feat: Implement metadata collection and processing framework with debug node for verification

__init__.py

@@ -3,16 +3,23 @@ from .py.nodes.lora_loader import LoraManagerLoader
 from .py.nodes.trigger_word_toggle import TriggerWordToggle
 from .py.nodes.lora_stacker import LoraStacker
 from .py.nodes.save_image import SaveImage
+from .py.nodes.debug_metadata import DebugMetadata
+# Import metadata collector to install hooks on startup
+from .py.metadata_collector import init as init_metadata_collector
 
 NODE_CLASS_MAPPINGS = {
     LoraManagerLoader.NAME: LoraManagerLoader,
     TriggerWordToggle.NAME: TriggerWordToggle,
     LoraStacker.NAME: LoraStacker,
-    SaveImage.NAME: SaveImage
+    SaveImage.NAME: SaveImage,
+    DebugMetadata.NAME: DebugMetadata
 }
 
 WEB_DIRECTORY = "./web/comfyui"
 
+# Initialize metadata collector
+init_metadata_collector()
+
 # Register routes on import
 LoraManager.add_routes()
 __all__ = ['NODE_CLASS_MAPPINGS', 'WEB_DIRECTORY']

py/metadata_collector/__init__.py

@@ -0,0 +1,18 @@
+import os
+import importlib
+from .metadata_hook import MetadataHook
+from .metadata_registry import MetadataRegistry
+
+def init():
+    # Install hooks to collect metadata during execution
+    MetadataHook.install()
+    
+    # Initialize registry
+    registry = MetadataRegistry()
+    
+    print("ComfyUI Metadata Collector initialized")
+    
+def get_metadata(prompt_id=None):
+    """Helper function to get metadata from the registry"""
+    registry = MetadataRegistry()
+    return registry.get_metadata(prompt_id)

py/metadata_collector/metadata_hook.py

@@ -0,0 +1,123 @@
+import sys
+import inspect
+from .metadata_registry import MetadataRegistry
+
+class MetadataHook:
+    """Install hooks for metadata collection"""
+    
+    @staticmethod
+    def install():
+        """Install hooks to collect metadata during execution"""
+        try:
+            # Import ComfyUI's execution module
+            execution = None
+            try:
+                # Try direct import first
+                import execution # type: ignore
+            except ImportError:
+                # Try to locate from system modules
+                for module_name in sys.modules:
+                    if module_name.endswith('.execution'):
+                        execution = sys.modules[module_name]
+                        break
+                    
+            # If we can't find the execution module, we can't install hooks
+            if execution is None:
+                print("Could not locate ComfyUI execution module, metadata collection disabled")
+                return
+            
+            # Store the original _map_node_over_list function
+            original_map_node_over_list = execution._map_node_over_list
+            
+            # Define the wrapped _map_node_over_list function
+            def map_node_over_list_with_metadata(obj, input_data_all, func, allow_interrupt=False, execution_block_cb=None, pre_execute_cb=None):
+                # Only collect metadata when calling the main function of nodes
+                if func == obj.FUNCTION and hasattr(obj, '__class__'):
+                    try:
+                        # Get the current prompt_id from the registry
+                        registry = MetadataRegistry()
+                        prompt_id = registry.current_prompt_id
+                        
+                        if prompt_id is not None:
+                            # Get node class type
+                            class_type = obj.__class__.__name__
+                            
+                            # Unique ID might be available through the obj if it has a unique_id field
+                            node_id = getattr(obj, 'unique_id', None)
+                            if node_id is None and pre_execute_cb:
+                                # Try to extract node_id through reflection on GraphBuilder.set_default_prefix
+                                frame = inspect.currentframe()
+                                while frame:
+                                    if 'unique_id' in frame.f_locals:
