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

# Working with Existing Models

> Learn how to upload, audit, and work with your existing spreadsheets

Apers can read, understand, and improve spreadsheets you already have.

## Uploading Your Models

<Steps>
  <Step title="Open the Data Room">
    The Data Room is on the right side of your screen.
  </Step>

  <Step title="Drag and drop your file">
    Drop your Excel file into the Data Room.
  </Step>

  <Step title="Wait for processing">
    Apers will read and understand the structure and logic of your model automatically.
  </Step>
</Steps>

## What Apers Understands

When you upload a model, Apers learns:

* The overall structure
* How formulas connect to each other
* The logic behind calculations
* Sub-models and their relationships

This means you can ask questions or make changes without explaining everything from scratch.

## Checking for Errors

Apers can audit your models to find mistakes.

**Example instructions:**

* "Check this model for formula errors"
* "Find any broken links in this spreadsheet"
* "Audit this proforma for calculation mistakes"

<Info>
  This is useful for models your firm created in the past. Apers helps make sure they're error-tight before you use them again.
</Info>

## Asking Questions About Your Model

Once uploaded, you can ask Apers anything about the spreadsheet:

* "How is the IRR calculated?"
* "What assumptions drive the cash flow?"
* "Explain the debt schedule"

Apers will answer based on what it learned from your file.