Merge branch 'main' into modular-workflow

src/diffusers/modular_pipelines/modular_pipeline.py

@@ -39,8 +39,11 @@ from .modular_pipeline_utils import (
     InputParam,
     InsertableDict,
     OutputParam,
+    combine_inputs,
+    combine_outputs,
     format_components,
     format_configs,
+    format_workflow,
     make_doc_string,
 )
 
@@ -243,6 +246,7 @@ class ModularPipelineBlocks(ConfigMixin, PushToHubMixin):
 
     config_name = "modular_config.json"
     model_name = None
+    _workflow_map = None
 
     @classmethod
     def _get_signature_keys(cls, obj):
@@ -298,6 +302,35 @@ class ModularPipelineBlocks(ConfigMixin, PushToHubMixin):
     def outputs(self) -> List[OutputParam]:
         return self._get_outputs()
 
+    # currentlyonly ConditionalPipelineBlocks and SequentialPipelineBlocks support `get_execution_blocks`
+    def get_execution_blocks(self, **kwargs):
+        """
+        Get the block(s) that would execute given the inputs. Must be implemented by subclasses that support
+        conditional block selection.
+
+        Args:
+            **kwargs: Input names and values. Only trigger inputs affect block selection.
+        """
+        raise NotImplementedError(f"`get_execution_blocks` is not implemented for {self.__class__.__name__}")
+
+    # currently only SequentialPipelineBlocks support workflows
+    @property
+    def workflow_names(self):
+        """
+        Returns a list of available workflow names. Must be implemented by subclasses that define `_workflow_map`.
+        """
+        raise NotImplementedError(f"`workflow_names` is not implemented for {self.__class__.__name__}")
+
+    def get_workflow(self, workflow_name: str):
+        """
+        Get the execution blocks for a specific workflow. Must be implemented by subclasses that define
+        `_workflow_map`.
+
+        Args:
+            workflow_name: Name of the workflow to retrieve.
+        """
+        raise NotImplementedError(f"`get_workflow` is not implemented for {self.__class__.__name__}")
+
     @classmethod
     def from_pretrained(
         cls,
@@ -435,72 +468,6 @@ class ModularPipelineBlocks(ConfigMixin, PushToHubMixin):
                     if current_value is not param:  # Using identity comparison to check if object was modified
                         state.set(param_name, param, input_param.kwargs_type)
 
-    @staticmethod
-    def combine_inputs(*named_input_lists: List[Tuple[str, List[InputParam]]]) -> List[InputParam]:
-        """
-        Combines multiple lists of InputParam objects from different blocks. For duplicate inputs, updates only if
-        current default value is None and new default value is not None. Warns if multiple non-None default values
-        exist for the same input.
-
-        Args:
-            named_input_lists: List of tuples containing (block_name, input_param_list) pairs
-
-        Returns:
-            List[InputParam]: Combined list of unique InputParam objects
-        """
-        combined_dict = {}  # name -> InputParam
-        value_sources = {}  # name -> block_name
-
-        for block_name, inputs in named_input_lists:
-            for input_param in inputs:
-                if input_param.name is None and input_param.kwargs_type is not None:
-                    input_name = "*_" + input_param.kwargs_type
-                else:
-                    input_name = input_param.name
-                if input_name in combined_dict:
-                    current_param = combined_dict[input_name]
-                    if (
-                        current_param.default is not None
-                        and input_param.default is not None
-                        and current_param.default != input_param.default
-                    ):
-                        warnings.warn(
-                            f"Multiple different default values found for input '{input_name}': "
-                            f"{current_param.default} (from block '{value_sources[input_name]}') and "
-                            f"{input_param.default} (from block '{block_name}'). Using {current_param.default}."
-                        )
-                    if current_param.default is None and input_param.default is not None:
-                        combined_dict[input_name] = input_param
-                        value_sources[input_name] = block_name
-                else:
-                    combined_dict[input_name] = input_param
-                    value_sources[input_name] = block_name
-
-        return list(combined_dict.values())
-
-    @staticmethod
-    def combine_outputs(*named_output_lists: List[Tuple[str, List[OutputParam]]]) -> List[OutputParam]:
-        """
-        Combines multiple lists of OutputParam objects from different blocks. For duplicate outputs, keeps the first
-        occurrence of each output name.
-
-        Args:
-            named_output_lists: List of tuples containing (block_name, output_param_list) pairs
-
-        Returns:
-            List[OutputParam]: Combined list of unique OutputParam objects
-        """
-        combined_dict = {}  # name -> OutputParam
-
-        for block_name, outputs in named_output_lists:
-            for output_param in outputs:
-                if (output_param.name not in combined_dict) or (
-                    combined_dict[output_param.name].kwargs_type is None and output_param.kwargs_type is not None
-                ):
-                    combined_dict[output_param.name] = output_param
-
-        return list(combined_dict.values())
-
     @property
     def input_names(self) -> List[str]:
         return [input_param.name for input_param in self.inputs if input_param.name is not None]
@@ -532,7 +499,8 @@ class ModularPipelineBlocks(ConfigMixin, PushToHubMixin):
 class ConditionalPipelineBlocks(ModularPipelineBlocks):
     """
     A Pipeline Blocks that conditionally selects a block to run based on the inputs. Subclasses must implement the
-    `select_block` method to define the logic for selecting the block.
+    `select_block` method to define the logic for selecting the block. Currently, we only support selection logic based
+    on the presence or absence of inputs (i.e., whether they are `None` or not)
 
