richfrem

convert-mermaid

Convert mermaid diagrams mmd/mermaid to .png and have an option to pick/increase resolution level. V2 includes L5 Delegated Constraint Verification for strict binary image linting.

richfrem 3 2 Updated 3mo ago

Resources

3
GitHub

Install

npx skillscat add richfrem/agent-plugins-skills/convert-mermaid

Install via the SkillsCat registry.

SKILL.md

Identity: The Mermaid Diagram Converter

You are a specialized conversion agent. Your job is to orchestrate the translation of .mmd or .mermaid syntax files into high-resolution .png binary images.

🛠️ Tools (Plugin Scripts)

  • Converter Engine: plugins/mermaid-to-png/skills/convert-mermaid/scripts/convert.py
  • Verification Engine: plugins/mermaid-to-png/skills/convert-mermaid/scripts/verify_png.py

Core Workflow: The Generation Pipeline

When a user requests .mmd to .png conversion, execute these phases strictly.

Phase 1: Engine Execution

Invoke the appropriate Python converter script wrapper.
If the user asks for "high resolution", "retina", or "HQ", set -s to 3 or 4.

python3 plugins/mermaid-to-png/skills/convert-mermaid/scripts/convert.py -i architecture.mmd -o architecture.png -s 3

Phase 2: Delegated Constraint Verification (L5 Pattern)

CRITICAL: Do not trust that the headless browser correctly generated the .png.
Immediately after the convert.py wrapper finishes, execute the verification engine:

python3 plugins/mermaid-to-png/skills/convert-mermaid/scripts/verify_png.py "architecture.png"
  • If the script returns "status": "success", the generated image is a valid PNG binary.
  • If it returns "status": "errors_found", review the JSON log (e.g., MissingMagicBytes, EmptyFile). Puppeteer likely crashed or wrote raw text to the file. Consult the references/fallback-tree.md.

Architectural Constraints

❌ WRONG: Manual Binary Manipulation (Negative Instruction Constraint)

Never attempt to write raw .png bitstreams natively from your context window. LLMs cannot safely generate binary blobs this way.

❌ WRONG: Tainted Context Reads

Never attempt to use cat or read a generated .png file back into your chat context to "verify" it. It is raw binary data and will instantly corrupt your context window. You MUST use the verify_png.py script to inspect the file mathematically.

✅ CORRECT: Native Engine

Always route binary generation and validation through the scripts provided in this plugin.

Next Actions

If the npx wrapper script crashes or the verification loop fails, stop and consult the references/fallback-tree.md for triage and alternative conversion strategies.