Documentation Index
Fetch the complete documentation index at: https://docs.dartantic.ai/llms.txt
Use this file to discover all available pages before exploring further.
The OpenAI Responses provider exposes an image generation tool that allows you
to generate images on the provider.
Enable Image Generation
The image generation tool can be enabled via the chatModelOptions parameter of
the Agent constructor:
final agent = Agent(
'openai-responses',
chatModelOptions: const OpenAIResponsesChatModelOptions(
serverSideTools: {OpenAIServerSideTool.imageGeneration},
imageGenerationConfig: ImageGenerationConfig(
partialImages: 3,
quality: ImageGenerationQuality.low,
size: ImageGenerationSize.square256,
),
),
);
ImageGenerationConfig lets you request progressive previews (partialImages),
choose the quality profile, and select a size. Omit these values to fall back to
the provider defaults.
Streaming Previews
Partial renders arrive as base64-encoded bytes inside metadata events:
void handleMetadata(Map<String, dynamic> metadata) {
final events = metadata['image_generation'] as List?;
if (events == null) return;
for (final event in events) {
final preview = event['partial_image_b64'] as String?;
if (preview != null) {
// import 'dart:convert' to use base64Decode
final bytes = base64Decode(preview);
savePreview(bytes, event['partial_image_index'] as int);
}
}
}
response.image_generation_call.*) so
you can display progress indicators while the image renders.
Final Image
Completed images are attached to the assistant message as DataPart instances
with an image/* MIME type:
final result = await agent.send(prompt);
for (final msg in result.messages) {
for (final part in msg.parts) {
if (part is DataPart && part.mimeType.startsWith('image/')) {
saveFinalImage(part.bytes);
}
}
}
Example
