graph-excel-mcp

MCP server for reading and editing Excel workbooks on SharePoint, OneDrive or Teams through Microsoft Graph, without a browser. It has no dependencies and needs Node 18 or later.

It is built for workbooks that several people edit at once:

• Every write starts as a dry run.

• Before writing, it checks the cells' current content against the version you read, so it won't overwrite someone else's edit.

• After writing, it reads the cells back to confirm the change.

Install

Claude Code / any MCP host (stdio):

claude mcp add --scope user graph-excel -- npx -y graph-excel-mcp

{ "mcpServers": { "graph-excel": { "command": "npx", "args": ["-y", "graph-excel-mcp"] } } }

Claude Desktop extension / Claude plugin (Cowork): clone the repo and run npm run pack. This builds build/graph-excel-mcp-<version>.mcpb and the plugin/ folder. The plugin folder contains the server and a graph-excel skill.

Related MCP server: excel-o365

Sign in

Call the login_status tool, or run npx graph-excel-mcp login, then enter the code it shows at https://login.microsoft.com/device. The refresh token is saved in ~/.graph-excel/token.json with mode 600. Set GRAPH_EXCEL_HOME to keep it somewhere else.

Sign-in uses the Microsoft Graph PowerShell public client with the delegated scope Files.ReadWrite.All, so you don't need to register an app. If your tenant blocks user consent, an admin has to approve that client once.

Workbook aliases

Instead of pasting the SharePoint URL every time, you can add aliases to ~/.graph-excel/workbooks.json (see workbooks.example.json). The resolve tool returns the driveId and itemId you need for an alias.

Tools

Notes

• Every call runs inside a workbook session. Sessionless calls on large workbooks can time out with a 504 even though the write was applied.

• Line breaks are sent as \n, which Excel stores as \r\n. If you write \r\n directly, the cell ends up with a stray _x000D_.

Release

Bump version in package.json, run npm run pack, commit, then push a matching tag:

git tag v0.3.1 && git push origin v0.3.1

The Publish workflow runs the tests, publishes to npm through trusted publishing (no token or OTP; provenance attached) and creates a GitHub release with the .mcpb attached.

License

MIT