Prompt to Drawio

Generate and edit draw.io artifacts from natural-language prompts without a frontend. Use when the user asks for prompt-to-diagram workflows that need `.draw...

Use this skill to run a CLI-only version of Next AI Draw.io capabilities.

Capability Set

1. Prompt -> .drawio generation.
2. Prompt-driven edit on existing diagrams (ID-based operations).
3. Optional image export (png, svg, pdf, jpg).
4. Context ingestion from local files (txt/md/json/csv/pdf/image) and URLs.
5. Shape library documentation injection (aws4, gcp2, azure2, kubernetes, etc.).
6. Visual quality validation with retry loops.
7. History snapshot backup before edits.

Runtime Script

Primary entrypoint:

• /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py

Subcommands:

• generate
• edit
• export
• validate
• library

Compatibility:

• Legacy usage without subcommand is treated as generate.

Runtime Modes

Mode A (default, recommended): in-session LLM mode

• If the assistant is directly executing this skill inside a Codex/LLM session, generation/edit can be done by the session model itself.
• In this mode, DRAWIO_LLM_API_KEY is not required by the skill workflow.

Mode B: standalone CLI mode

• If you run prompt_to_drawio.py generate|edit|validate as an independent subprocess that must call a model API by itself, then API key is required.
• Supported env key names: DRAWIO_LLM_API_KEY (preferred) or OPENAI_API_KEY.
• Default key-loading rule: script auto-loads nearest .env from current working directory upward (first match), then reads key variables from it.
• Override dotenv path with DRAWIO_DOTENV_FILE=/absolute/path/.env.
• Precedence: CLI flag --api-key/--validation-api-key > existing process env > auto-loaded .env.
• New runtime controls:
  • --no-dotenv: disable .env auto-loading.
  • --dotenv-file /abs/path/.env: use specific dotenv file.
  • --no-config-summary: silence startup effective-config print.
  • --no-model-preflight: skip provider-side model existence preflight.

Optional env overrides for standalone CLI mode:

export DRAWIO_LLM_API_KEY="<secret>"
export DRAWIO_LLM_BASE_URL="https://api.openai.com/v1"
export DRAWIO_LLM_MODEL="gpt-4.1"
export DRAWIO_VALIDATION_MODEL="gpt-4.1"
export DRAWIO_VALIDATION_API_KEY="$DRAWIO_LLM_API_KEY"
export DRAWIO_VALIDATION_BASE_URL="$DRAWIO_LLM_BASE_URL"

Google OpenAI-Compatible Example

export DRAWIO_LLM_API_KEY="<google_ai_studio_key>"
export DRAWIO_LLM_BASE_URL="https://generativelanguage.googleapis.com/v1beta/openai/"
export DRAWIO_LLM_MODEL="gemini-3-pro-preview"

export DRAWIO_VALIDATION_API_KEY="$DRAWIO_LLM_API_KEY"
export DRAWIO_VALIDATION_BASE_URL="$DRAWIO_LLM_BASE_URL"
export DRAWIO_VALIDATION_MODEL="gemini-3-pro-preview"

Model naming notes:

• Recommended baseline: gemini-3-pro-preview (or latest model shown by provider model listing).
• Avoid stale/nonexistent names such as gemini-3-pro unless your provider explicitly lists it.

Workflows

1) Create Diagram

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py generate \
  --prompt "Create a user login + MFA + session flowchart" \
  --out-drawio "/absolute/path/auth-flow.drawio" \
  --out-image "/absolute/path/auth-flow.png" \
  --validate \
  --validate-soft

2) Create Diagram from Image/PDF/URL Context

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py generate \
  --prompt "Replicate architecture style and improve readability" \
  --file "/absolute/path/reference-arch.png" \
  --file "/absolute/path/requirements.pdf" \
  --url "https://example.com/spec" \
  --shape-library aws4 \
  --out-drawio "/absolute/path/cloud.drawio" \
  --out-image "/absolute/path/cloud.svg"

3) Edit Existing Diagram

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py edit \
  --in-drawio "/absolute/path/cloud.drawio" \
  --prompt "Add WAF before ALB and split app tier into two services" \
  --out-drawio "/absolute/path/cloud-v2.drawio" \
  --out-image "/absolute/path/cloud-v2.png" \
  --validate

4) Export Only

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py export \
  --in-drawio "/absolute/path/cloud-v2.drawio" \
  --out-image "/absolute/path/cloud-v2.pdf"

5) Validation Only

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py validate \
  --in-drawio "/absolute/path/cloud-v2.drawio" \
  --fail-on-critical

6) Shape Library Discovery

python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py library --list
python3 /Users/zhaofengli/.codex/skills/prompt-to-drawio/scripts/prompt_to_drawio.py library --name aws4

Output Contract

Always surface generated file paths exactly as printed by script:

• DRAWIO_FILE=...
• IMAGE_FILE=... (if requested and successful)
• BACKUP_FILE=... (for edits)
• VALIDATION_JSON= block when validation runs

Diagnostics:

• On startup, script prints effective runtime config summary to stderr (dotenv source, effective model/base-url, key presence mask).
• On JSON parse failures, raw model response is dumped to a temp file and the error includes that path.

Do not claim export success unless target file exists.