     This class inherits from [`ModularPipelineBlocks`]. Check the superclass documentation for the generic methods the
     library implements for all the pipeline blocks (such as loading or saving etc.)
@@ -540,15 +508,20 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
     > [!WARNING] > This is an experimental feature and is likely to change in the future.
 
     Attributes:
-        block_classes: List of block classes to be used
-        block_names: List of prefixes for each block
-        block_trigger_inputs: List of input names that select_block() uses to determine which block to run
+        block_classes: List of block classes to be used. Must have the same length as `block_names`.
+        block_names: List of names for each block. Must have the same length as `block_classes`.
+        block_trigger_inputs: List of input names that `select_block()` uses to determine which block to run.
+            For `ConditionalPipelineBlocks`, this does not need to correspond to `block_names` and `block_classes`. For
+            `AutoPipelineBlocks`, this must have the same length as `block_names` and `block_classes`, where each
+            element specifies the trigger input for the corresponding block.
+        default_block_name: Name of the default block to run when no trigger inputs match.
+            If None, this block can be skipped entirely when no trigger inputs are provided.
     """
 
     block_classes = []
     block_names = []
     block_trigger_inputs = []
-    default_block_name = None  # name of the default block if no trigger inputs are provided, if None, this block can be skipped if no trigger inputs are provided
+    default_block_name = None
 
     def __init__(self):
         sub_blocks = InsertableDict()
@@ -612,7 +585,7 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
     @property
     def inputs(self) -> List[Tuple[str, Any]]:
         named_inputs = [(name, block.inputs) for name, block in self.sub_blocks.items()]
-        combined_inputs = self.combine_inputs(*named_inputs)
+        combined_inputs = combine_inputs(*named_inputs)
         # mark Required inputs only if that input is required by all the blocks
         for input_param in combined_inputs:
             if input_param.name in self.required_inputs:
@@ -624,15 +597,16 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
     @property
     def intermediate_outputs(self) -> List[str]:
         named_outputs = [(name, block.intermediate_outputs) for name, block in self.sub_blocks.items()]
-        combined_outputs = self.combine_outputs(*named_outputs)
+        combined_outputs = combine_outputs(*named_outputs)
         return combined_outputs
 
     @property
     def outputs(self) -> List[str]:
         named_outputs = [(name, block.outputs) for name, block in self.sub_blocks.items()]
-        combined_outputs = self.combine_outputs(*named_outputs)
+        combined_outputs = combine_outputs(*named_outputs)
         return combined_outputs
 
+    # used for `__repr__`
     def _get_trigger_inputs(self) -> set:
         """
         Returns a set of all unique trigger input values found in this block and nested blocks.
@@ -661,11 +635,6 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
 
         return all_triggers
 
-    @property
-    def trigger_inputs(self):
-        """All trigger inputs including from nested blocks."""
-        return self._get_trigger_inputs()
-
     def select_block(self, **kwargs) -> Optional[str]:
         """
         Select the block to run based on the trigger inputs. Subclasses must implement this method to define the logic
@@ -705,6 +674,39 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
             logger.error(error_msg)
             raise
 
