Phase 6: ComfyUI — Workflow Engine · 55 min · Python · ComfyUI · websockets

ComfyUI API Integration

Design visually, execute programmatically — the /prompt, /history, /view API is how ComfyUI becomes production infrastructure.

Hiring signal: ComfyUI API integration (/prompt, /history, /view, WebSocket) is the core skill for ComfyUI Pipeline Engineer roles — it's tested in every ComfyUI-focused interview.

What you will learn

Use the /prompt endpoint: POST API-format workflow JSON to trigger execution
Use the /history endpoint: poll for completed workflow results
Use the /view endpoint: retrieve generated output images/videos
Track execution via WebSocket events: node-by-node completion progress

The Problem

A team designs a great image generation workflow in ComfyUI's visual editor. Now they need to:

Execute it from a Python backend (not the UI)
Track execution progress (which node is running)
Retrieve the generated image programmatically
Handle errors and retries

They don't know ComfyUI has a REST API and WebSocket for programmatic control. They try to screen-scrape the UI — that's not production-grade.

ComfyUI API integration is the core skill for ComfyUI Pipeline Engineer roles — it's tested in every ComfyUI-focused interview.

What you'll build
Use the /prompt endpoint to trigger workflow execution, /history to poll for results, /view to retrieve output images, and WebSocket to track node-by-node execution progress. Build a complete Python client for ComfyUI.

ComfyUI API Endpoints

API Overview

Endpoint	Method	Purpose
`/prompt`	POST	Submit workflow for execution
`/history`	GET	Check execution history/results
`/view`	GET	Retrieve generated output files
`/queue`	GET	Check queue status
`/interrupt`	POST	Cancel current execution
`/object_info`	GET	Get available node types and parameters
`/system_stats`	GET	Get system info (GPU, VRAM, etc.)

Base URL

http://127.0.0.1:8188

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers /prompt — Submit Workflow, /history — Poll for Results, /view — Retrieve Output, WebSocket — Real-Time Progress, Complete Python Client, Error Handling, Key Takeaways, What's Next — plus a hands-on lab, quiz, and project artifact.

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