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 tractorjuice/arckit-gemini --skill plantuml-syntaxgit clone --depth 1 https://github.com/tractorjuice/arckit-geminiWrote 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/tractorjuice/arckit-gemini/plantuml-syntax)<a href="https://agentmods.dev/skills/tractorjuice/arckit-gemini/plantuml-syntax"><img src="https://agentmods.dev/badge/skills/tractorjuice/arckit-gemini/plantuml-syntax/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/tractorjuice/arckit-gemini/plantuml-syntax"><img src="https://agentmods.dev/badge/skills/tractorjuice/arckit-gemini/plantuml-syntax.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 | $0.00095 | $0.01197 |
| Opus 5 | $0.00048 | $0.00598 |
| Sonnet 5 | $0.00019 | $0.00239 |
| Haiku 4.5 | $0.00010 | $0.00120 |
Grade A, and why
plantuml-syntax scanned grade A with 0 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 5d 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PlantUML Syntax Reference
A comprehensive reference for PlantUML diagram types with a focus on C4-PlantUML for architecture diagrams. This skill provides syntax documentation adapted from the SpillwaveSolutions/plantuml project, supplemented with ArcKit-specific C4 layout conflict rules and best practices.
This skill ships reference material, not runnable scripts. Read the relevant reference file with Read, apply the syntax, and write the diagram into the user's artefact. Do not Bash-execute anything from references/ — they are PlantUML/C4 syntax docs, not commands.
Supported Diagram Types
Select the appropriate diagram type and read the corresponding reference file:
| Type | Reference | ArcKit Commands Using It |
|---|---|---|
| C4-PlantUML | c4-plantuml.md | /arckit:diagram (C4 Context, Container, Component) |
| Sequence Diagram | sequence-diagrams.md | /arckit:diagram (Sequence mode) |
| Class Diagram | class-diagrams.md | — |
| Activity Diagram | activity-diagrams.md | — |
| State Diagram | state-diagrams.md | — |
| ER Diagram | er-diagrams.md | — |
| Component Diagram | component-diagrams.md | — |
| Use Case Diagram | use-case-diagrams.md | — |
| Deployment Diagram | deployment-diagrams.md | — |
Styling & Errors
| Topic | Reference |
|---|---|
| Common Syntax Errors | common-syntax-errors.md |
| Styling Guide | styling-guide.md |
C4-PlantUML (Primary Use Case)
The C4-PlantUML reference is the most important file for ArcKit users. It covers:
- Include URLs for C4 libraries
- Element syntax (Person, System, Container, Component, and their variants)
- Boundary syntax (System_Boundary, Container_Boundary)
- Directional relationships (Rel_Down, Rel_Right, Rel_Up, Rel_Left, Rel_Neighbor)
- Layout constraints (Lay_Right, Lay_Down, Lay_Distance)
- LAYOUT CONFLICT RULES — critical rules to prevent rendering failures when layout hints contradict relationship directions
- Tier-based layout patterns
- Worked examples for Context, Container, and Component diagrams
What ships with it
11 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.
- references/activity-diagrams.md 4.2 KB
- references/c4-plantuml.md 15 KB
- references/class-diagrams.md 3.9 KB
- references/common-syntax-errors.md 6.3 KB
- references/component-diagrams.md 3.7 KB
- references/deployment-diagrams.md 2.7 KB
- references/er-diagrams.md 4.3 KB
- references/sequence-diagrams.md 5.5 KB
- references/state-diagrams.md 4.2 KB
- references/styling-guide.md 6.6 KB
- references/use-case-diagrams.md 3.8 KB
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.
- 5d ago Changed · +2 lines · +37 tokens per session 449ad15605cf
- 10d ago First seen · 72 lines · 58 tokens per session scan A cdbfff5c23ce
plantuml-syntax is a skill published in the GitHub repository tractorjuice/arckit-gemini (3 stars, last pushed 7d ago), licensed MIT. It adds 95 tokens to every session and 1,197 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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