{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://github.com/comfyanonymous/ComfyUI/schemas/prompt_format.json",
  "title": "ComfyUI Prompt API Format",
  "description": "JSON Schema for the ComfyUI Prompt API format used with the /prompt endpoint",
  "type": "object",
  "properties": {
    "prompt": {
      "type": "object",
      "description": "The node graph defining the workflow to execute",
      "patternProperties": {
        "^[0-9]+$": {
          "type": "object",
          "description": "Node definition with numeric ID as key",
          "properties": {
            "class_type": {
              "type": "string",
              "description": "The class name of the node (e.g., 'CheckpointLoaderSimple', 'KSampler')",
              "minLength": 1
            },
            "inputs": {
              "type": "object",
              "description": "Input values or connections for this node",
              "patternProperties": {
                ".*": {
                  "oneOf": [
                    {
                      "type": "array",
                      "description": "Connection to another node [node_id, output_slot]",
                      "prefixItems": [
                        {
                          "type": "string",
                          "description": "ID of the source node",
                          "pattern": "^[0-9]+$"
                        },
                        {
                          "type": "integer",
                          "description": "Output slot index of the source node",
                          "minimum": 0
                        }
                      ],
                      "items": false,
                      "minItems": 2,
                      "maxItems": 2
                    },
                    {
                      "not": {
                        "type": "array",
                        "minItems": 2,
                        "maxItems": 2,
                        "prefixItems": [
                          {"type": "string", "pattern": "^[0-9]+$"},
                          {"type": "integer", "minimum": 0}
                        ]
                      },
                      "description": "Direct input value (string, number, boolean, object, or array)"
                    }
                  ]
                }
              },
              "additionalProperties": true
            },
            "_meta": {
              "type": "object",
              "description": "Optional metadata for the node (not used in execution)",
              "properties": {
                "title": {
                  "type": "string",
                  "description": "Custom title for the node"
                }
              },
              "additionalProperties": true
            }
          },
          "required": ["class_type", "inputs"],
          "additionalProperties": false
        }
      },
      "additionalProperties": false,
      "minProperties": 1
    },
    "prompt_id": {
      "type": "string",
      "description": "Optional unique identifier for this prompt execution. If not provided, a UUID will be generated.",
      "pattern": "^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}$|^[a-fA-F0-9]{32}$"
    },
    "number": {
      "type": "number",
      "description": "Optional execution priority number. Lower numbers execute first."
    },
    "front": {
      "type": "boolean",
      "description": "If true, this prompt will be prioritized (given a negative number)."
    },
    "extra_data": {
      "type": "object",
      "description": "Additional metadata and configuration for the execution",
      "properties": {
        "client_id": {
          "type": "string",
          "description": "Client identifier for WebSocket communication"
        }
      },
      "additionalProperties": true
    },
    "client_id": {
      "type": "string",
      "description": "Client identifier for WebSocket communication (alternative to extra_data.client_id)"
    },
    "partial_execution_targets": {
      "type": "array",
      "description": "Optional array of node IDs to execute selectively. If provided, only these nodes (and their dependencies) will be executed.",
      "items": {
        "type": "string",
        "pattern": "^[0-9]+$",
        "description": "Node ID to execute"
      },
      "uniqueItems": true
    }
  },
  "required": ["prompt"],
  "additionalProperties": false,
  "examples": [
    {
      "prompt": {
        "1": {
          "class_type": "CheckpointLoaderSimple",
          "inputs": {
            "ckpt_name": "model.safetensors"
          }
        },
        "2": {
          "class_type": "CLIPTextEncode",
          "inputs": {
            "text": "a beautiful landscape",
            "clip": ["1", 1]
          }
        },
        "3": {
          "class_type": "CLIPTextEncode", 
          "inputs": {
            "text": "blurry, low quality",
            "clip": ["1", 1]
          }
        },
        "4": {
          "class_type": "KSampler",
          "inputs": {
            "seed": 12345,
            "steps": 20,
            "cfg": 7.0,
            "sampler_name": "euler",
            "scheduler": "normal",
            "denoise": 1.0,
            "model": ["1", 0],
            "positive": ["2", 0],
            "negative": ["3", 0],
            "latent_image": ["5", 0]
          }
        },
        "5": {
          "class_type": "EmptyLatentImage",
          "inputs": {
            "width": 512,
            "height": 512,
            "batch_size": 1
          }
        },
        "6": {
          "class_type": "VAEDecode",
          "inputs": {
            "samples": ["4", 0],
            "vae": ["1", 2]
          }
        },
        "7": {
          "class_type": "SaveImage",
          "inputs": {
            "filename_prefix": "ComfyUI",
            "images": ["6", 0]
          }
        }
      }
    },
    {
      "prompt": {
        "1": {
          "class_type": "LoadImage",
          "inputs": {
            "image": "input.png"
          }
        },
        "2": {
          "class_type": "SaveImage",
          "inputs": {
            "filename_prefix": "output",
            "images": ["1", 0]
          }
        }
      },
      "prompt_id": "550e8400-e29b-41d4-a716-446655440000",
      "client_id": "client_123"
    }
  ]
}