name: diagram-generator
description: Generate a diagram and route to the right engine — draw.io XML (precise, editable, C4, swimlanes) or Excalidraw JSON (hand-drawn, sketch, wireframes). One entry for flowcharts, architecture, ER, sequence, mind maps. Don't use for Mermaid or slides.
license: MIT
effort: high
metadata:
    version: 1.1.2
    author: "Luong NGUYEN <luongnv89@gmail.com>"

Diagram Generator

Single entry point for "make me a diagram". This umbrella picks the right engine and hands off to

it — both produce the same diagram taxonomy (flowchart, architecture, C4, ER, sequence, mind map)

through the same four phases (Understand → Propose → Generate → Validate); they differ only in

output format and aesthetic.

Which engine?

Routing rules:

• The user names a format or tool ("draw.io", "diagrams.net", "Excalidraw", "whiteboard sketch") → use that engine.
• The user names an editing target ("I'll tweak it in draw.io", "import to Confluence") → draw.io.
• The user wants a hand-drawn / sketch / wireframe look → Excalidraw.
• No format signal → ask one question: "Precise and editable (draw.io) or hand-drawn sketch (Excalidraw)?" Keep routing blocked until the user answers. Only after explicit delegation such as "just pick", "choose for me", or "use the default", choose draw.io for architecture/C4/technical diagrams and Excalidraw for wireframes/brainstorms.
• The user asks for Mermaid, a slide deck, or brand/marketing graphics → out of scope; say so (Mermaid is native markdown; use a presentation or design tool for the others).

How to use

Once the engine is chosen, invoke the nested skill by name — the runtime resolves names regardless

of filesystem path:

• /drawio-generator — generate draw.io XML
• /excalidraw-generator — generate Excalidraw JSON

Each engine owns its full workflow, references/, agents/, and validation checks. This umbrella

stays short to protect the agent's context budget; it only routes.

Prerequisites

1. Confirm at least one nested engine is installed and callable.
2. Require enough diagram content to identify nodes, relationships, and intended audience; ask for

missing essentials before routing.

1. Check whether the requested output path already exists. Let the selected engine run its own

confirmation, backup, dry-run, error, and rollback safeguards before any overwrite.

If the user explicitly requested a format, tool, editing target, or aesthetic and its engine is unavailable,

stop and explain which nested skill must be installed; provide the matching command

(asm install github:luongnv89/skills:skills/diagram-generator/drawio-generator or

asm install github:luongnv89/skills:skills/diagram-generator/excalidraw-generator) and ask the user to

install it or explicitly change the requested output. Do not substitute the other engine. If no format or aesthetic was explicit, an available

engine may be offered as a fallback only after explaining the output difference and receiving user approval.

If neither engine is available, fail with an installation error and name both required skills. Never invent

XML or JSON under the wrong engine as a fallback.

Example

Input: "Draw a sketchy onboarding wireframe for mobile."
Route: excalidraw-generator
Expected output: one validated .excalidraw JSON artifact

Acceptance Criteria

Verify every routed run:

• Exactly one engine is selected unless the user explicitly requests both formats.
• The selected engine matches the requested format, editing target, or aesthetic.
• The nested workflow reaches its Validate phase and produces its expected output artifact.
• The artifact passes the engine's structural checks; validation errors are reported, not hidden.
• Existing files are not overwritten without the selected engine's required confirmation or backup.

Step Completion Reports

After routing, emit:

◆ Route Diagram
  Engine available:    √ pass
  Route justified:     √ pass
  Output validated:    √ pass
  Result:              PASS | FAIL | PARTIAL

Use × fail — reason when a check fails. Report PASS only after the nested engine's acceptance

criteria and expected result are verified.

Edge Cases

• User explicitly wants both formats — generate with one engine first, then offer to regenerate the same diagram in the other.
• Ambiguous, no answer to the routing question — keep routing blocked and ask the question again; silence or timeout is not approval to choose an engine. Apply the routing heuristics only when the user explicitly delegates the choice (for example, "just pick", "choose for me", or "use the default").
• Explicitly requested engine is unavailable — do not fall back. Report the unavailable nested skill, provide its installation guidance, and ask the user to install it or explicitly approve a different format/aesthetic.
• No explicit format and the selected engine is unavailable — offer the installed engine as an alternative, explain its format/aesthetic, and route only after explicit user approval.