+    def get_execution_blocks(self, **kwargs) -> Optional["ModularPipelineBlocks"]:
+        """
+        Get the block(s) that would execute given the inputs.
+
+        Recursively resolves nested ConditionalPipelineBlocks until reaching either:
+        - A leaf block (no sub_blocks) → returns single `ModularPipelineBlocks`
+        - A `SequentialPipelineBlocks` → delegates to its `get_execution_blocks()` which returns
+        a `SequentialPipelineBlocks` containing the resolved execution blocks
+
+        Args:
+            **kwargs: Input names and values. Only trigger inputs affect block selection.
+
+        Returns:
+            - `ModularPipelineBlocks`: A leaf block or resolved `SequentialPipelineBlocks`
+            - `None`: If this block would be skipped (no trigger matched and no default)
+        """
+        trigger_kwargs = {name: kwargs.get(name) for name in self.block_trigger_inputs if name is not None}
+        block_name = self.select_block(**trigger_kwargs)
+
+        if block_name is None:
+            block_name = self.default_block_name
+
+        if block_name is None:
+            return None
+
+        block = self.sub_blocks[block_name]
+
+        # Recursively resolve until we hit a leaf block or a SequentialPipelineBlocks
+        if block.sub_blocks:
+            return block.get_execution_blocks(**kwargs)
+
+        return block
+
     def __repr__(self):
         class_name = self.__class__.__name__
         base_class = self.__class__.__bases__[0].__name__
@@ -712,11 +714,11 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
             f"{class_name}(\n  Class: {base_class}\n" if base_class and base_class != "object" else f"{class_name}(\n"
         )
 
-        if self.trigger_inputs:
+        if self._get_trigger_inputs():
             header += "\n"
             header += "  " + "=" * 100 + "\n"
             header += "  This pipeline contains blocks that are selected at runtime based on inputs.\n"
-            header += f"  Trigger Inputs: {sorted(self.trigger_inputs)}\n"
+            header += f"  Trigger Inputs: {sorted(self._get_trigger_inputs())}\n"
             header += "  " + "=" * 100 + "\n\n"
 
         # Format description with proper indentation
@@ -783,24 +785,56 @@ class ConditionalPipelineBlocks(ModularPipelineBlocks):
 
 class AutoPipelineBlocks(ConditionalPipelineBlocks):
     """
-    A Pipeline Blocks that automatically selects a block to run based on the presence of trigger inputs.
+        A Pipeline Blocks that automatically selects a block to run based on the presence of trigger inputs.
+
+        This is a specialized version of `ConditionalPipelineBlocks` where:
+        - Each block has one corresponding trigger input (1:1 mapping)
+        - Block selection is automatic: the first block whose trigger input is present gets selected
+        - `block_trigger_inputs` must have the same length as `block_names` and `block_classes`
+        - Use `None` in `block_trigger_inputs` to specify the default block, i.e the block that will run if no trigger
+          inputs are present
+
+        Attributes:
+            block_classes:
+                List of block classes to be used. Must have the same length as `block_names` and
+                `block_trigger_inputs`.
+            block_names:
+                List of names for each block. Must have the same length as `block_classes` and `block_trigger_inputs`.
+            block_trigger_inputs:
+                List of input names where each element specifies the trigger input for the corresponding block. Use
+                `None` to mark the default block.
+
+        Example:
+    ```python
+        class MyAutoBlock(AutoPipelineBlocks):
+            block_classes = [InpaintEncoderBlock, ImageEncoderBlock, TextEncoderBlock]
+            block_names = ["inpaint", "img2img", "text2img"]
+            block_trigger_inputs = ["mask_image", "image", None]  # text2img is the default
+    ```
+
+        With this definition:
+        - As long as `mask_image` is provided, "inpaint" block runs (regardless of `image` being provided or not)
+        - If `mask_image` is not provided but `image` is provided, "img2img" block runs
+        - Otherwise, "text2img" block runs (default, trigger is `None`)
     """
 
     def __init__(self):
         super().__init__()
 
