Workflow API Format

ComfyUI workflows are JSON objects that describe a graph of nodes. When calling ComfyUI programmatically — whether through the Cloud API or running your own server — the workflow must be submitted in API format, a specialized JSON structure that differs from the regular save format used in the browser. This page explains the differences and how to export your workflows correctly.

Save Format vs API Format

The ComfyUI frontend can save workflows in two formats:

	Save Format	API Format
File menu	`File → Save` or `Ctrl+S`	`File → Export Workflow (API)`
File extension	`.json`	`.json`
Node keys	Node titles or labels	Numeric node IDs
Widget values	Included	Included
Position/layout data	Included (x, y, width)	Excluded
Colors/groups	Included	Excluded
Usage	Re-opening in the frontend	API submission
Can be loaded in UI	Yes	Yes, but without layout

The key difference: API format omits UI metadata (positions, colors, groups, node sizes) that is only needed for visual editing in the frontend. This keeps the JSON smaller and cleaner for programmatic use.

How to Export

Open your workflow in the ComfyUI frontend, then navigate to File → Export Workflow (API):

This will download a .json file containing only the API-relevant data:

{
  "3": {
    "inputs": {
      "seed": 156680208700286,
      "steps": 20,
      "cfg": 8,
      "sampler_name": "euler",
      "scheduler": "normal",
      "denoise": 1,
      "model": [
        "4",
        0
      ],
      "positive": [
        "6",
        0
      ],
      "negative": [
        "7",
        0
      ],
      "latent_image": [
        "5",
        0
      ]
    },
    "class_type": "KSampler",
    "_meta": {
      "title": "KSampler"
    }
  },
  "4": {
    "inputs": {
      "ckpt_name": "v1-5-pruned-emaonly-fp16.safetensors"
    },
    "class_type": "CheckpointLoaderSimple",
    "_meta": {
      "title": "Load Checkpoint"
    }
  },
  "5": {
    "inputs": {
      "width": 512,
      "height": 512,
      "batch_size": 1
    },
    "class_type": "EmptyLatentImage",
    "_meta": {
      "title": "Empty Latent Image"
    }
  },
  "6": {
    "inputs": {
      "text": "beautiful scenery nature glass bottle landscape, , purple galaxy bottle,",
      "clip": [
        "4",
        1
      ]
    },
    "class_type": "CLIPTextEncode",
    "_meta": {
      "title": "CLIP Text Encode (Prompt)"
    }
  },
  "7": {
    "inputs": {
      "text": "text, watermark",
      "clip": [
        "4",
        1
      ]
    },
    "class_type": "CLIPTextEncode",
    "_meta": {
      "title": "CLIP Text Encode (Prompt)"
    }
  },
  "8": {
    "inputs": {
      "samples": [
        "3",
        0
      ],
      "vae": [
        "4",
        2
      ]
    },
    "class_type": "VAEDecode",
    "_meta": {
      "title": "VAE Decode"
    }
  },
  "9": {
    "inputs": {
      "filename_prefix": "ComfyUI",
      "images": [
        "8",
        0
      ]
    },
    "class_type": "SaveImage",
    "_meta": {
      "title": "Save Image"
    }
  }
}

Converting Between Formats

If you have a save-format workflow and need it in API format, the simplest method is:

Open the .json file using File → Load in the frontend
Export it via File → Export Workflow (API)

For automated conversion, you can write a script that strips the x, y, width fields from each node and removes the groups and extra sections from the root JSON.

APIs Overview — Compare Cloud and Server API options
Cloud API Overview — Submit API-format workflows to Comfy Cloud
API Examples — See API-format workflows in action
Getting an API Key — Required for Cloud API and Partner Nodes

​Save Format vs API Format

​How to Export

​Converting Between Formats

​Related Pages

Save Format vs API Format

How to Export

Converting Between Formats

Related Pages