TrueGrowth/openspec/changes/add-comfyui-image-engine/design.md

Context

The existing local image provider can register models and route to OpenAI-compatible /images/generations, but it cannot execute ComfyUI workflows or inspect ComfyUI model/node availability.

Goals / Non-Goals

• Goals: connect to local 127.0.0.1:8188, inspect ComfyUI status and nodes, run built-in text-to-image workflows, and return generated images to TrueGrowth tasks/assets.
• Non-Goals: bundling ComfyUI, silently installing models/custom nodes, replacing TrueGrowth business workflows, or exposing remote LAN ComfyUI by default.

Decisions

• Treat ComfyUI as a local image engine behind TrueGrowth APIs.
• Keep online text/script providers and existing avatar/voice/video runtimes unchanged.
• Start with polling /history/{prompt_id} after POST /prompt; websocket can be added later without changing the public TrueGrowth API.
• Use API-format workflow JSON templates for SDXL and Flux Schnell.

Risks / Trade-offs

• Workflow templates depend on node availability and model filenames in ComfyUI.
• Some Flux installs require custom nodes or newer ComfyUI versions; missing nodes are reported instead of hidden.
• Model downloads and licenses remain user-confirmed.