Google Gemini Embeddings

Complete production-ready guide for Google Gemini embeddings API

This skill provides comprehensive coverage of the gemini-embedding-001 model for generating text embeddings, including SDK usage, REST API patterns, batch processing, RAG integration with Cloudflare Vectorize, and advanced use cases like semantic search and document clustering.

Table of Contents

1. Quick Start
2. gemini-embedding-001 Model
3. Basic Embeddings
4. Batch Embeddings
5. Task Types
6. RAG Patterns
7. Error Handling
8. Best Practices

1. Quick Start

Installation

Install the Google Generative AI SDK:

npm install @google/genai@^1.37.0

For TypeScript projects:

npm install -D typescript@^5.0.0

Environment Setup

Set your Gemini API key as an environment variable:

export GEMINI_API_KEY="your-api-key-here"

Get your API key from: https://aistudio.google.com/apikey

First Embedding Example

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });

const response = await ai.models.embedContent({
  model: 'gemini-embedding-001',
  content: 'What is the meaning of life?',
  config: {
    taskType: 'RETRIEVAL_QUERY',
    outputDimensionality: 768
  }
});

console.log(response.embedding.values); // [0.012, -0.034, ...]
console.log(response.embedding.values.length); // 768

Result: A 768-dimension embedding vector representing the semantic meaning of the text.

2. gemini-embedding-001 Model

Model Specifications

Current Model: gemini-embedding-001 (stable, production-ready)

• Status: Stable
• Experimental: gemini-embedding-exp-03-07 (deprecated October 2025, do not use)

Dimensions

The model supports flexible output dimensionality using Matryoshka Representation Learning:

Default: 3072 dimensions Recommended: 768, 1536, or 3072 for optimal performance

Context Window

• Input Limit: 2,048 tokens per text
• Input Type: Text only (no images, audio, or video)

Rate Limits

RPM = Requests Per Minute TPM = Tokens Per Minute RPD = Requests Per Day

Output Format

{
  embedding: {
    values: number[] // Array of floating-point numbers
  }
}

3. Basic Embeddings

SDK Approach (Node.js)

Single text embedding:

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });

const response = await ai.models.embedContent({
  model: 'gemini-embedding-001',
  content: 'The quick brown fox jumps over the lazy dog',
  config: {
    taskType: 'SEMANTIC_SIMILARITY',
    outputDimensionality: 768
  }
});

console.log(response.embedding.values);
// [0.00388, -0.00762, 0.01543, ...]

Fetch Approach (Cloudflare Workers)

For Workers/edge environments without SDK support:

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const apiKey = env.GEMINI_API_KEY;
    const text = "What is the meaning of life?";

    const response = await fetch(
      'https://generativelanguage.googleapis.com/v1beta/models/gemini-embedding-001:embedContent',
      {
        method: 'POST',
        headers: {
          'x-goog-api-key': apiKey,
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          content: {
            parts: [{ text }]
          },
          taskType: 'RETRIEVAL_QUERY',
          outputDimensionality: 768
        })
      }
    );

    const data = await response.json();

    // Response format:
    // {
    //   embedding: {
    //     values: [0.012, -0.034, ...]
    //   }
    // }

    return new Response(JSON.stringify(data), {
      headers: { 'Content-Type': 'application/json' }
    });
  }
};

Response Parsing

interface EmbeddingResponse {
  embedding: {
    values: number[];
  };
}

const response: EmbeddingResponse = await ai.models.embedContent({
  model: 'gemini-embedding-001',
  content: 'Sample text',
  config: { taskType: 'SEMANTIC_SIMILARITY' }
});

const embedding: number[] = response.embedding.values;
const dimensions: number = embedding.length; // 3072 by default

Normalization Requirement

⚠️ CRITICAL: When using dimensions other than 3072, you MUST normalize embeddings before computing similarity. Only 3072-dimensional embeddings are pre-normalized by the API.

Why This Matters: Non-normalized embeddings have varying magnitudes that distort cosine similarity calculations, leading to incorrect search results.

Normalization Helper Function:

/**
 * Normalize embedding vector for accurate similarity calculations.
 * REQUIRED for dimensions other than 3072.
 *
 * @param vector - Embedding values from API response
 * @returns Normalized vector (unit length)
 */
function normalize(vector: number[]): number[] {
  const magnitude = Math.sqrt(
    vector.reduce((sum, val) => sum + val * val, 0)
  );
  return vector.map(val =>