Mythos Docs

Connect Microsoft Excel to work with spreadsheets stored in OneDrive for Business or SharePoint. Mythos can read worksheets, tables, charts, and ranges, then help you build an app around that data.

With Ask before changes selected, Mythos requests approval before it updates or clears cells. With Always allow, it can make those changes without asking each time. It can also add table rows and columns, create tables and charts, and add, rename, or delete worksheets.

Excel is also included in Microsoft 365. Use that connection when you want Excel alongside Outlook, Teams, or other Microsoft services. Use the separate Microsoft Excel connection described here for published Excel forms.

Examples to build

Example	Prompt to try
Sales dashboard	“Build a dashboard from the Sales table in this workbook. Add month and region filters, and format revenue as currency.”
Registration form	“Build a registration form that adds each submission to the Registrations table in this Excel workbook. Require a name and email address.”
Inventory tool	“Read the Inventory worksheet and build a searchable list. Let authorized staff update quantities in the existing table.”
Forecast comparison	“Compare the Forecast and Actuals ranges in this workbook. Show the difference by month and highlight the largest gaps.”

Name the workbook, worksheet, table, or range you mean. A link to the workbook is more useful than a filename that several files share.

Connect Excel

What you need

A Microsoft work or school account with access to the workbook.
An existing .xlsx workbook stored in OneDrive for Business or SharePoint. Personal OneDrive is not supported.
Permission to make any changes your app needs. A workbook being visible to you does not necessarily mean you can edit it.

A workbook shared in Teams may be suitable because Teams stores shared files in SharePoint or OneDrive. The underlying file location and your permissions determine access.

Add your account

Open Connectors from the Mythos Dashboard and choose Microsoft Excel.
Enter a Display name that identifies the account or workbook purpose. If a connection already exists, select Add connection to open a new form.
Choose Private, Share with others, or Share with workspace for access within Mythos.
Select Connect Microsoft Excel, sign in to your work or school account, and review Microsoft’s consent screen.
Return to your project. Open Chat actions (+) → Project connectors, find the saved Excel connection, and select Use in this project.

Microsoft requires file write permissions for Excel access, including reads. If your organization requires administrator consent, complete that approval before continuing.

First, confirm the right workbook is available:

Open this workbook and show me the worksheet and table names. Do not change the workbook.

Then ask Mythos to build the feature. For a published form, specify the destination table and the fields each submission should populate. Review the completed form with a sample submission before collecting real responses.

Working with a workbook

Use an existing workbook as the starting point. This connection is not a file upload service and does not create a new workbook from a local spreadsheet.

For a form or growing list, an Excel table gives rows and columns stable names. Tell Mythos which table to use and how the app should handle empty fields, duplicates, and invalid values. Keep formulas and protected ranges out of fields visitors can edit.

Changes affect the connected workbook. A shared connection does not give app visitors independent access to your Microsoft account, and a public form should only expose the inputs and results you intend to share.

Manage the connection

Open Microsoft Excel in Connectors to review the saved account and its sharing. If the account’s permissions change or Microsoft asks you to sign in again, reconnect and check the workbook before relying on the app.

Use Unlink projects to remove a project’s access or Disconnect to remove the connection from Mythos. Disconnecting leaves the workbook in Microsoft. Revoke Microsoft’s application consent separately if you also want to remove the authorization from your account.