feat: add streaming support and new GPT-Image models for OpenAI

.github/workflows/pr-check.yml

@@ -21,6 +21,26 @@ jobs:
           distribution: 'temurin'
           cache: 'maven'
 
-      - name: Run tests
+      - name: Build spring-ai-model module
         run: |
-          ./mvnw --batch-mode test
+          ./mvnw clean install -pl spring-ai-model -DskipTests
+
+      - name: Build spring-ai-openai module
+        run: |
+          ./mvnw clean install -pl models/spring-ai-openai -DskipTests
+
+      - name: Run OpenAI Image Model integration tests
+        env:
+          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+        run: |
+          ./mvnw -pl models/spring-ai-openai -Pintegration-tests -Dit.test=OpenAiImageModelIT,OpenAiImageModelNoOpApiKeysIT,OpenAiImageModelObservationIT,OpenAiImageModelStreamingIT,OpenAiImageModelWithImageResponseMetadataTests,OpenAiImageApiBuilderTests,OpenAiImageApiIT,OpenAiImageApiStreamingIT verify
+
+      - name: Run OpenAI Image AutoConfiguration tests
+        env:
+          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
+        run: |
+          ./mvnw -pl auto-configurations/models/spring-ai-autoconfigure-model-openai -Pintegration-tests -Dit.test=OpenAiImageAutoConfigurationIT verify
+
+      - name: Run OpenAI Image Properties tests
+        run: |
+          ./mvnw test -pl auto-configurations/models/spring-ai-autoconfigure-model-openai -Dtest=OpenAiPropertiesTests#imageOptionsTest,OpenAiPropertiesTests#imageGptImageOptionsTest

auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiImageAutoConfiguration.java

@@ -23,7 +23,6 @@
 import org.springframework.ai.model.SpringAIModelProperties;
 import org.springframework.ai.model.SpringAIModels;
 import org.springframework.ai.openai.OpenAiImageModel;
-import org.springframework.ai.openai.api.OpenAiApi;
 import org.springframework.ai.openai.api.OpenAiImageApi;
 import org.springframework.ai.retry.autoconfigure.SpringAiRetryAutoConfiguration;
 import org.springframework.beans.factory.ObjectProvider;
@@ -38,6 +37,7 @@
 import org.springframework.retry.support.RetryTemplate;
 import org.springframework.web.client.ResponseErrorHandler;
 import org.springframework.web.client.RestClient;
+import org.springframework.web.reactive.function.client.WebClient;
 
 import static org.springframework.ai.model.openai.autoconfigure.OpenAIAutoConfigurationUtil.resolveConnectionProperties;
 
@@ -53,31 +53,38 @@
  */
 @AutoConfiguration(after = { RestClientAutoConfiguration.class, WebClientAutoConfiguration.class,
 		SpringAiRetryAutoConfiguration.class })
-@ConditionalOnClass(OpenAiApi.class)
+@ConditionalOnClass(OpenAiImageApi.class)
 @ConditionalOnProperty(name = SpringAIModelProperties.IMAGE_MODEL, havingValue = SpringAIModels.OPENAI,
 		matchIfMissing = true)
 @EnableConfigurationProperties({ OpenAiConnectionProperties.class, OpenAiImageProperties.class })
 public class OpenAiImageAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public OpenAiImageModel openAiImageModel(OpenAiConnectionProperties commonProperties,
+	public OpenAiImageApi openAiImageApi(OpenAiConnectionProperties commonProperties,
 			OpenAiImageProperties imageProperties, ObjectProvider<RestClient.Builder> restClientBuilderProvider,
-			RetryTemplate retryTemplate, ResponseErrorHandler responseErrorHandler,
-			ObjectProvider<ObservationRegistry> observationRegistry,
-			ObjectProvider<ImageModelObservationConvention> observationConvention) {
+			ObjectProvider<WebClient.Builder> webClientBuilderProvider, ResponseErrorHandler responseErrorHandler) {
 