+                                        node_id = frame.f_locals['unique_id']
+                                        break
+                                    frame = frame.f_back
+                            
+                            # Record inputs before execution
+                            if node_id is not None:
+                                registry.record_node_execution(node_id, class_type, input_data_all, None)
+                    except Exception as e:
+                        print(f"Error collecting metadata (pre-execution): {str(e)}")
+                
+                # Execute the original function
+                results = original_map_node_over_list(obj, input_data_all, func, allow_interrupt, execution_block_cb, pre_execute_cb)
+                
+                # After execution, collect outputs for relevant nodes
+                if func == obj.FUNCTION and hasattr(obj, '__class__'):
+                    try:
+                        # Get the current prompt_id from the registry
+                        registry = MetadataRegistry()
+                        prompt_id = registry.current_prompt_id
+                        
+                        if prompt_id is not None:
+                            # Get node class type
+                            class_type = obj.__class__.__name__
+                            
+                            # Unique ID might be available through the obj if it has a unique_id field
+                            node_id = getattr(obj, 'unique_id', None)
+                            if node_id is None and pre_execute_cb:
+                                # Try to extract node_id through reflection
+                                frame = inspect.currentframe()
+                                while frame:
+                                    if 'unique_id' in frame.f_locals:
+                                        node_id = frame.f_locals['unique_id']
+                                        break
+                                    frame = frame.f_back
+                            
+                            # Record outputs after execution
+                            if node_id is not None:
+                                registry.update_node_execution(node_id, class_type, results)
+                    except Exception as e:
+                        print(f"Error collecting metadata (post-execution): {str(e)}")
+                
+                return results
+                
+            # Also hook the execute function to track the current prompt_id
+            original_execute = execution.execute
+            
+            def execute_with_prompt_tracking(*args, **kwargs):
+                if len(args) >= 7:  # Check if we have enough arguments
+                    server, prompt, caches, node_id, extra_data, executed, prompt_id = args[:7]
+                    registry = MetadataRegistry()
+                    
+                    # Start collection if this is a new prompt
+                    if not registry.current_prompt_id or registry.current_prompt_id != prompt_id:
+                        registry.start_collection(prompt_id)
+                        
+                    # Store the dynprompt reference for node lookups
+                    if hasattr(prompt, 'original_prompt'):
+                        registry.set_current_prompt(prompt)
+                
+                # Execute the original function
+                return original_execute(*args, **kwargs)
+                
+            # Replace the functions
+            execution._map_node_over_list = map_node_over_list_with_metadata
+            execution.execute = execute_with_prompt_tracking
+            # Make map_node_over_list public to avoid it being hidden by hooks
+            execution.map_node_over_list = original_map_node_over_list
+            
+            print("Metadata collection hooks installed for runtime values")
+            
+        except Exception as e:
+            print(f"Error installing metadata hooks: {str(e)}")

