card title="Text Files" icon="file-lines">
    Code, configs, raw text, JSON, XML
  </Card>
</CardGroup>

## Adding Sources

<Steps>
  <Step title="Open the Sources Tab">
    In your agent page, click **Sources** in the left sidebar.
  </Step>

  <Step title="Upload Files or Add Links">
    Click **Add Source** and choose:

    * **Upload File** — drag and drop files (up to 50MB each)
    * **Add Link** — paste a URL and Decisional will fetch and index the content
  </Step>

  <Step title="Wait for Processing">
    Decisional indexes your source (usually 10 seconds to 3 minutes depending on size). Once indexed, your agent can use it.
  </Step>

  <Step title="Reference in Instructions">
    Tell your agent when to use specific sources:

    ```
    Reference the "Q4 Price List.pdf" for current pricing.
    Use the "Vendor Catalog.xlsx" to validate vendor names.
    ```
  </Step>
</Steps>

## How RAG Works

When your agent runs, it doesn't read every document end to end. Instead, it uses RAG to find the most relevant sections:

1. **Indexing** — your documents are chunked and semantically indexed when uploaded
2. **Retrieval** — at runtime, the agent searches for sections relevant to the current task
3. **Generation** — the agent uses the retrieved context to reason and produce output
4. **Citation** — the agent cites the specific pages and sections it referenced

## Bounding Box Citations

For PDFs, Decisional shows you the **exact location** the agent read — including the page number, paragraph, and a highlighted bounding box around the text. This makes it easy to verify your agent's reasoning.

## Tips for Better Source Quality

* **Use text-based PDFs** — scanned images work (via OCR) but text-based PDFs are faster and more accurate
* **Remove irrelevant pages** — cover pages, blank pages, and appendices add noise
* **Use clear formatting** — documents with headers and sections are easier for agents to navigate
* **Keep documents focused** — one topic per file works better than large catch-all documents
* **Use descriptive filenames** — "Q4 2025 Price List" is better than "pricelist\_final\_v3.xlsx"
* **10-20 sources is the sweet spot** — too many sources can slow retrieval

<Tip>
  Start with fewer, high-quality sources and add more as needed. Quality beats quantity.
</Tip>