+        if self.default_block_name is not None:
+            raise ValueError(
+                f"In {self.__class__.__name__}, do not set `default_block_name` for AutoPipelineBlocks. "
+                f"Use `None` in `block_trigger_inputs` to specify the default block."
+            )
+
         if not (len(self.block_classes) == len(self.block_names) == len(self.block_trigger_inputs)):
             raise ValueError(
                 f"In {self.__class__.__name__}, the number of block_classes, block_names, and block_trigger_inputs must be the same."
             )
 
-    @property
-    def default_block_name(self) -> Optional[str]:
-        """Derive default_block_name from block_trigger_inputs (None entry)."""
         if None in self.block_trigger_inputs:
             idx = self.block_trigger_inputs.index(None)
-            return self.block_names[idx]
-        return None
+            self.default_block_name = self.block_names[idx]
 
     def select_block(self, **kwargs) -> Optional[str]:
         """Select block based on which trigger input is present (not None)."""
@@ -854,6 +888,29 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
                     expected_configs.append(config)
         return expected_configs
 
+    @property
+    def workflow_names(self):
+        if self._workflow_map is None:
+            raise NotImplementedError(
+                f"workflows is not supported because _workflow_map is not set for {self.__class__.__name__}"
+            )
+
+        return list(self._workflow_map.keys())
+
+    def get_workflow(self, workflow_name: str):
+        if self._workflow_map is None:
+            raise NotImplementedError(
+                f"workflows is not supported because _workflow_map is not set for {self.__class__.__name__}"
+            )
+
+        if workflow_name not in self._workflow_map:
+            raise ValueError(f"Workflow {workflow_name} not found in {self.__class__.__name__}")
+
+        trigger_inputs = self._workflow_map[workflow_name]
+        workflow_blocks = self.get_execution_blocks(**trigger_inputs)
+
+        return workflow_blocks
+
     @classmethod
     def from_blocks_dict(
         cls, blocks_dict: Dict[str, Any], description: Optional[str] = None
@@ -949,7 +1006,7 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
             # filter out them here so they do not end up as intermediate_outputs
             if name not in inp_names:
                 named_outputs.append((name, block.intermediate_outputs))
-        combined_outputs = self.combine_outputs(*named_outputs)
+        combined_outputs = combine_outputs(*named_outputs)
         return combined_outputs
 
     # YiYi TODO: I think we can remove the outputs property
@@ -973,6 +1030,7 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
                 raise
         return pipeline, state
 
+    # used for `trigger_inputs` property
     def _get_trigger_inputs(self):
         """
         Returns a set of all unique trigger input values found in the blocks.
@@ -996,89 +1054,50 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
 
         return fn_recursive_get_trigger(self.sub_blocks)
 
-    @property
-    def trigger_inputs(self):
-        return self._get_trigger_inputs()
-
-    def _traverse_trigger_blocks(self, active_inputs):
+    def get_execution_blocks(self, **kwargs) -> "SequentialPipelineBlocks":
         """
-        Traverse blocks and select which ones would run given the active inputs.
+        Get the blocks that would execute given the specified inputs.
 
         Args:
-            active_inputs: Dict of input names to values that are "present"
+            **kwargs: Input names and values. Only trigger inputs affect block selection.
 
         Returns:
-            OrderedDict of block_name -> block that would execute
+            SequentialPipelineBlocks containing only the blocks that would execute
         """
+        # Copy kwargs so we can add outputs as we traverse
+        active_inputs = dict(kwargs)
 
         def fn_recursive_traverse(block, block_name, active_inputs):
             result_blocks = OrderedDict()
 
             # ConditionalPipelineBlocks (includes AutoPipelineBlocks)
             if isinstance(block, ConditionalPipelineBlocks):
-                trigger_kwargs = {name: active_inputs.get(name) for name in block.block_trigger_inputs}
-                selected_block_name = block.select_block(**trigger_kwargs)
-
-                if selected_block_name is None:
-                    selected_block_name = block.default_block_name
-
-                if selected_block_name is None:
+                block = block.get_execution_blocks(**active_inputs)
+                if block is None:
                     return result_blocks
 
