---

name: workflow-execution description: "Build, validate, debug, and reason about ComfyUI API prompt JSON, graph execution, caching, async nodes, output metadata, blueprints, and inference failures." disable-model-invocation: true metadata: disco-role: operating license: GPL 3.0

Workflow Execution

Use this sub-skill when an agent needs to convert or check a ComfyUI API prompt, debug prompt graph errors, explain why nodes execute or are cached, validate workflow templates/blueprints, or reason about async/lazy execution behavior.

When to Use

• Validate a prompt before sending it to ComfyUI's /prompt endpoint.
• Explain the difference between exported UI workflow JSON and API prompt JSON.
• Find missing node ids, malformed [node_id, output_index] links, absent class_type, or non-object inputs values.
• Diagnose execution failures involving validation, lazy inputs, async nodes, progress messages, output metadata, cache reuse, or expensive inference runs.
• Review a blueprint or reusable template for placeholder safety before filling model names or parameters.

For endpoint submission, queue/history/websocket handling, and live server transport, use ../server-api/SKILL.md. For node schema/class implementation details, use ../custom-nodes/SKILL.md. For model filenames, search paths, memory modes, and backend flags, use ../models-config/SKILL.md.

Fast Workflow

1. Decide whether the file is API prompt JSON or UI workflow JSON; convert/export to API format before POSTing.
2. Run python scripts/validate_prompt_graph.py prompt.json for structural checks that do not import ComfyUI or load models.
3. Check every node has string id, class_type, and inputs; every link is ["upstream_id", output_index] or [upstream_id, output_index].
4. Verify node-specific input names/types against the active node registry or docs; the bundled validator intentionally cannot know custom node schemas.
5. Confirm output nodes such as save/preview nodes are reachable from intended generation nodes.
6. If live execution fails, inspect ComfyUI validation errors first, then graph dependency/cycle errors, then async/runtime/model/backend errors.

References

• references/prompt-format.md explains API prompt JSON shape, link syntax, and UI workflow differences.
• references/execution-semantics.md explains validation order, topological execution, lazy inputs, async behavior, output metadata, and cache modes.
• references/blueprints-and-templates.md explains blueprint/template handling and safe placeholder validation.
• references/troubleshooting.md maps common prompt/execution failures to fixes.
• scripts/validate_prompt_graph.py performs self-contained structural validation for prompts and template-like JSON.

Grounding Notes

This guidance is distilled from ComfyUI's execution engine, graph scheduler, cache implementation, async/progress behavior, inference patterns, API examples, and blueprint/template formats. Full live execution can require optional model/backend capabilities; validate prompt shape separately from model availability and hardware-specific runtime behavior.