comfyui-core

1# ComfyUI Core Knowledge
2 
3## Workflow JSON Format (API Format)
4 
5ComfyUI workflows are JSON objects mapping string node IDs to node definitions:
6 
7```json
8{
9  "1": {
10    "class_type": "CheckpointLoaderSimple",
11    "inputs": { "ckpt_name": "sd_xl_base_1.0.safetensors" },
12    "_meta": { "title": "Load Checkpoint" }
13  },
14  "2": {
15    "class_type": "CLIPTextEncode",
16    "inputs": { "text": "a cat", "clip": ["1", 1] },
17    "_meta": { "title": "Positive Prompt" }
18  }
19}
20```
21 
22### Key Rules
23 
24- Node IDs are strings of integers (`"1"`, `"2"`, etc.)
25- `class_type` is the exact Python class name of the node
26- `inputs` contains both widget values (scalars) and connections (arrays)
27- Connections use the format `["sourceNodeId", outputIndex]`, a 2-element array where:
28  - the first element is the string node ID of the source node
29  - the second element is the integer index into the source node's `output` list (0-based)
30- `_meta` is optional and used for display titles only
31 
32### Connection Examples
33 
34```json
35"model": ["1", 0]       // Connect to node 1's first output (MODEL)
36"clip": ["1", 1]        // Connect to node 1's second output (CLIP)
37"vae": ["1", 2]         // Connect to node 1's third output (VAE)
38"positive": ["2", 0]    // Connect to node 2's first output (CONDITIONING)
39"samples": ["5", 0]     // Connect to node 5's first output (LATENT)
40"images": ["6", 0]      // Connect to node 6's first output (IMAGE)
41```
42 
43### Important: API Format vs Web UI Format
44…