py/metadata_collector/metadata_processor.py

@@ -0,0 +1,171 @@
+import json
+
+class MetadataProcessor:
+    """Process and format collected metadata"""
+    
+    @staticmethod
+    def find_primary_sampler(metadata):
+        """Find the primary KSampler node (with denoise=1)"""
+        primary_sampler = None
+        primary_sampler_id = None
+        
+        for node_id, sampler_info in metadata.get("sampling", {}).items():
+            parameters = sampler_info.get("parameters", {})
+            denoise = parameters.get("denoise")
+            
+            # If denoise is 1.0, this is likely the primary sampler
+            if denoise == 1.0 or denoise == 1:
+                primary_sampler = sampler_info
+                primary_sampler_id = node_id
+                break
+                
+        return primary_sampler_id, primary_sampler
+    
+    @staticmethod
+    def trace_node_input(prompt, node_id, input_name):
+        """Trace an input connection from a node to find the source node"""
+        if not prompt or not prompt.original_prompt or node_id not in prompt.original_prompt:
+            return None
+            
+        node_inputs = prompt.original_prompt[node_id].get("inputs", {})
+        if input_name not in node_inputs:
+            return None
+            
+        input_value = node_inputs[input_name]
+        # Input connections are formatted as [node_id, output_index]
+        if isinstance(input_value, list) and len(input_value) >= 2:
+            return input_value[0]  # Return connected node_id
+            
+        return None
+    
+    @staticmethod
+    def find_primary_checkpoint(metadata):
+        """Find the primary checkpoint model in the workflow"""
+        if not metadata.get("models"):
+            return None
+            
+        # In most workflows, there's only one checkpoint, so we can just take the first one
+        for node_id, model_info in metadata.get("models", {}).items():
+            if model_info.get("type") == "checkpoint":
+                return model_info.get("name")
+                
+        return None
+    
+    @staticmethod
+    def extract_generation_params(metadata):
+        """Extract generation parameters from metadata using node relationships"""
+        params = {
+            "prompt": "",
+            "negative_prompt": "",
+            "seed": None,
+            "steps": None,
+            "cfg_scale": None,
+            "sampler": None,
+            "checkpoint": None,
+            "loras": "",
+            "size": None,
+            "clip_skip": None
+        }
+        
+        # Get the prompt object for node relationship tracing
+        prompt = metadata.get("current_prompt")
+        
+        # Find the primary KSampler node
+        primary_sampler_id, primary_sampler = MetadataProcessor.find_primary_sampler(metadata)
+        
+        # Directly get checkpoint from metadata instead of tracing
+        checkpoint = MetadataProcessor.find_primary_checkpoint(metadata)
+        if checkpoint:
+            params["checkpoint"] = checkpoint
+        
+        if primary_sampler:
+            # Extract sampling parameters
+            sampling_params = primary_sampler.get("parameters", {})
+            params["seed"] = sampling_params.get("seed")
+            params["steps"] = sampling_params.get("steps")
+            params["cfg_scale"] = sampling_params.get("cfg")
+            params["sampler"] = sampling_params.get("sampler_name")
+            
+            # Trace connections from the primary sampler
+            if prompt and primary_sampler_id:
+                # Trace positive prompt
+                positive_node_id = MetadataProcessor.trace_node_input(prompt, primary_sampler_id, "positive")
+                if positive_node_id and positive_node_id in metadata.get("prompts", {}):
+                    params["prompt"] = metadata["prompts"][positive_node_id].get("text", "")
+                
+                # Trace negative prompt
