Is the PlantUML Diagram Skill skill free?

Yes. The skill itself is free from Agents365-ai/plantuml-skill. SkillProof publishes the install command and an independent test verdict at no cost.

What is the PlantUML Diagram Skill SkillProof Score?

9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.

How do I install PlantUML Diagram Skill?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use PlantUML Diagram Skill with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

PlantUML Diagram Skill

Generates and renders PlantUML diagrams to real PNG/SVG via the Kroki API, with a validate-and-self-correct loop.

by Agents365-ai · Agents365-ai/plantuml-skill

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 9.6/10
Tested: Jul 14, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · 01e7835

Ran the real render loop against the live public Kroki API: POST returned HTTP 200, a genuine 715x376 PNG landed on disk, and the vision self-check confirmed it was clean and readable — the baseline path only produces unverified .puml text with no proof it even renders.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 9/10
Docs & honesty 5/5

What PlantUML Diagram Skill does

Writes .puml source for sequence/class/ER/component/activity/state/C4 diagrams and exports it to PNG/SVG through the free Kroki API (curl only, no local Java/Graphviz needed). Triggers on explicit diagram requests and proactively when explaining systems with 3+ components; explicitly routes non-UML markdown diagrams to mermaid and hand-drawn styles to excalidraw/tldraw rather than over-claiming.

How to install PlantUML Diagram Skill

git clone https://github.com/Agents365-ai/plantuml-skill
cd plantuml-skill
mkdir -p ~/.claude/skills
cp -r skills/plantuml-skill ~/.claude/skills/plantuml-skill

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger PlantUML Diagram Skill

/plantuml-skill Generates and renders PlantUML diagrams to real PNG/SVG via the Kroki API, with a validate-and-self-correct loop.

It also activates on plain-language prompts like these:

Render a sequence diagram for our login flow as a PNG
Draw a UML diagram of the client-to-auth-service handshake
Generate a PlantUML diagram and fix it until it renders

Frequently asked questions

Is the PlantUML Diagram Skill skill free?: Yes. The skill itself is free from Agents365-ai/plantuml-skill. SkillProof publishes the install command and an independent test verdict at no cost.
Does PlantUML Diagram Skill work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 14, 2026. Verdict: Tested · Works. Ran the real render loop against the live public Kroki API: POST returned HTTP 200, a genuine 715x376 PNG landed on disk, and the vision self-check confirmed it was clean and readable — the baseline path only produces unverified .puml text with no proof it even renders.
What is the PlantUML Diagram Skill SkillProof Score?: 9.6/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 9/10, docs & honesty 5/5.
How do I install PlantUML Diagram Skill?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use PlantUML Diagram Skill with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.