 		OpenAIAutoConfigurationUtil.ResolvedConnectionProperties resolved = resolveConnectionProperties(
 				commonProperties, imageProperties, "image");
 
-		var openAiImageApi = OpenAiImageApi.builder()
+		return OpenAiImageApi.builder()
 			.baseUrl(resolved.baseUrl())
 			.apiKey(new SimpleApiKey(resolved.apiKey()))
 			.headers(resolved.headers())
 			.imagesPath(imageProperties.getImagesPath())
 			.restClientBuilder(restClientBuilderProvider.getIfAvailable(RestClient::builder))
+			.webClientBuilder(webClientBuilderProvider.getIfAvailable(WebClient::builder))
 			.responseErrorHandler(responseErrorHandler)
 			.build();
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public OpenAiImageModel openAiImageModel(OpenAiImageApi openAiImageApi, OpenAiImageProperties imageProperties,
+			RetryTemplate retryTemplate, ObjectProvider<ObservationRegistry> observationRegistry,
+			ObjectProvider<ImageModelObservationConvention> observationConvention) {
+
 		var imageModel = new OpenAiImageModel(openAiImageApi, imageProperties.getOptions(), retryTemplate,
 				observationRegistry.getIfUnique(() -> ObservationRegistry.NOOP));
 

auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiImageAutoConfigurationIT.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2023-2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.model.openai.autoconfigure;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+
+import org.springframework.ai.image.ImagePrompt;
+import org.springframework.ai.image.ImageResponse;
+import org.springframework.ai.model.tool.autoconfigure.ToolCallingAutoConfiguration;
+import org.springframework.ai.openai.OpenAiImageModel;
+import org.springframework.ai.openai.api.OpenAiImageApi;
+import org.springframework.ai.retry.autoconfigure.SpringAiRetryAutoConfiguration;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for {@link OpenAiImageAutoConfiguration}.
+ *
+ * @author Alexandros Pappas
+ * @since 1.1.0
+ */
+@EnabledIfEnvironmentVariable(named = "OPENAI_API_KEY", matches = ".+")
+public class OpenAiImageAutoConfigurationIT {
+
+	private static final Log logger = LogFactory.getLog(OpenAiImageAutoConfigurationIT.class);
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.ai.openai.apiKey=" + System.getenv("OPENAI_API_KEY"))
+		.withConfiguration(
+				AutoConfigurations.of(SpringAiRetryAutoConfiguration.class, RestClientAutoConfiguration.class,
+						WebClientAutoConfiguration.class, ToolCallingAutoConfiguration.class));
+
+	@Test
+	void imageModelAutoConfigured() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(OpenAiImageAutoConfiguration.class)).run(context -> {
+			assertThat(context.getBeansOfType(OpenAiImageModel.class)).isNotEmpty();
+			assertThat(context.getBeansOfType(OpenAiImageApi.class)).isNotEmpty();
+		});
+	}
+
+	@Test
+	void generateImage() {
+		this.contextRunner
+			.withPropertyValues("spring.ai.openai.image.options.model=dall-e-2",
+					"spring.ai.openai.image.options.response-format=b64_json")
+			.withConfiguration(AutoConfigurations.of(OpenAiImageAutoConfiguration.class))
+			.run(context -> {
+				OpenAiImageModel imageModel = context.getBean(OpenAiImageModel.class);
+				ImagePrompt prompt = new ImagePrompt("A simple red circle");
+				ImageResponse response = imageModel.call(prompt);
+
+				assertThat(response).isNotNull();
+				assertThat(response.getResults()).hasSize(1);
+				assertThat(response.getResult().getOutput().getB64Json()).isNotEmpty();
+
+				logger.info("Generated image with base64 length: "
+						+ response.getResult().getOutput().getB64Json().length());
+			});
+	}
+
+	@Test
+	void imageModelDisabled() {
+		this.contextRunner.withPropertyValues("spring.ai.model.image=none")
+			.withConfiguration(AutoConfigurations.of(OpenAiImageAutoConfiguration.class))
+			.run(context -> assertThat(context.getBeansOfType(OpenAiImageModel.class)).isEmpty());
+	}
+
+	@Test
+	void imageModelExplicitlyEnabled() {
+		this.contextRunner.withPropertyValues("spring.ai.model.image=openai")
+			.withConfiguration(AutoConfigurations.of(OpenAiImageAutoConfiguration.class))
+			.run(context -> assertThat(context.getBeansOfType(OpenAiImageModel.class)).isNotEmpty());
+	}
+
+}

