InvokeAI/docs/nodes/invocation-api.md

Invocation API

Each invocation's invoke method is provided a single arg - the Invocation Context.

This object provides an API the invocation can use to interact with application services, for example:

• Saving images
• Logging messages
• Loading models

class MyInvocation(BaseInvocation):
  ...
  def invoke(self, context: InvocationContext) -> ImageOutput:
      # Load an image
      image_pil = context.images.get_pil(self.image.image_name)
      # Do something to the image
      output_image = do_something_cool(image_pil)
      # Save the image
      image_dto = context.images.save(output_image)
      # Log a message
      context.logger.info(f"Did something cool, image saved!")
      # Return the output
      return ImageOutput.build(image_dto)
      ...

The full API is documented below.

Mixins

Two important mixins are provided to facilitate working with metadata and gallery boards.

WithMetadata

Inherit from this class (in addition to BaseInvocation) to add a metadata input to your node. When you do this, you can access the metadata dict from self.metadata in the invoke() function.

The dict will be populated via the node's input, and you can add any metadata you'd like to it. When you call context.images.save(), if the metadata dict has any data, it be automatically embedded in the image.

WithBoard

Inherit from this class (in addition to BaseInvocation) to add a board input to your node. This renders as a drop-down to select a board. The user's selection will be accessible from self.board in the invoke() function.

When you call context.images.save(), if a board was selected, the image will added to that board as it is saved.

::: invokeai.app.services.shared.invocation_context.InvocationContext options: members: false

::: invokeai.app.services.shared.invocation_context.ImagesInterface

::: invokeai.app.services.shared.invocation_context.TensorsInterface

::: invokeai.app.services.shared.invocation_context.ConditioningInterface

::: invokeai.app.services.shared.invocation_context.ModelsInterface

::: invokeai.app.services.shared.invocation_context.LoggerInterface

::: invokeai.app.services.shared.invocation_context.ConfigInterface

::: invokeai.app.services.shared.invocation_context.UtilInterface

::: invokeai.app.services.shared.invocation_context.BoardsInterface