Diagram Design
cathrynlavery/diagram-design
Creates branded diagrams, from architecture, flowchart and sequence to charts and maps, as self-contained HTML with inline SVG, with import from draw.io, Mermaid and Excalidraw.
Draw diagrams as .excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane.
Install Excalidraw
$ npx skills add autonomous-ai/openharness --skill excalidraw -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install autonomous-ai/openharness excalidraw --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .claude/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .claude/skills/excalidraw && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .claude/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidrawType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add autonomous-ai/openharness --skill excalidraw -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install autonomous-ai/openharness excalidraw --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .agents/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .agents/skills/excalidraw && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .agents/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add autonomous-ai/openharness --skill excalidraw -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install autonomous-ai/openharness excalidraw --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .cursor/skills/excalidraw && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .cursor/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/autonomous-ai/openharness.git --path store/agents/excalidraw/skills/excalidraw--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add autonomous-ai/openharness --skill excalidraw -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install autonomous-ai/openharness excalidraw --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .gemini/skills/excalidraw && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .gemini/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install autonomous-ai/openharness excalidrawInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add autonomous-ai/openharness --skill excalidraw -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .github/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .github/skills/excalidraw && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .github/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add autonomous-ai/openharness --skill excalidraw -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install autonomous-ai/openharness excalidraw --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/autonomous-ai/openharness.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/store/agents/excalidraw/skills/excalidraw .opencode/skills/excalidraw && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "excalidraw" agent skill from https://github.com/autonomous-ai/openharness/tree/main/store/agents/excalidraw/skills/excalidraw into .opencode/skills/excalidraw/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "excalidraw", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
excalidraw- GitHub stars
- 1.2k
- Token cost
- ~721 tokens
- SKILL.md length
- 297 words
- Files
- 1
- Skills in repo
- 99
- Repo updated
- First seen
- Licence
- MIT
At a glance
Draw diagrams as .excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane.
- Any request that ends in a diagram
- SKILL.md covers Write with the helper, not by…, Layout that reads and Editing the JSON directly
- Calls python3
- Tasks that involve Diagrams
What it does
Excalidraw is an agent skill from autonomous-ai/openharness. Draw diagrams as .excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane. Use for any request that ends in a diagram.
Its SKILL.md is about 720 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Development, covering Diagrams. It works with Excalidraw. The repository describes itself as: The ultimate harness for coding agents and beyond. All your agents. All your machines. One command center. Start with code, then follow your curiosity and build across… The licence is MIT.
When your agent uses it
- Any request that ends in a diagram
- Tasks that involve Diagrams
Example prompts
- “/excalidraw”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit 74c2733. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
python3
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Excalidraw loads about 721 tokens when it runs. Until then it costs about 62 tokens; SKILL.md has 297 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from autonomous-ai/openharness at commit 74c2733, republished under its MIT licence (© autonomous-ai). 297 words, ~721 tokens.
Download SKILL.mdSave it as
.claude/skills/excalidraw/SKILL.md (or your agent's skills folder).- name
- excalidraw
- description
- Draw diagrams as .excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane. Use for any request that ends in a diagram.
excalidraw
An .excalidraw file is JSON: { type: "excalidraw", version: 2, elements: [...], appState, files }.
Elements are rectangles, ellipses, diamonds, text, arrows, lines, frames. The pane is Excalidraw's own
editor in view mode; the same file opens in excalidraw.com and the VS Code extension.
Write with the helper, not by hand
scene.py is on PYTHONPATH ($EXCALIDRAW_TOOLCHAIN/scene.py). One script per diagram:
from scene import Scene
s = Scene() # a whiteboard: light canvas, Excalidraw's palette
s.title("Order service", 0, -110)
api = s.box(0, 0, "API", color="blue") # rectangle; shape="ellipse" | "diamond"
db = s.box(320, 0, "Postgres", color="green", shape="ellipse")
q = s.box(0, 180, "Queue", color="yellow", shape="diamond")
s.arrow(api, db, "SQL") # bound at both ends; dashed=True, both=True
s.arrow(api, q, "job", dashed=True)
s.note(660, 0, "Retries: 3, backoff 2s", color="yellow")
s.frame([api, db, q], "Backend") # a named frame around members
s.save("diagram.excalidraw")Then the verdict: python3 "$EXCALIDRAW_TOOLCHAIN/verdict.py" (or … verdict.py flows/x.excalidraw).
Colours: blue, green, yellow, red, purple, pink, orange, teal, gray, none — Excalidraw's palette.
Fonts: font=1 hand-drawn (default), 2 sans, 3 mono (code, paths, hostnames).
Layout that reads
- A grid of 300 px columns and 180 px rows; boxes 160×72 unless a label needs more. Left to right for flow, top to bottom for hierarchy, never diagonal chains.
- One idea per box, two or three words. The verb goes on the arrow ("SQL", "publishes", "HTTPS").
- Frames for boundaries (a service, a network, a team); notes for the one fact that matters (a limit, a retry, a port). At most ~12 boxes per diagram — split otherwise.