auto-configurations/models/spring-ai-autoconfigure-model-openai/src/test/java/org/springframework/ai/model/openai/autoconfigure/OpenAiPropertiesTests.java

@@ -539,6 +539,46 @@ public void imageOptionsTest() {
 			});
 	}
 
+	@Test
+	public void imageGptImageOptionsTest() {
+		this.contextRunner.withPropertyValues(
+		// @formatter:off
+					"spring.ai.openai.api-key=API_KEY",
+					"spring.ai.openai.base-url=TEST_BASE_URL",
+
+					"spring.ai.openai.image.options.model=gpt-image-1",
+					"spring.ai.openai.image.options.quality=high",
+					"spring.ai.openai.image.options.size=1024x1024",
+					"spring.ai.openai.image.options.background=transparent",
+					"spring.ai.openai.image.options.moderation=low",
+					"spring.ai.openai.image.options.output_compression=85",
+					"spring.ai.openai.image.options.output_format=png",
+					"spring.ai.openai.image.options.partial_images=2",
+					"spring.ai.openai.image.options.stream=true",
+					"spring.ai.openai.image.options.user=userXYZ"
+			)
+			// @formatter:on
+			.withConfiguration(AutoConfigurations.of(OpenAiImageAutoConfiguration.class))
+			.run(context -> {
+				var imageProperties = context.getBean(OpenAiImageProperties.class);
+				var connectionProperties = context.getBean(OpenAiConnectionProperties.class);
+
+				assertThat(connectionProperties.getBaseUrl()).isEqualTo("TEST_BASE_URL");
+				assertThat(connectionProperties.getApiKey()).isEqualTo("API_KEY");
+
+				assertThat(imageProperties.getOptions().getModel()).isEqualTo("gpt-image-1");
+				assertThat(imageProperties.getOptions().getQuality()).isEqualTo("high");
+				assertThat(imageProperties.getOptions().getSize()).isEqualTo("1024x1024");
+				assertThat(imageProperties.getOptions().getBackground()).isEqualTo("transparent");
+				assertThat(imageProperties.getOptions().getModeration()).isEqualTo("low");
+				assertThat(imageProperties.getOptions().getOutputCompression()).isEqualTo(85);
+				assertThat(imageProperties.getOptions().getOutputFormat()).isEqualTo("png");
+				assertThat(imageProperties.getOptions().getPartialImages()).isEqualTo(2);
+				assertThat(imageProperties.getOptions().getStream()).isTrue();
+				assertThat(imageProperties.getOptions().getUser()).isEqualTo("userXYZ");
+			});
+	}
+
 	@Test
 	void embeddingActivation() {
 

models/spring-ai-openai/pom.xml

@@ -117,6 +117,11 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 
 </project>

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiImageModel.java

@@ -21,6 +21,7 @@
 import io.micrometer.observation.ObservationRegistry;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
 
 import org.springframework.ai.image.Image;
 import org.springframework.ai.image.ImageGeneration;
@@ -29,6 +30,7 @@
 import org.springframework.ai.image.ImagePrompt;
 import org.springframework.ai.image.ImageResponse;
 import org.springframework.ai.image.ImageResponseMetadata;
+import org.springframework.ai.image.StreamingImageModel;
 import org.springframework.ai.image.observation.DefaultImageModelObservationConvention;
 import org.springframework.ai.image.observation.ImageModelObservationContext;
 import org.springframework.ai.image.observation.ImageModelObservationConvention;
@@ -43,16 +45,26 @@
 import org.springframework.util.Assert;
 