+                negative_node_id = MetadataProcessor.trace_node_input(prompt, primary_sampler_id, "negative")
+                if negative_node_id and negative_node_id in metadata.get("prompts", {}):
+                    params["negative_prompt"] = metadata["prompts"][negative_node_id].get("text", "")
+                
+                # Check if the sampler itself has size information (from latent_image)
+                if primary_sampler_id in metadata.get("size", {}):
+                    width = metadata["size"][primary_sampler_id].get("width")
+                    height = metadata["size"][primary_sampler_id].get("height")
+                    if width and height:
+                        params["size"] = f"{width}x{height}"
+                else:
+                    # Fallback to the previous trace method if needed
+                    latent_node_id = MetadataProcessor.trace_node_input(prompt, primary_sampler_id, "latent_image")
+                    if latent_node_id:
+                        # Follow chain to find EmptyLatentImage node
+                        size_found = False
+                        current_node_id = latent_node_id
+                        
+                        # Limit depth to avoid infinite loops in complex workflows
+                        max_depth = 10
+                        for _ in range(max_depth):
+                            if current_node_id in metadata.get("size", {}):
+                                width = metadata["size"][current_node_id].get("width")
+                                height = metadata["size"][current_node_id].get("height")
+                                if width and height:
+                                    params["size"] = f"{width}x{height}"
+                                    size_found = True
+                                    break
+                            
+                            # Try to follow the chain
+                            if prompt and prompt.original_prompt and current_node_id in prompt.original_prompt:
+                                node_info = prompt.original_prompt[current_node_id]
+                                if "inputs" in node_info:
+                                    # Look for a connection that might lead to size information
+                                    for input_name, input_value in node_info["inputs"].items():
+                                        if isinstance(input_value, list) and len(input_value) >= 2:
+                                            current_node_id = input_value[0]
+                                            break
+                                    else:
+                                        break  # No connections to follow
+                                else:
+                                    break  # No inputs to follow
+                            else:
+                                break  # Can't follow further
+        
+        # Extract LoRAs
+        lora_parts = []
+        for node_id, lora_info in metadata.get("loras", {}).items():
+            name = lora_info.get("name", "unknown")
+            strength = lora_info.get("strength_model", 1.0)
+            lora_parts.append(f"<lora:{name}:{strength}>")
+        params["loras"] = " ".join(lora_parts)
+        
+        # Set default clip_skip value
+        params["clip_skip"] = "1"  # Common default
+        
+        return params
+    
+    @staticmethod
+    def to_comfyui_format(metadata):
+        """Convert extracted metadata to the ComfyUI output.json format"""           
+        params = MetadataProcessor.extract_generation_params(metadata)
+        
+        # Convert all values to strings to match output.json format
+        for key in params:
+            if params[key] is not None:
+                params[key] = str(params[key])
+        
+        return params
+    
+    @staticmethod
+    def to_json(metadata):
+        """Convert metadata to JSON string"""
+        params = MetadataProcessor.to_comfyui_format(metadata)
+        return json.dumps(params, indent=4)