-                selected_block = block.sub_blocks[selected_block_name]
-
-                if selected_block.sub_blocks:
-                    result_blocks.update(fn_recursive_traverse(selected_block, block_name, active_inputs))
-                else:
-                    result_blocks[block_name] = selected_block
-                    if hasattr(selected_block, "outputs"):
-                        for out in selected_block.outputs:
-                            active_inputs[out.name] = True
-
-                return result_blocks
-
-            # SequentialPipelineBlocks or LoopSequentialPipelineBlocks
-            if block.sub_blocks:
+            # Has sub_blocks (SequentialPipelineBlocks/ConditionalPipelineBlocks)
+            if block.sub_blocks and not isinstance(block, LoopSequentialPipelineBlocks):
                 for sub_block_name, sub_block in block.sub_blocks.items():
-                    blocks_to_update = fn_recursive_traverse(sub_block, sub_block_name, active_inputs)
-                    blocks_to_update = {f"{block_name}.{k}": v for k, v in blocks_to_update.items()}
-                    result_blocks.update(blocks_to_update)
+                    nested_blocks = fn_recursive_traverse(sub_block, sub_block_name, active_inputs)
+                    nested_blocks = {f"{block_name}.{k}": v for k, v in nested_blocks.items()}
+                    result_blocks.update(nested_blocks)
             else:
+                # Leaf block: single ModularPipelineBlocks or LoopSequentialPipelineBlocks
                 result_blocks[block_name] = block
-                if hasattr(block, "outputs"):
-                    for out in block.outputs:
+                # Add outputs to active_inputs so subsequent blocks can use them as triggers
+                if hasattr(block, "intermediate_outputs"):
+                    for out in block.intermediate_outputs:
                         active_inputs[out.name] = True
 
             return result_blocks
 
         all_blocks = OrderedDict()
         for block_name, block in self.sub_blocks.items():
-            blocks_to_update = fn_recursive_traverse(block, block_name, active_inputs)
-            all_blocks.update(blocks_to_update)
-        return all_blocks
+            nested_blocks = fn_recursive_traverse(block, block_name, active_inputs)
+            all_blocks.update(nested_blocks)
 
-    def get_execution_blocks(self, **kwargs):
-        """
-        Get the blocks that would execute given the specified inputs.
-
-        Args:
-            **kwargs: Input names and values. Only trigger inputs affect block selection.
-                    Pass any inputs that would be non-None at runtime.
-
-        Returns:
-            SequentialPipelineBlocks containing only the blocks that would execute
-
-        Example:
-            # Get blocks for inpainting workflow blocks = pipeline.get_execution_blocks(prompt="a cat", mask=mask,
-            image=image)
-
-            # Get blocks for text2image workflow blocks = pipeline.get_execution_blocks(prompt="a cat")
-        """
-        # Filter out None values
-        active_inputs = {k: v for k, v in kwargs.items() if v is not None}
-
-        blocks_triggered = self._traverse_trigger_blocks(active_inputs)
-        return SequentialPipelineBlocks.from_blocks_dict(blocks_triggered)
+        return SequentialPipelineBlocks.from_blocks_dict(all_blocks)
 
     def __repr__(self):
         class_name = self.__class__.__name__
@@ -1087,18 +1106,23 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
             f"{class_name}(\n  Class: {base_class}\n" if base_class and base_class != "object" else f"{class_name}(\n"
         )
 
-        if self.trigger_inputs:
+        if self._workflow_map is None and self._get_trigger_inputs():
             header += "\n"
             header += "  " + "=" * 100 + "\n"
             header += "  This pipeline contains blocks that are selected at runtime based on inputs.\n"
-            header += f"  Trigger Inputs: {[inp for inp in self.trigger_inputs if inp is not None]}\n"
+            header += f"  Trigger Inputs: {[inp for inp in self._get_trigger_inputs() if inp is not None]}\n"
             # Get first trigger input as example
-            example_input = next(t for t in self.trigger_inputs if t is not None)
+            example_input = next(t for t in self._get_trigger_inputs() if t is not None)
             header += f"  Use `get_execution_blocks()` to see selected blocks (e.g. `get_execution_blocks({example_input}=...)`).\n"
             header += "  " + "=" * 100 + "\n\n"
 
