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 sigistry/marketplace --skill mermaid-diagramsgit clone --depth 1 https://github.com/sigistry/marketplaceWrote 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/sigistry/marketplace/mermaid-diagrams)<a href="https://agentmods.dev/skills/sigistry/marketplace/mermaid-diagrams"><img src="https://agentmods.dev/badge/skills/sigistry/marketplace/mermaid-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/sigistry/marketplace/mermaid-diagrams"><img src="https://agentmods.dev/badge/skills/sigistry/marketplace/mermaid-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 | $0.00100 | $0.02503 |
| Opus 5 | $0.00050 | $0.01252 |
| Sonnet 5 | $0.00020 | $0.00501 |
| Haiku 4.5 | $0.00010 | $0.00250 |
Grade A, and why
mermaid-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 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.
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 — 215 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Mermaid Diagrams
Purpose
Provide diagram type selection guidance, Mermaid syntax knowledge, and visual conventions for generating accurate, readable diagrams. Apply these standards when creating architecture diagrams, flowcharts, sequence diagrams, entity-relationship diagrams, class diagrams, state machines, or any other Mermaid-supported visualization.
Diagram Type Selection
Choose the diagram type based on what needs to be communicated. Use the following table to match the user's goal to the appropriate diagram type.
| Goal | Diagram Type | Mermaid Keyword | Best For |
|---|---|---|---|
| Show how components connect | Flowchart / Graph | graph or flowchart |
System architecture, service dependencies, data pipelines |
| Show message flow over time | Sequence Diagram | sequenceDiagram |
API call chains, authentication flows, microservice communication |
| Model database structure | ER Diagram | erDiagram |
Database schemas, data models, entity relationships |
| Show class structure and inheritance | Class Diagram | classDiagram |
Object-oriented design, interface hierarchies, module APIs |
| Model state transitions | State Diagram | stateDiagram-v2 |
Order lifecycles, UI states, workflow engines, FSMs |
| Show a timeline of work | Gantt Chart | gantt |
Project schedules, migration timelines, sprint plans |
| Show Git branching | Git Graph | gitGraph |
Branching strategies, release flows, merge patterns |
| Visualize user journeys | User Journey | journey |
UX flows, customer experience mapping |
When the goal is ambiguous, prefer flowchart/graph diagrams as the default -- they are the most flexible and widely understood.
Graph Direction
Select graph direction based on the content structure and reading flow.
| Direction | Code | Use When |
|---|---|---|
| Top to Bottom | TB or TD |
Hierarchies, org charts, inheritance trees, call stacks |
| Left to Right | LR |
Pipelines, data flows, sequential processes, timelines |
| Bottom to Top | BT |
Dependency trees where leaves are at the top |
| Right to Left | RL |
Reverse flows, rarely needed |
What ships with it
1 file 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 · 215 lines · 100 tokens per session scan A b7b29d821717
mermaid-diagrams is a skill published in the GitHub repository sigistry/marketplace (3 stars, last pushed today), licensed MIT. It adds 100 tokens to every session and 2,503 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 2026-09-03.
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