 /**
- * OpenAiImageModel is a class that implements the ImageModel interface. It provides a
- * client for calling the OpenAI image generation API.
+ * OpenAiImageModel is a class that implements the ImageModel and StreamingImageModel
+ * interfaces. It provides a client for calling the OpenAI image generation API with both
+ * synchronous and streaming capabilities.
+ *
+ * <p>
+ * Streaming image generation is supported for GPT-Image models (gpt-image-1,
+ * gpt-image-1-mini) and allows receiving partial images as they are generated. DALL-E
+ * models do not support streaming.
+ * </p>
  *
  * @author Mark Pollack
  * @author Christian Tzolov
  * @author Hyunjoon Choi
  * @author Thomas Vitale
+ * @author Alexandros Pappas
  * @since 0.8.0
+ * @see ImageModel
+ * @see StreamingImageModel
  */
-public class OpenAiImageModel implements ImageModel {
+public class OpenAiImageModel implements ImageModel, StreamingImageModel {
 
 	private static final Logger logger = LoggerFactory.getLogger(OpenAiImageModel.class);
 
@@ -205,6 +217,51 @@ private ImagePrompt buildRequestImagePrompt(ImagePrompt imagePrompt) {
 		return new ImagePrompt(imagePrompt.getInstructions(), requestOptions);
 	}
 
+	@Override
+	public Flux<ImageResponse> stream(ImagePrompt imagePrompt) {
+		// Before moving any further, build the final request ImagePrompt,
+		// merging runtime and default options.
+		ImagePrompt requestImagePrompt = buildRequestImagePrompt(imagePrompt);
+
+		OpenAiImageApi.OpenAiImageRequest imageRequest = createRequest(requestImagePrompt);
+
+		// Validate that streaming is only used with GPT-Image models
+		String model = imageRequest.model();
+		if (model != null && !model.startsWith("gpt-image-")) {
+			return Flux.error(new IllegalArgumentException(
+					"Streaming is only supported for GPT-Image models (gpt-image-1, gpt-image-1-mini). "
+							+ "Current model: " + model));
+		}
+
+		// Ensure stream is set to true
+		if (imageRequest.stream() == null || !imageRequest.stream()) {
+			imageRequest = new OpenAiImageApi.OpenAiImageRequest(imageRequest.prompt(), imageRequest.model(),
+					imageRequest.n(), imageRequest.quality(), imageRequest.responseFormat(), imageRequest.size(),
+					imageRequest.style(), imageRequest.user(), imageRequest.background(), imageRequest.moderation(),
+					imageRequest.outputCompression(), imageRequest.outputFormat(), imageRequest.partialImages(), true);
+		}
+
+		var observationContext = ImageModelObservationContext.builder()
+			.imagePrompt(imagePrompt)
+			.provider(OpenAiApiConstants.PROVIDER_NAME)
+			.build();
+
+		OpenAiImageApi.OpenAiImageRequest finalImageRequest = imageRequest;
+
+		// Stream the image generation events
+		Flux<OpenAiImageApi.OpenAiImageStreamEvent> eventStream = this.openAiImageApi.streamImage(finalImageRequest);
+
+		// Convert streaming events to ImageResponse
+		return eventStream.map(event -> {
+			Image image = new Image(null, event.b64Json());
+			OpenAiImageGenerationMetadata metadata = new OpenAiImageGenerationMetadata(null);
+			ImageGeneration generation = new ImageGeneration(image, metadata);
+			ImageResponseMetadata responseMetadata = event.createdAt() != null
+					? new ImageResponseMetadata(event.createdAt()) : new ImageResponseMetadata(null);
+			return new ImageResponse(List.of(generation), responseMetadata);
+		});
+	}
+
 	/**
 	 * Use the provided convention for reporting observation data
 	 * @param observationConvention The provided convention