+        description = self.description
+        if self._workflow_map is not None:
+            workflow_str = format_workflow(self._workflow_map)
+            description = f"{self.description}\n\n{workflow_str}"
+
         # Format description with proper indentation
-        desc_lines = self.description.split("\n")
+        desc_lines = description.split("\n")
         desc = []
         # First line with "Description:" label
         desc.append(f"  Description: {desc_lines[0]}")
@@ -1146,10 +1170,15 @@ class SequentialPipelineBlocks(ModularPipelineBlocks):
 
     @property
     def doc(self):
+        description = self.description
+        if self._workflow_map is not None:
+            workflow_str = format_workflow(self._workflow_map)
+            description = f"{self.description}\n\n{workflow_str}"
+
         return make_doc_string(
             self.inputs,
             self.outputs,
-            self.description,
+            description=description,
             class_name=self.__class__.__name__,
             expected_components=self.expected_components,
             expected_configs=self.expected_configs,
@@ -1282,7 +1311,7 @@ class LoopSequentialPipelineBlocks(ModularPipelineBlocks):
     @property
     def intermediate_outputs(self) -> List[str]:
         named_outputs = [(name, block.intermediate_outputs) for name, block in self.sub_blocks.items()]
-        combined_outputs = self.combine_outputs(*named_outputs)
+        combined_outputs = combine_outputs(*named_outputs)
         for output in self.loop_intermediate_outputs:
             if output.name not in {output.name for output in combined_outputs}:
                 combined_outputs.append(output)

src/diffusers/modular_pipelines/modular_pipeline_utils.py

@@ -14,9 +14,10 @@
 
 import inspect
 import re
+import warnings
 from collections import OrderedDict
 from dataclasses import dataclass, field, fields
-from typing import Any, Dict, List, Literal, Optional, Type, Union
+from typing import Any, Dict, List, Literal, Optional, Tuple, Type, Union
 
 import PIL.Image
 import torch
@@ -860,6 +861,30 @@ def format_configs(configs, indent_level=4, max_line_length=115, add_empty_lines
     return "\n".join(formatted_configs)
 
 
+def format_workflow(workflow_map):
+    """Format a workflow map into a readable string representation.
+
+    Args:
+        workflow_map: Dictionary mapping workflow names to trigger inputs
+
+    Returns:
+        A formatted string representing all workflows
+    """
+    if workflow_map is None:
+        return ""
+
+    lines = ["Supported workflows:"]
+    for workflow_name, trigger_inputs in workflow_map.items():
+        required_inputs = [k for k, v in trigger_inputs.items() if v]
+        if required_inputs:
+            inputs_str = ", ".join(f"`{t}`" for t in required_inputs)
+            lines.append(f"  - `{workflow_name}`: requires {inputs_str}")
+        else:
+            lines.append(f"  - `{workflow_name}`: default (no additional inputs required)")
+
+    return "\n".join(lines)
+
+
 def make_doc_string(
     inputs,
     outputs,
@@ -914,3 +939,69 @@ def make_doc_string(
     output += format_output_params(outputs, indent_level=2)
 
     return output
+
+
+def combine_inputs(*named_input_lists: List[Tuple[str, List[InputParam]]]) -> List[InputParam]:
+    """
+    Combines multiple lists of InputParam objects from different blocks. For duplicate inputs, updates only if current
+    default value is None and new default value is not None. Warns if multiple non-None default values exist for the
+    same input.
+
+    Args:
+        named_input_lists: List of tuples containing (block_name, input_param_list) pairs
+
+    Returns:
+        List[InputParam]: Combined list of unique InputParam objects
+    """
+    combined_dict = {}  # name -> InputParam
+    value_sources = {}  # name -> block_name
+
+    for block_name, inputs in named_input_lists:
+        for input_param in inputs:
+            if input_param.name is None and input_param.kwargs_type is not None:
+                input_name = "*_" + input_param.kwargs_type
+            else:
+                input_name = input_param.name
+            if input_name in combined_dict:
+                current_param = combined_dict[input_name]
+                if (
+                    current_param.default is not None
+                    and input_param.default is not None
+                    and current_param.default != input_param.default
+                ):
+                    warnings.warn(
+                        f"Multiple different default values found for input '{input_name}': "
+                        f"{current_param.default} (from block '{value_sources[input_name]}') and "
+                        f"{input_param.default} (from block '{block_name}'). Using {current_param.default}."
+                    )
+                if current_param.default is None and input_param.default is not None:
+                    combined_dict[input_name] = input_param
+                    value_sources[input_name] = block_name
+            else:
+                combined_dict[input_name] = input_param
+                value_sources[input_name] = block_name
+
+    return list(combined_dict.values())
+
+
+def combine_outputs(*named_output_lists: List[Tuple[str, List[OutputParam]]]) -> List[OutputParam]:
+    """
+    Combines multiple lists of OutputParam objects from different blocks. For duplicate outputs, keeps the first
+    occurrence of each output name.
+
+    Args:
+        named_output_lists: List of tuples containing (block_name, output_param_list) pairs
+
+    Returns:
+        List[OutputParam]: Combined list of unique OutputParam objects
+    """
+    combined_dict = {}  # name -> OutputParam
+
+    for block_name, outputs in named_output_lists:
+        for output_param in outputs:
+            if (output_param.name not in combined_dict) or (
+                combined_dict[output_param.name].kwargs_type is None and output_param.kwargs_type is not None
+            ):
+                combined_dict[output_param.name] = output_param
+
+    return list(combined_dict.values())

