Awesome MCP › Design & Visualization

isaacwasserman/mcp-vegalite-server

⭐ 100 Python added to this list on 2025-05-06 repository created 2024-12-12

mcp-vegalite-server is a Model Context Protocol server that gives a language model a way to draw charts from data it has assembled, using Vega-Lite as the description language. It works in two steps and exposes one tool for each. The save_data tool takes a name and an array of objects representing a table of data, stores that table on the server and returns a success message, which lets a model push an aggregation it has just computed without repeating the rows in every later call. The visualize_data tool then takes the name of a stored table and a Vega-Lite specification as a JSON string, and renders the named data through that specification. What comes back depends on how the server was started. With the output_type option set to text, the tool returns a success message plus an artifact key holding the complete Vega-Lite specification with the data inlined, which suits a client that can render Vega-Lite itself or hand the specification to an artifact viewer. With output_type set to png, the server rasterises the chart and returns a base64 encoded PNG inside the MCP ImageContent container, which suits clients that can only display images. Because the visualisation grammar is Vega-Lite rather than a fixed menu of chart types, the model chooses the marks, encodings, scales and aggregations itself in the specification it writes, and the server does not constrain the chart forms available. It is written in Python and run with uv from a local checkout, pointing at the project directory and passing the output type flag; the README shows the matching claude_desktop_config.json entry for Claude Desktop. It is aimed at analysis sessions where a model queries or computes data and then needs to show it.

https://github.com/isaacwasserman/mcp-vegalite-server

mcpmcp-serverpythonvega-litedata-visualizationchartspng