Evident Charts

Evident Charts is a community skill by Randy Olson that helps your agent make charts with one clear point and check them before you see them. It works with matplotlib, seaborn, pandas, ggplot2, Plotly, Altair and Vega-Lite, and D3. What you can do with it - Ask for a chart the way you already do, for a blog, report, paper, slide, newsletter or social post, with size presets for each - Get the takeaway as the title and a cited data publisher, instead of a topic title and a guessed source - Have the data checked first for totals mixed with their parts, duplicate rows and placeholder values - Catch overlapping labels, misleading axes, colour-blindness and contrast problems with its check scripts - Critique an existing chart from its PNG, its script or both, and get ranked fixes How it works - The agent analyses the data, writes a one-line brief, picks the form, builds the chart, runs the checks and reviews the rendered image, using a separate reviewer when allowed, for up to three rounds - Each rule is tagged as experimental evidence, practitioner consensus or taste, with citations; your own instructions and style guide come first, and it reports any rule you asked it to break - Checks need Python 3.10 or later; matplotlib checks also need matplotlib and numpy, and SVG layout checks need Chrome or Chromium. Skipped checks are reported Good to know - Install it as a Claude Code plugin from the maker's own marketplace, with npx skills add rhiever/evident-charts, as a Codex plugin or as a Gemini CLI extension - MIT licensed