@walterra/pi-charts

Vega-Lite chart extension for pi coding agent - render data visualizations as inline images

Package details

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extension

Install @walterra/pi-charts from npm and Pi will load the resources declared by the package manifest.

npm repohome report
$ pi install npm:@walterra/pi-charts
Package
@walterra/pi-charts
Version
0.0.5
Published
Mar 23, 2026
Downloads
4,169/mo · 326/wk
Author
walterra
License
MIT
Types
extension
Size
55 KB
Dependencies
1 dependency · 1 peer
Pi manifest JSON
{
  "extensions": [
    "./extensions/vega-chart/index.ts"
  ],
  "video": "https://www.rafelsberger.at/assets/pi-charts-sm-0003.mp4"
}

Security note

Pi packages can execute code and influence agent behavior. Review the source before installing third-party packages.

README

@walterra/pi-charts

Vega-Lite chart extension for pi coding agent - render data visualizations as inline terminal images.

Installation

pi install npm:@walterra/pi-charts

This installs the package globally and adds it to your pi settings.

Compatibility

  • Tested with pi 0.62.0

Features

  • Declarative Visualizations: Use Vega-Lite JSON specs to describe charts
  • Auto Dependencies: Python, altair, pandas, vl-convert auto-installed via uv
  • Inline Display: Charts render directly in terminals supporting inline images (Ghostty, Kitty, iTerm2, WezTerm)
  • Save to File: Optionally save charts to PNG files

Tool: vega_chart

Renders a Vega-Lite specification as a PNG image.

Parameters

Parameter Type Required Description
spec string ✅ Vega-Lite JSON specification
tsv_data string Optional TSV data to replace spec.data.values
width number Chart width in pixels (default: 600)
height number Chart height in pixels (default: 400)
save_path string Optional file path to save the PNG

Example

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "data": {
    "values": [
      { "category": "A", "value": 28 },
      { "category": "B", "value": 55 },
      { "category": "C", "value": 43 }
    ]
  },
  "mark": "bar",
  "encoding": {
    "x": { "field": "category", "type": "nominal" },
    "y": { "field": "value", "type": "quantitative" }
  }
}

Reference Documentation

See vega-lite-reference.md for documentation on:

  • Data types and encoding channels
  • All mark types and properties
  • Common pitfalls to avoid
  • Professional chart patterns
  • Theming and best practices

License

MIT