py/metadata_collector/metadata_registry.py

@@ -0,0 +1,171 @@
+import time
+from .node_extractors import NODE_EXTRACTORS, GenericNodeExtractor
+
+class MetadataRegistry:
+    """A singleton registry to store and retrieve workflow metadata"""
+    _instance = None
+    
+    def __new__(cls):
+        if cls._instance is None:
+            cls._instance = super().__new__(cls)
+            cls._instance._reset()
+        return cls._instance
+    
+    def _reset(self):
+        self.current_prompt_id = None
+        self.current_prompt = None
+        self.metadata = {}
+        self.prompt_metadata = {}
+        self.executed_nodes = set()
+        
+        # Node-level cache for metadata
+        self.node_cache = {}
+        
+        # Categories we want to track and retrieve from cache
+        self.metadata_categories = ["models", "prompts", "sampling", "loras", "size"]
+    
+    def start_collection(self, prompt_id):
+        """Begin metadata collection for a new prompt"""
+        self.current_prompt_id = prompt_id
+        self.executed_nodes = set()
+        self.prompt_metadata[prompt_id] = {
+            "models": {},
+            "prompts": {},
+            "sampling": {},
+            "loras": {},
+            "size": {},
+            "execution_order": [],
+            "current_prompt": None,  # Will store the prompt object
+            "timestamp": time.time()
+        }
+    
+    def set_current_prompt(self, prompt):
+        """Set the current prompt object reference"""
+        self.current_prompt = prompt
+        if self.current_prompt_id and self.current_prompt_id in self.prompt_metadata:
+            # Store the prompt in the metadata for later relationship tracing
+            self.prompt_metadata[self.current_prompt_id]["current_prompt"] = prompt
+        
+    def get_metadata(self, prompt_id=None):
+        """Get collected metadata for a prompt"""
+        key = prompt_id if prompt_id is not None else self.current_prompt_id
+        if key not in self.prompt_metadata:
+            return {}
+            
+        metadata = self.prompt_metadata[key]
+        
+        # If we have a current prompt object, check for non-executed nodes
+        prompt_obj = metadata.get("current_prompt")
+        if prompt_obj and hasattr(prompt_obj, "original_prompt"):
+            original_prompt = prompt_obj.original_prompt
+            
+            # Fill in missing metadata from cache for nodes that weren't executed
+            self._fill_missing_metadata(key, original_prompt)
+            
+        return self.prompt_metadata.get(key, {})
+    
+    def _fill_missing_metadata(self, prompt_id, original_prompt):
+        """Fill missing metadata from cache for non-executed nodes"""
+        if not original_prompt:
+            return
+            
+        executed_nodes = self.executed_nodes
+        metadata = self.prompt_metadata[prompt_id]
+        
+        # Iterate through nodes in the original prompt
+        for node_id, node_data in original_prompt.items():
+            # Skip if already executed in this run
+            if node_id in executed_nodes:
+                continue
+                
+            class_type = node_data.get("class_type")
+            if not class_type:
+                continue
+                
+            # Create cache key
+            cache_key = f"{node_id}:{class_type}"
+            
+            # Check if this node type is relevant for metadata collection
+            if class_type in NODE_EXTRACTORS:
+                # Check if we have cached metadata for this node
+                if cache_key in self.node_cache:
+                    cached_data = self.node_cache[cache_key]
+                    
+                    # Apply cached metadata to the current metadata
+                    for category in self.metadata_categories:
+                        if category in cached_data and node_id in cached_data[category]:
+                            if node_id not in metadata[category]:
+                                metadata[category][node_id] = cached_data[category][node_id]
+    
+    def record_node_execution(self, node_id, class_type, inputs, outputs):
+        """Record information about a node's execution"""
+        if not self.current_prompt_id:
+            return
+            
+        # Add to execution order and mark as executed
+        if node_id not in self.executed_nodes:
+            self.executed_nodes.add(node_id)
+            self.prompt_metadata[self.current_prompt_id]["execution_order"].append(node_id)
+        
+        # Process inputs to simplify working with them
+        processed_inputs = {}
+        for input_name, input_values in inputs.items():
+            if isinstance(input_values, list) and len(input_values) > 0:
+                # For single values, just use the first one (most common case)
+                processed_inputs[input_name] = input_values[0]
+            else:
+                processed_inputs[input_name] = input_values
+            
+        # Extract node-specific metadata
+        extractor = NODE_EXTRACTORS.get(class_type, GenericNodeExtractor)
+        extractor.extract(
+            node_id, 
+            processed_inputs, 
+            outputs, 
+            self.prompt_metadata[self.current_prompt_id]
+        )
+        
+        # Cache this node's metadata
+        self._cache_node_metadata(node_id, class_type)
+    
+    def update_node_execution(self, node_id, class_type, outputs):
+        """Update node metadata with output information"""
+        if not self.current_prompt_id:
+            return
+        
+        # Process outputs to make them more usable
+        processed_outputs = outputs
+            
+        # Use the same extractor to update with outputs
+        extractor = NODE_EXTRACTORS.get(class_type, GenericNodeExtractor)
+        if hasattr(extractor, 'update'):
+            extractor.update(
+                node_id, 
+                processed_outputs, 
+                self.prompt_metadata[self.current_prompt_id]
+            )
+            
+        # Update the cached metadata for this node
+        self._cache_node_metadata(node_id, class_type)
+            
+    def _cache_node_metadata(self, node_id, class_type):
+        """Cache the metadata for a specific node"""
+        if not self.current_prompt_id or not node_id or not class_type:
+            return
+            
+        # Create a cache key combining node_id and class_type
+        cache_key = f"{node_id}:{class_type}"
+        
+        # Create a shallow copy of the node's metadata
+        node_metadata = {}
+        current_metadata = self.prompt_metadata[self.current_prompt_id]
+        
+        for category in self.metadata_categories:
+            if category in current_metadata and node_id in current_metadata[category]:
+                if category not in node_metadata:
+                    node_metadata[category] = {}
+                node_metadata[category][node_id] = current_metadata[category][node_id]
+        
+        # Save to cache if we have any metadata for this node
+        if any(node_metadata.values()):
+            self.node_cache[cache_key] = node_metadata

