Class GeminiEmbedder

src/services/code-index/embedders/gemini.ts:18–113

 * migrated to gemini-embedding-001 for backward compatibility.
 */
export class GeminiEmbedder implements IEmbedder {
	private readonly openAICompatibleEmbedder: OpenAICompatibleEmbedder
	private static readonly GEMINI_BASE_URL = "https://generativelanguage.googleapis.com/v1beta/openai/"
	private static readonly DEFAULT_MODEL = "gemini-embedding-001"
	/**
	 * Deprecated models that are automatically migrated to their replacements.
	 * Users with these models configured will be silently migrated without interruption.
	 */
	private static readonly DEPRECATED_MODEL_MIGRATIONS: Record<string, string> = {
		"text-embedding-004": "gemini-embedding-001",
	}
	private readonly modelId: string

	/**
	 * Migrates deprecated model IDs to their replacements.
	 * @param modelId The model ID to potentially migrate
	 * @returns The migrated model ID, or the original if no migration is needed
	 */
	private static migrateModelId(modelId: string): string {
		return GeminiEmbedder.DEPRECATED_MODEL_MIGRATIONS[modelId] ?? modelId
	}

	/**
	 * Creates a new Gemini embedder
	 * @param apiKey The Gemini API key for authentication
	 * @param modelId The model ID to use (defaults to gemini-embedding-001)
	 */
	constructor(apiKey: string, modelId?: string) {
		if (!apiKey) {
			throw new Error(t("embeddings:validation.apiKeyRequired"))
		}

		// Migrate deprecated models to their replacements silently
		const migratedModelId = modelId ? GeminiEmbedder.migrateModelId(modelId) : undefined

		// Use provided model (after migration) or default
		this.modelId = migratedModelId || GeminiEmbedder.DEFAULT_MODEL

		// Create an OpenAI Compatible embedder with Gemini's configuration
		this.openAICompatibleEmbedder = new OpenAICompatibleEmbedder(
			GeminiEmbedder.GEMINI_BASE_URL,
			apiKey,
			this.modelId,
			GEMINI_MAX_ITEM_TOKENS,
		)
	}

	/**
	 * Creates embeddings for the given texts using Gemini's embedding API
	 * @param texts Array of text strings to embed
	 * @param model Optional model identifier (uses constructor model if not provided)
	 * @returns Promise resolving to embedding response
	 */
	async createEmbeddings(texts: string[], model?: string): Promise<EmbeddingResponse> {
		try {
			// Use the provided model or fall back to the instance's model
			const modelToUse = model || this.modelId
			return await this.openAICompatibleEmbedder.createEmbeddings(texts, modelToUse)