- Name every frame: the pane's Present mode steps through frames in reading order (top to bottom, left to right) with the frame name as the step title, so frames double as the walkthrough.
exports/is where the pane saves PNG/SVG exports when the user asks for them; do not write diagrams there.- Sequence diagrams: actors as boxes in a row at y=0, lifelines as
s.arrow(a, b, "…")rows stepping down 100 px; sketches: the hand font, few colours.
Editing the JSON directly
For a tweak (move a box, rename a label) edit the file: change x/y, or the text AND
originalText of a text element. Keep ids and boundElements as they are; the verdict flags a
binding that points at nothing. Regenerate from the script for anything larger.
© autonomous-ai, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in store/agents/excalidraw/skills/excalidraw of autonomous-ai/openharness.
Open the folder on GitHubat commit 74c2733
Compare with similar skills
Excalidraw next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Excalidraw this skillautonomous-ai/openharness | 1.2k | — | ~721 | Automated safety check: Pass | MIT | |
| Diagram Designcathrynlavery/diagram-design | 47k | 1 repos | ~7.5k | Automated safety check: Pass | MIT | |
| Excalidraw Diagramcoleam00/excalidraw-diagram-skill | 5k | 2 repos | ~6.1k | Automated safety check: Pass | None | |
| Excalidraw Diagrambreferrari/obsidian-mind | 5k | — | ~3.9k | Automated safety check: Pass | MIT | |
| Excalidraw Skillyctimlin/mcp_excalidraw | 2.5k | — | ~4.6k | Automated safety check: Pass | MIT | |
| Lanshu Animated Architecture Diagramcclank/lanshu-animated-architecture-diagram | 994 | — | ~1.1k | Automated safety check: Pass | MIT |
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Excalidraw Diagram
coleam00/excalidraw-diagram-skill
Create Excalidraw diagram JSON files that make visual arguments.
Excalidraw Diagram
breferrari/obsidian-mind
Generate Excalidraw diagrams from text content. An agent skill from breferrari/obsidian-mind.
Excalidraw Skill
yctimlin/mcp_excalidraw
Excalidraw canvas toolkit for creating, editing, and refining diagrams on a live canvas.
Lanshu Animated Architecture Diagram
cclank/lanshu-animated-architecture-diagram
Create premium hand-drawn architecture and process diagrams in the Lanshu animated GIF style, with editable .excalidraw files, static PNG previews, and genuinely animated GIFs with moving flow…
Excalidraw Diagram Studio
tech-leads-club/agent-skills
Generates Excalidraw diagram files from plain descriptions, choosing among flowcharts, mind maps, architecture, swimlane, class, sequence and ER diagrams.
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Related
Works with
Categories
Questions about Excalidraw
What does Excalidraw do?
Draw diagrams as .excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane. Excalidraw is an agent skill from autonomous-ai/openharness.excalidraw files — architectures, flows, sequences, whiteboard sketches — with the scene helper or by editing the JSON, judged by the verdict and shown hand-drawn in the pane.
When should I use Excalidraw?
Excalidraw fits situations like: any request that ends in a diagram; tasks that involve Diagrams.
How do I install Excalidraw in Claude Code?
Run `npx skills add autonomous-ai/openharness --skill excalidraw -a claude-code`. Or copy the skill folder (store/agents/excalidraw/skills/excalidraw in autonomous-ai/openharness) into .claude/skills/excalidraw in your project. Claude Code loads it when a task matches its description.
How do I install Excalidraw in Codex?
Run `npx skills add autonomous-ai/openharness --skill excalidraw -a codex`. Or copy the skill folder (store/agents/excalidraw/skills/excalidraw in autonomous-ai/openharness) into .agents/skills/excalidraw in your project. Codex loads it when a task matches its description.
Can I use Excalidraw in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add autonomous-ai/openharness --skill excalidraw -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/excalidraw, .gemini/skills/excalidraw, .github/skills/excalidraw and .opencode/skills/excalidraw in your project.
What does Excalidraw need to run?
Going by SKILL.md and its folder, Excalidraw needs the command-line tools its instructions call (python3). Our summary lists: Python 3.
Does Excalidraw access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Excalidraw safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Excalidraw use?
Excalidraw is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Excalidraw use?
About 721 tokens (SKILL.md is roughly 2.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Excalidraw?
Skills that share tags, products or a category with Excalidraw: Diagram Design (cathrynlavery/diagram-design, 47k stars), Excalidraw Diagram (coleam00/excalidraw-diagram-skill, 5k stars), Excalidraw Diagram (breferrari/obsidian-mind, 5k stars) and Excalidraw Skill (yctimlin/mcp_excalidraw, 2.5k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Excalidraw?
autonomous-ai (a GitHub organization) maintains it in autonomous-ai/openharness, which has 1,194 GitHub stars. The repository holds 99 skills in this directory. The repository was last updated on October 9, 2026.
Source: autonomous-ai/openharness on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.