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Chart Image
by
Danny Shmueli
· GitHub ↗
· v2.6.35
· MIT-0
11927
Downloads
17
Stars
73
Active Installs
15
Versions
Install in OpenClaw
/install chart-image
Description
Generate publication-quality chart images from data. Supports line, bar, area, point, histogram, candlestick, pie/donut, heatmap, multi-series, and stacked c...
Usage Guidance
Safe for normal chart generation. Before installing, be comfortable with npm installing the included dependencies, and when using it, keep chart/spec/output paths controlled by the runtime rather than arbitrary user text. Avoid sending charts containing sensitive data into shared channels unless that is intended.
Capability Analysis
Type: OpenClaw Skill
Name: chart-image
Version: 2.6.35
The 'chart-image' skill is a legitimate utility for generating chart images using Vega-Lite and Sharp. The core logic in 'scripts/chart.mjs' handles data parsing and image rendering without any evidence of malicious intent, such as data exfiltration, backdoors, or unauthorized execution. The documentation in 'CAPABILITY.md' and 'SKILL.md' provides clear, safe instructions for the AI agent, specifically warning against shell injection vulnerabilities by recommending structured argument passing instead of string interpolation. No suspicious dependencies or obfuscated code were detected.
Capability Assessment
Purpose & Capability
The artifacts consistently describe a local Node/Vega-Lite/Sharp chart renderer that accepts data, CSV, or Vega-Lite specs and writes PNG/SVG chart files.
Instruction Scope
The skill invokes a local CLI and supports user-provided data, titles, spec paths, and output paths; its CAPABILITY notes appropriately tell agents to use structured argv calls and trusted runtime-controlled paths.
Install Mechanism
Setup requires npm install in the skill scripts directory with a package lock and ordinary chart-rendering dependencies; this is disclosed and purpose-aligned.
Credentials
Runtime behavior is limited to local chart input parsing and image output; no credentials, account access, background indexing, or external API calls are evidenced in the skill code.
Persistence & Privilege
Persistence is limited to user-directed generated chart files, including documented use of a persistent temp directory for attachments; there is no daemon, scheduler, privilege escalation, or self-modifying behavior.
How to Use
- Make sure OpenClaw is installed (local or Docker)
- Run the install command in chat:
/install chart-image - After installation, invoke the skill by name or use
/chart-image - Provide required inputs per the skill's parameter spec and get structured output
Version History
v2.6.35
Add x-domain support for quantitative and temporal charts, plus updated docs/examples.
v2.6.23
- Added options for axis tick count control: `--x-ticks`, `--y-ticks`, and `--y2-ticks`
- Added legend layout controls: `--legend-columns` and `--legend-label-limit`
- Added explicit order option for multi-series and stacked legends: `--series-order`
- Added global font family theming with `--font-family`
- README and documentation updated to cover new options and usage
v2.6.18
Tighten capability docs to avoid risky shell-construction examples and reduce scanner-noisy guidance.
v2.6.17
Add y2-axis formatting, plus recent chart output and label control improvements.
v2.6.14
**2.6.14 includes expanded chart customization and new options for improved data visualization.**
- Added support for `--x-sort` (including `"none"` to preserve input order).
- New chart appearance controls: `--no-points`, `--line-width`, `--point-size`, and `--bar-radius`.
- Introduced `--last-value` option to annotate the final data point.
- Added `--y-pad` for vertical axis padding.
- Documentation updated to reflect all new options and defaults.
v2.5.1
chart-image v2.5.1
- Version bump from 2.4.0 to 2.5.1.
- Documentation updated (README.md, SKILL.md): no new features or options documented.
- No changes to code structure or CLI arguments are documented.
v2.4.0
- Added general dual-axis chart support with new CLI options: `--y2-field`, `--y2-title`, `--y2-color`, `--y2-type`
- Updated documentation to include dual-axis usage (bar/area/line overlays with independent right Y-axis)
- Bumped version to 2.4.0
v2.3.0
**2.3.0 Summary:**
This version introduces new features and enhancements for chart image generation.
- New option: `--subtitle` allows adding a subtitle below the chart title.
- New option: `--hline` enables horizontal reference lines (with support for color and labels).
- New option: `--annotation` for static text annotation on charts.
- New option: `--annotations` supports an array of event markers/timeline annotations.
- Improved documentation with examples for all new options.
v2.2.0
color-scheme now works on multi-series lines, stacked bars, pie/donut (was heatmap-only); added -o shorthand for --output
v2.1.0
Added: pie/donut, candlestick, heatmap, sparklines, volume overlay, temporal x-axis, multi-series, stacked bars. Alert options: --show-change, --focus-recent, --show-values.
v2.0.0
Major update with focus-recent, show-values, dark mode improvements
v1.2.0
**Adds multi-series, stacked bar, and sparkline chart options.**
- Added support for multi-series line charts via `--series-field` option.
- Introduced stacked bar charts using `--stacked` and `--color-field`.
- Enabled sparkline (mini inline) chart output with `--sparkline` flag.
- Updated documentation to describe new options and provide usage examples.
- Declared a capability block in SKILL.md for chart-generation.
v1.1.0
Added --focus-recent N to zoom into last N data points for alert-style charts
v1.0.1
Improved docs: added Fly.io deployment benefits, comparison with alternatives
v1.0.0
Initial release: Vega-Lite charts with dark mode, peak labels, change annotations
Metadata
Frequently Asked Questions
What is Chart Image?
Generate publication-quality chart images from data. Supports line, bar, area, point, histogram, candlestick, pie/donut, heatmap, multi-series, and stacked c... It is an AI Agent Skill for Claude Code / OpenClaw, with 11927 downloads so far.
How do I install Chart Image?
Run "/install chart-image" in the OpenClaw or Claude Code chat to install it in one step — no extra setup required.
Is Chart Image free?
Yes, Chart Image is completely free, licensed under MIT-0. You can download, install and use it at no cost.
Which platforms does Chart Image support?
Chart Image is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).
Who created Chart Image?
It is built and maintained by Danny Shmueli (@dannyshmueli); the current version is v2.6.35.
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