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. Semantic Search
8. Document Clustering
9. Error Handling
10. Best Practices

1. Quick Start

Installation

Install the Google Generative AI SDK:

npm install @google/genai@^1.27.0

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

4. Batch Embeddings

Multiple Texts in One Request (SDK)

Generate embeddings for multiple texts simultaneously:

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

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

const texts = [
  "What is the meaning of life?",
  "How does photosynthesis work?",
  "Tell me about the history of the internet."
];

const response = await ai.models.embedContent({
  model: 'gemini-embedding-001',
  contents: texts, // Array of strings
  config: {
    taskType: 'RETRIEVAL_DOCUMENT',
    outputDimensionality: 768
  }
});

// Process each embedding
response.embeddings.forEach((embedding, index) => {
  console.log(`Text ${index}: ${texts[index]}`);
  console.log(`Embedding: ${embedding.values.slice(0, 5)}...`);
  console.log(`Dimensions: ${embedding.values.length}`);
});

Batch REST API (fetch)

Use the batchEmbedContents endpoint:

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

const data = await response.json();
// data.embeddings: Array of {values: number[]}

Chunking for Rate Limits

When processing large datasets, chunk requests to stay within rate limits:

async function batchEmbedWithRateLimit(
  texts: string[],
  batchSize: number = 100, // Free tier: 100 RPM
  delayMs: number = 60000 // 1 minute delay between batches
): Promise<number[][]> {
  const allEmbeddings: number[][] = [];

  for (let i = 0; i < texts.length; i += batchSize) {
    const batch = texts.slice(i, i + batchSize);

    console.log(`Processing batch ${i / batchSize + 1} (${batch.length} texts)`);

    const response = await ai.models.embedContent({
      model: 'gemini-embedding-001',
      contents: batch,
      config: {
        taskType: 'RETRIEVAL_DOCUMENT',
        outputDimensionality: 768
      }
    });

    allEmbeddings.push(...response.embeddings.map(e => e.values));

    // Wait before next batch (except last batch)
    if (i + batchSize < texts.length) {
      await new Promise(resolve => setTimeout(resolve, delayMs));
    }
  }

  return allEmbeddings;
}

// Usage
const embeddings = await batchEmbedWithRateLimit(documents, 100);

Performance Optimization

Tips:

1. Use batch API when embedding multiple texts (single request vs multiple requests)
2. Choose lowe