Quick Reference

// Chat Model
public class VertexAiChatModel implements ChatModel {
    public ChatResponse chat(ChatRequest chatRequest);
    public static Builder builder();
}

// Language Model
public class VertexAiLanguageModel implements LanguageModel {
    public Response<String> generate(String prompt);
    public static Builder builder();
}

// Embedding Model
public class VertexAiEmbeddingModel extends DimensionAwareEmbeddingModel {
    public Response<List<Embedding>> embedAll(List<TextSegment> segments);
    public String modelName();
    public List<Integer> calculateTokensCounts(List<TextSegment> segments);
    public static Builder builder();
}

// Image Model
public class VertexAiImageModel implements ImageModel {
    public Response<Image> generate(String prompt);
    public Response<List<Image>> generate(String prompt, int n);
    public Response<Image> edit(Image image, String prompt);
    public Response<Image> edit(Image image, Image mask, String prompt);
    public static Builder builder();
}

// Scoring Model
public class VertexAiScoringModel implements ScoringModel {
    public Response<List<Double>> scoreAll(List<TextSegment> segments, String query);
    public static Builder builder();
}

import dev.langchain4j.model.vertexai.VertexAiChatModel;
import dev.langchain4j.model.vertexai.VertexAiLanguageModel;
import dev.langchain4j.model.vertexai.VertexAiEmbeddingModel;
import dev.langchain4j.model.vertexai.VertexAiImageModel;
import dev.langchain4j.model.vertexai.VertexAiScoringModel;
import dev.langchain4j.model.vertexai.VertexAiEmbeddingModelName;

Builder endpoint(String endpoint);        // GCP API endpoint URL
Builder project(String project);          // Google Cloud Project ID
Builder location(String location);        // GCP region
Builder publisher(String publisher);      // Model publisher ("google")
Builder modelName(String modelName);      // Model name/version
Builder maxRetries(Integer maxRetries);   // Retry attempts on failure

Builder temperature(Double temperature);              // 0.0-1.0
Builder maxOutputTokens(Integer maxOutputTokens);    // Max response length
Builder topK(Integer topK);                          // Top-K sampling
Builder topP(Double topP);                           // Nucleus sampling
Builder credentials(GoogleCredentials credentials);  // Custom auth

Builder temperature(Double temperature);              // 0.0-1.0
Builder maxOutputTokens(Integer maxOutputTokens);    // Max response length
Builder topK(Integer topK);                          // Top-K sampling
Builder topP(Double topP);                           // Nucleus sampling

Builder maxSegmentsPerBatch(Integer maxSegmentsPerBatch);  // Max segments per API call (default: 250)
Builder maxTokensPerBatch(Integer maxTokensPerBatch);      // Max tokens per batch (default: 20,000)
Builder taskType(TaskType taskType);                       // Optimization for task type
Builder titleMetadataKey(String titleMetadataKey);         // Metadata key for titles (default: "title")
Builder autoTruncate(Boolean autoTruncate);                // Auto-truncate long texts (default: false)
Builder outputDimensionality(Integer outputDimensionality); // Custom dimension
Builder credentials(GoogleCredentials credentials);         // Custom auth

Builder seed(Long seed);                              // Random seed (0-4,294,967,295)
Builder language(String language);                    // Language code
Builder guidanceScale(Integer guidanceScale);         // Edit strength (0-21+)
Builder negativePrompt(String negativePrompt);        // What to avoid
Builder aspectRatio(AspectRatio aspectRatio);         // Image aspect ratio
Builder mimeType(MimeType mimeType);                  // PNG or JPEG
Builder compressionQuality(Integer compressionQuality); // JPEG quality (1-100)
Builder personGeneration(PersonGeneration personGeneration); // Person generation policy
Builder watermark(Boolean watermark);                 // Add watermark
Builder persistToCloudStorage(String gcsUri);         // Save to GCS
Builder withPersisting();                             // Enable local persistence
Builder persistTo(Path persistTo);                    // Local save path
Builder logRequests(Boolean logRequests);             // Log requests
Builder logResponses(Boolean logResponses);           // Log responses

Builder projectId(String projectId);                  // GCP project ID
Builder projectNumber(String projectNumber);          // GCP project number (12-digit)
Builder location(String location);                    // GCP region
Builder model(String model);                          // Ranking model name
Builder titleMetadataKey(String titleMetadataKey);    // Metadata key for titles (default: "title")

US Central:       https://us-central1-aiplatform.googleapis.com/v1/
Europe West:      https://europe-west1-aiplatform.googleapis.com/v1/
Asia Northeast:   https://asia-northeast1-aiplatform.googleapis.com/v1/

Embedding:        us-central1-aiplatform.googleapis.com:443

RETRIEVAL_QUERY, RETRIEVAL_DOCUMENT, SEMANTIC_SIMILARITY, CLASSIFICATION,
CLUSTERING, QUESTION_ANSWERING, FACT_VERIFICATION, CODE_RETRIEVAL_QUERY

SQUARE ("1:1"), PORTRAIT ("9:16"), LANDSCAPE ("16:9"),
THREE_FOURTHS ("3:4"), FOUR_THIRDS ("4:3")

PNG ("image/png"), JPEG ("image/jpeg")

DONT_ALLOW ("dont_allow"), ALLOW_ADULT ("allow_adult"), ALLOW_ALL ("allow_all")

PHOTOGRAPH, DIGITAL_ART, LANDSCAPE, SKETCH, WATERCOLOR, CYBERPUNK, POP_ART

public enum VertexAiEmbeddingModelName {
    MULTIMODALEMBEDDING (1408),
    TEXT_EMBEDDING_004 (768),
    TEXT_EMBEDDING_PREVIEW_0815 (768),
    TEXT_MULTILINGUAL_EMBEDDING_002 (768),
    TEXTEMBEDDING_GECKO_MULTILINGUAL_001 (768),
    TEXTEMBEDDING_GECKO_001 (768),
    TEXTEMBEDDING_GECKO_002 (768),
    TEXTEMBEDDING_GECKO_003 (768);

    public String toString();
    public Integer dimension();
    public static Integer knownDimension(String modelName);
}

public interface VertexAiChatModelBuilderFactory extends Supplier<VertexAiChatModel.Builder> {}
public interface VertexAiEmbeddingModelBuilderFactory extends Supplier<VertexAiEmbeddingModel.Builder> {}
public interface VertexAiLanguageModelBuilderFactory extends Supplier<VertexAiLanguageModel.Builder> {}
public interface VertexAiImageModelBuilderFactory extends Supplier<VertexAiImageModel.Builder> {}