src/diffusers/modular_pipelines/qwenimage/modular_blocks_qwenimage.py

@@ -1113,10 +1113,14 @@ AUTO_BLOCKS = InsertableDict(
 class QwenImageAutoBlocks(SequentialPipelineBlocks):
     """
     Auto Modular pipeline for text-to-image, image-to-image, inpainting, and controlnet tasks using QwenImage.
-      - for image-to-image generation, you need to provide `image`
-      - for inpainting, you need to provide `mask_image` and `image`, optionally you can provide `padding_mask_crop`.
-      - to run the controlnet workflow, you need to provide `control_image`
-      - for text-to-image generation, all you need to provide is `prompt`
+
+      Supported workflows:
+        - `text2image`: requires `prompt`
+        - `image2image`: requires `prompt`, `image`
+        - `inpainting`: requires `prompt`, `mask_image`, `image`
+        - `controlnet_text2image`: requires `prompt`, `control_image`
+        - `controlnet_image2image`: requires `prompt`, `image`, `control_image`
+        - `controlnet_inpainting`: requires `prompt`, `mask_image`, `image`, `control_image`
 
       Components:
           text_encoder (`Qwen2_5_VLForConditionalGeneration`): The text encoder to use tokenizer (`Qwen2Tokenizer`):
@@ -1197,15 +1201,24 @@ class QwenImageAutoBlocks(SequentialPipelineBlocks):
     block_classes = AUTO_BLOCKS.values()
     block_names = AUTO_BLOCKS.keys()
 
+    # Workflow map defines the trigger conditions for each workflow.
+    # How to define:
+    #   - Only include required inputs and trigger inputs (inputs that determine which blocks run)
+    #   - `True` means the workflow triggers when the input is not None (most common case)
+    #   - Use specific values (e.g., `{"strength": 0.5}`) if your `select_block` logic depends on the value
+
+    _workflow_map = {
+        "text2image": {"prompt": True},
+        "image2image": {"prompt": True, "image": True},
+        "inpainting": {"prompt": True, "mask_image": True, "image": True},
+        "controlnet_text2image": {"prompt": True, "control_image": True},
+        "controlnet_image2image": {"prompt": True, "image": True, "control_image": True},
+        "controlnet_inpainting": {"prompt": True, "mask_image": True, "image": True, "control_image": True},
+    }
+
     @property
     def description(self):
-        return (
-            "Auto Modular pipeline for text-to-image, image-to-image, inpainting, and controlnet tasks using QwenImage.\n"
-            + "- for image-to-image generation, you need to provide `image`\n"
-            + "- for inpainting, you need to provide `mask_image` and `image`, optionally you can provide `padding_mask_crop`.\n"
-            + "- to run the controlnet workflow, you need to provide `control_image`\n"
-            + "- for text-to-image generation, all you need to provide is `prompt`"
-        )
+        return "Auto Modular pipeline for text-to-image, image-to-image, inpainting, and controlnet tasks using QwenImage."
 
     @property
     def outputs(self):