Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add HK-hub/AgentSkills --skill plantuml-skillgit clone --depth 1 https://github.com/HK-hub/AgentSkillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/hk-hub/agentskills/plantuml-skill)<a href="https://agentmods.dev/skills/hk-hub/agentskills/plantuml-skill"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/plantuml-skill/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/hk-hub/agentskills/plantuml-skill"><img src="https://agentmods.dev/badge/skills/hk-hub/agentskills/plantuml-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00114 | $0.04790 |
| Opus 5 | $0.00057 | $0.02395 |
| Sonnet 5 | $0.00023 | $0.00958 |
| Haiku 4.5 | $0.00011 | $0.00479 |
Grade B, and why
plantuml-skill scanned grade B with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
sudo apt install graphviz # Ubuntu Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
compatibility: Requires curl on PATH (pre-installed on macOS/Linux/Windows Git Bash). Default renderer is the public Kroki API at https://kroki.io; can also point to a local Kroki Docker instance, or fall back to a local This is a copy
100% identical to plantuml-skill — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 506 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PlantUML Diagram Skill
Overview
Generate .puml PlantUML diagram files and export to PNG/SVG using Kroki — a cloud rendering API that requires no local installation beyond curl.
Format: .puml (PlantUML text)
Renderer: Kroki API (https://kroki.io) — just curl, no Java needed
Output: PNG, SVG
Diagram types: sequence, component, class, ER, activity, use case, state, C4, and more
When to Use
Explicit triggers:
- "plantuml diagram", "sequence diagram", "class diagram", "component diagram"
- "UML", "activity diagram", "use case diagram", "state machine"
- "visualize", "draw", "diagram", "flowchart", "architecture chart"
Proactive triggers:
- Explaining a system with 3+ interacting components
- Describing API flows, authentication sequences, message passing
- Showing class hierarchies, database schemas, or ER models
- Illustrating state machines or lifecycle flows
When NOT to use it — route elsewhere:
- General, non-UML quick diagrams embedded in Markdown → mermaid.
- Freeform, heavily-styled, or branded diagrams needing pixel control → drawio.
- A hand-drawn / sketchy look → excalidraw or tldraw.
Modes
Once triggered, route by what the user actually wants — then run the shared render loop (Steps 4–8):
| Mode | The user wants… | Entry point |
|---|---|---|
| Generate (default) | a diagram from a text description | Steps 1–8 below |
| From code | a diagram of existing source code | references/from-source-code.md → Steps 4–8 |
| Embed | the PlantUML inside a Markdown doc rendered to images | references/markdown-embed.md |
| Refine | to change an existing diagram | load its .puml, apply the minimal edit (Step 7), re-render (Steps 4–6) |
| Review | to know whether an existing diagram is readable / correct | run the Step 6 vision self-check on the image |
Prerequisites
Option A: Kroki API (recommended — no install)
# Just needs curl (pre-installed on macOS/Linux/Windows Git Bash)
curl --version
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 506 lines · 114 tokens per session scan B 77d383c6aeec
plantuml-skill is a skill published in the GitHub repository HK-hub/AgentSkills (6 stars, last pushed 25d ago), licensed MIT. It adds 114 tokens to every session and 4,790 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it B with 2 findings (asks for root, makes network calls). It is 100% identical to plantuml-skill, differing in 0 lines, and is treated as a copy.
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