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Chart Creation

Use X21 to generate charts without leaving the chat. Claude can analyse a dataset, select an appropriate visual, and request the create_chart tool to build it directly inside Excel.

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create_chart Tool Overview

  • Inputs
    • workbookName, worksheet
    • chartType – e.g., ColumnClustered, Line, Pie, BarStacked.
    • sourceData – Range containing the data (e.g., A1:C20).
    • Optional metadata: chart title, axis labels, series names, chart position (top, left, width, height).
  • The Excel API adds a chart object to the specified worksheet, positions it relative to the top-left cell of the destination range, and returns coordinates for verification.

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Typical Workflow

  1. Ask Claude to analyse the current selection and recommend a chart.
  2. Review the proposed chart data and configuration in the chat response.
  3. Approve the create_chart tool request. Use View to preview and adjust before final approval.
  4. After creation, Claude can suggest follow-up formatting (e.g., colour changes via write_format on chart elements).

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Customisation Tips

  • Encourage Claude to name series explicitly. The tool accepts a series array so legends stay meaningful even when column headers are ambiguous.
  • Use read_values to verify the data range before charting—especially when data contains blanks or totals that should be excluded.
  • Charts respect existing theme colours. For custom palettes, instruct Claude to apply formatting via subsequent tool calls.

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Supported Chart Types

The default implementation covers the most common Excel charts:
  • Clustered and stacked column/ bar charts.
  • Line and area charts (single or multi-series).
  • Pie and doughnut charts.
  • Scatter plots (using X/Y ranges).
Extend HandleCreateChart in the Excel API to add specialised types like combo charts or waterfall visualisations.

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Troubleshooting

  • If the chart appears off-screen, adjust the position parameters or ask Claude to move it using write_format on the chart object.
  • Invalid ranges or non-numeric data trigger errors returned to the UI. Review the range and ensure it contains headers + numeric series.
  • Charts created on protected sheets require the sheet to be unlocked first.
By combining chart creation with Claude’s descriptive explanations, you can produce polished visuals faster than manual Excel workflows.