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Quick Start Guide

Get productive with X21 in minutes. This walkthrough assumes X21 is installed and the backend services are running (see Installation if you still need to set that up).

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1. Open the Copilot Task Pane

  • Launch Excel and create or open a workbook.
  • Navigate to the X21 ribbon and click Open Copilot. The WebView2 task pane loads the React UI.
  • Confirm the status indicator shows Connected. If not, click Reconnect to re-establish the WebSocket connection to the local Deno server.

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2. Sign In

  • Use the Supabase-powered login form in the pane. You can authenticate with email + magic link or SSO if configured.
  • After authentication, X21 stores the refreshed session token in WebView local storage. The backend immediately requests your email via user:email_request and caches it for Langfuse traces.

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3. Select Your Workbook Context

  • X21 automatically reads the active workbook name, selected range, sheet list, and used range through the VSTO ExcelSelection service.
  • If you want to focus on a specific area, select the relevant cells before prompting. The metadata is sent with each request so Claude can tailor its reasoning.

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4. Send Your First Prompt

Enter a natural language request such as: 
Summarize the revenue by region for the currently selected table and highlight the top three rows.
Choose the tools you want to make available (defaults include read_values, read_format, and write_values). Attach supporting PDFs or images if needed; the UI will encode them as base64 and the backend will inject them into the Claude conversation as document or image blocks. Click Send. The UI:
  1. Opens a WebSocket (stream:start).
  2. Streams Claude’s response (stream:delta) as it arrives.
  3. Emits tool:permission events whenever the LLM proposes a tool call.

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5. Review and Approve Tool Calls

  • Incoming tool requests appear in the Pending Actions list with a summary, arguments, and the target range.
  • Use View to stage the change via tool:view, which runs the tool and applies results to Excel without committing them.
  • Choose Approve to commit the change, Reject to send feedback, or Revert to undo a previously applied tool (tool:revert).
  • Enable Auto-approve if you trust the tools, or click Approve All for batch approvals. The UI automatically sends grouped responses with tool:permission:response.

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6. Inspect Results

  • Approved tool executions update the worksheet in place. X21 stores both old and new values (write_values returns before/after snapshots) so you can roll back if necessary.
  • Claude continues the conversation after each approval, referencing intermediate results.
  • Provide a thumbs up/down or leave feedback; the backend forwards it to Langfuse via score:score and score:feedback.

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