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 xonika9/agent-skills --skill x9-diagramsgit clone --depth 1 https://github.com/xonika9/agent-skillsWrote 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/xonika9/agent-skills/x9-diagrams)<a href="https://agentmods.dev/skills/xonika9/agent-skills/x9-diagrams"><img src="https://agentmods.dev/badge/skills/xonika9/agent-skills/x9-diagrams/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/xonika9/agent-skills/x9-diagrams"><img src="https://agentmods.dev/badge/skills/xonika9/agent-skills/x9-diagrams.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 | $0.00132 | $0.01367 |
| Opus 5 | $0.00066 | $0.00683 |
| Sonnet 5 | $0.00026 | $0.00273 |
| Haiku 4.5 | $0.00013 | $0.00137 |
Grade A, and why
x9-diagrams 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 11d 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 — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Diagrams
Design, create, review, and convert diagrams while keeping the visual argument and the native source independently correct.
The machine-readable onboarding contract lists external prerequisites.
Resolve two decisions
First choose the view that expresses the relationship: flowchart, sequence, state, architecture, data model, hierarchy, timeline, comparison, or another supported view. Then choose the delivery format. Do not let a familiar file format decide the diagram type.
An explicit format wins when it can express the required structure. If it creates a material limitation, explain the limitation and offer an alternative without silently changing the deliverable.
Use this matrix when the format is open:
| Constraint | Excalidraw | Mermaid | draw.io |
|---|---|---|---|
| Manual coordinate control | Strong | Weak; layout is automatic | Strong |
| Collaborative visual editing | Strong in Excalidraw | Depends on the host | Strong in diagrams.net |
| Text diff and code review | Poor | Strong | Moderate with uncompressed XML |
| Automatic layout | Manual-first | Strong | Available, but manual geometry remains explicit |
| Free spatial composition | Strong | Limited | Strong |
| Pages, layers, containers, shape libraries | Limited | Limited and renderer-dependent | Strong |
| Direct Markdown/chat rendering | Rare | Strong when supported | Rare |
| Native editability after handoff | .excalidraw |
Mermaid source in a compatible editor | .drawio XML |
| Reliable validation and rendering | Needs checker plus faithful renderer | Needs target parser plus renderer | Needs XML checks plus compatible editor/exporter |
Prefer the format whose native editor, validator, and renderer are available in the delivery environment. If none can provide visual proof, produce the requested native source only when still useful and label the result DEGRADED.
Own the visual argument
Settle one question, audience, delivery viewport, entry point, and dominant reading direction. Preserve exact facts and identifiers while shortening explanatory labels. Model semantic nodes, boundaries, and relationships before syntax or coordinates.
What ships with it
7 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.
- 11d ago First seen · 77 lines · 132 tokens per session scan A 1dd8bb006bd6
x9-diagrams is a skill published in the GitHub repository xonika9/agent-skills (4 stars, last pushed 6d ago), licensed MIT. It adds 132 tokens to every session and 1,367 once invoked, about $0.0007 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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