py/metadata_collector/node_extractors.py

@@ -0,0 +1,163 @@
+class NodeMetadataExtractor:
+    """Base class for node-specific metadata extraction"""
+    
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        """Extract metadata from node inputs/outputs"""
+        pass
+        
+    @staticmethod
+    def update(node_id, outputs, metadata):
+        """Update metadata with node outputs after execution"""
+        pass
+        
+class GenericNodeExtractor(NodeMetadataExtractor):
+    """Default extractor for nodes without specific handling"""
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        pass
+        
+class CheckpointLoaderExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs or "ckpt_name" not in inputs:
+            return
+            
+        model_name = inputs.get("ckpt_name")
+        if model_name:
+            metadata["models"][node_id] = {
+                "name": model_name,
+                "type": "checkpoint",
+                "node_id": node_id
+            }
+        
+class CLIPTextEncodeExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs or "text" not in inputs:
+            return
+            
+        text = inputs.get("text", "")
+        metadata["prompts"][node_id] = {
+            "text": text,
+            "node_id": node_id
+        }
+        
+class SamplerExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs:
+            return
+            
+        sampling_params = {}
+        for key in ["seed", "steps", "cfg", "sampler_name", "scheduler", "denoise"]:
+            if key in inputs:
+                sampling_params[key] = inputs[key]
+                
+        metadata["sampling"][node_id] = {
+            "parameters": sampling_params,
+            "node_id": node_id
+        }
+        
+        # Extract latent image dimensions if available
+        if "latent_image" in inputs and inputs["latent_image"] is not None:
+            latent = inputs["latent_image"]
+            if isinstance(latent, dict) and "samples" in latent:
+                # Extract dimensions from latent tensor
+                samples = latent["samples"]
+                if hasattr(samples, "shape") and len(samples.shape) >= 3:
+                    # Correct shape interpretation: [batch_size, channels, height/8, width/8]
+                    # Multiply by 8 to get actual pixel dimensions
+                    height = int(samples.shape[2] * 8)
+                    width = int(samples.shape[3] * 8)
+                    
+                    if "size" not in metadata:
+                        metadata["size"] = {}
+                        
+                    metadata["size"][node_id] = {
+                        "width": width,
+                        "height": height,
+                        "node_id": node_id
+                    }
+
+class LoraLoaderExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs or "lora_name" not in inputs:
+            return
+            
+        lora_name = inputs.get("lora_name")
+        strength_model = inputs.get("strength_model", 1.0)
+        strength_clip = inputs.get("strength_clip", 1.0)
+        
+        metadata["loras"][node_id] = {
+            "name": lora_name,
+            "strength_model": strength_model,
+            "strength_clip": strength_clip,
+            "node_id": node_id
+        }
+
+class ImageSizeExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs:
+            return
+        
+        width = inputs.get("width", 512)
+        height = inputs.get("height", 512)
+        
+        if "size" not in metadata:
+            metadata["size"] = {}
+            
+        metadata["size"][node_id] = {
+            "width": width,
+            "height": height,
+            "node_id": node_id
+        }
+
+class LoraLoaderManagerExtractor(NodeMetadataExtractor):
+    @staticmethod
+    def extract(node_id, inputs, outputs, metadata):
+        if not inputs:
+            return
+            
+        # Handle LoraManager nodes which might store loras differently
+        if "loras" in inputs:
+            loras = inputs.get("loras", [])
+            if isinstance(loras, list):
+                active_loras = []
+                # Filter for active loras (may be a list of dicts with 'active' flag)
+                for lora in loras:
+                    if isinstance(lora, dict) and lora.get("active", True) and not lora.get("_isDummy", False):
+                        active_loras.append({
+                            "name": lora.get("name", ""),
+                            "strength": lora.get("strength", 1.0)
+                        })
+                
+                if active_loras:
+                    metadata["loras"][node_id] = {
+                        "lora_list": active_loras,
+                        "node_id": node_id
+                    }
+        
+        # If there's a direct text field with lora definitions
+        if "text" in inputs:
+            text = inputs.get("text", "")
+            if text and "<lora:" in text:
+                metadata["loras"][node_id] = {
+                    "raw_text": text,
+                    "node_id": node_id
+                }
+        
+# Registry of node-specific extractors
+NODE_EXTRACTORS = {
+    "CheckpointLoaderSimple": CheckpointLoaderExtractor,
+    "CLIPTextEncode": CLIPTextEncodeExtractor,
+    "KSampler": SamplerExtractor,
+    "LoraLoader": LoraLoaderExtractor,
+    "EmptyLatentImage": ImageSizeExtractor,
+    "Lora Loader (LoraManager)": LoraLoaderManagerExtractor,
+    "SamplerCustomAdvanced": SamplerExtractor,  # Add SamplerCustomAdvanced
+    "UNETLoader": CheckpointLoaderExtractor,    # Add UNETLoader
+    # Add other nodes as needed
+}

py/nodes/debug_metadata.py

@@ -0,0 +1,35 @@
+import logging
+from ..metadata_collector.metadata_processor import MetadataProcessor
+
+logger = logging.getLogger(__name__)
+
+class DebugMetadata:
+    NAME = "Debug Metadata (LoraManager)"
+    CATEGORY = "Lora Manager/utils"
+    DESCRIPTION = "Debug node to verify metadata_processor functionality"
+    
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "images": ("IMAGE",),
+            },
+        }
+
+    RETURN_TYPES = ("STRING",)
+    RETURN_NAMES = ("metadata_json",)
+    FUNCTION = "process_metadata"
+
+    def process_metadata(self, images):
+        try:
+            # Get the current execution context's metadata
+            from ..metadata_collector import get_metadata
+            metadata = get_metadata()
+            
+            # Use the MetadataProcessor to convert it to JSON string
+            metadata_json = MetadataProcessor.to_json(metadata)
+            
+            return (metadata_json,)
+        except Exception as e:
+            logger.error(f"Error processing metadata: {e}")
+            return ("{}",)  # Return empty JSON object in case of error