google-gemini-embeddings
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ChineseGoogle Gemini Embeddings
Google Gemini 嵌入模型
Complete production-ready guide for Google Gemini embeddings API
This skill provides comprehensive coverage of the 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.
gemini-embedding-001Google Gemini嵌入模型API的完整生产就绪指南
本技能全面介绍了用于生成文本嵌入的模型,包括SDK使用、REST API模式、批量处理、与Cloudflare Vectorize的RAG集成,以及语义搜索、文档聚类等高级用例。
gemini-embedding-001Table of Contents
目录
1. Quick Start
1. 快速开始
Installation
安装
Install the Google Generative AI SDK:
bash
npm install @google/genai@^1.37.0For TypeScript projects:
bash
npm install -D typescript@^5.0.0安装Google生成式AI SDK:
bash
npm install @google/genai@^1.37.0针对TypeScript项目:
bash
npm install -D typescript@^5.0.0Environment Setup
环境配置
Set your Gemini API key as an environment variable:
bash
export GEMINI_API_KEY="your-api-key-here"Get your API key from: https://aistudio.google.com/apikey
将你的Gemini API密钥设置为环境变量:
bash
export GEMINI_API_KEY="your-api-key-here"从以下地址获取API密钥:https://aistudio.google.com/apikey
First Embedding Example
第一个嵌入示例
typescript
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); // 768Result: A 768-dimension embedding vector representing the semantic meaning of the text.
typescript
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结果:一个768维度的嵌入向量,代表文本的语义含义。
2. gemini-embedding-001 Model
2. gemini-embedding-001 模型
Model Specifications
模型规格
Current Model: (stable, production-ready)
gemini-embedding-001- Status: Stable
- Experimental: (deprecated October 2025, do not use)
gemini-embedding-exp-03-07
当前模型:(稳定,可用于生产环境)
gemini-embedding-001- 状态:稳定
- 实验性模型:(2025年10月弃用,请勿使用)
gemini-embedding-exp-03-07
Dimensions
维度
The model supports flexible output dimensionality using Matryoshka Representation Learning:
| Dimension | Use Case | Storage | Performance |
|---|---|---|---|
| 768 | Recommended for most use cases | Low | Fast |
| 1536 | Balance between accuracy and efficiency | Medium | Medium |
| 3072 | Maximum accuracy (default) | High | Slower |
| 128-3071 | Custom (any value in range) | Variable | Variable |
Default: 3072 dimensions
Recommended: 768, 1536, or 3072 for optimal performance
该模型支持使用Matryoshka表示学习实现灵活的输出维度:
| 维度 | 适用场景 | 存储 | 性能 |
|---|---|---|---|
| 768 | 推荐用于大多数场景 | 低 | 快 |
| 1536 | 在准确性和效率间取得平衡 | 中 | 中等 |
| 3072 | 最高准确性(默认值) | 高 | 较慢 |
| 128-3071 | 自定义(范围内任意值) | 可变 | 可变 |
默认值:3072维度
推荐值:768、1536或3072以获得最佳性能
Context Window
上下文窗口
- Input Limit: 2,048 tokens per text
- Input Type: Text only (no images, audio, or video)
- 输入限制:每个文本最多2048个token
- 输入类型:仅支持文本(不支持图片、音频或视频)
Rate Limits
速率限制
| Tier | RPM | TPM | RPD | Requirements |
|---|---|---|---|---|
| Free | 100 | 30,000 | 1,000 | No billing account |
| Tier 1 | 3,000 | 1,000,000 | - | Billing account linked |
| Tier 2 | 5,000 | 5,000,000 | - | $250+ spending, 30-day wait |
| Tier 3 | 10,000 | 10,000,000 | - | $1,000+ spending, 30-day wait |
RPM = Requests Per Minute
TPM = Tokens Per Minute
RPD = Requests Per Day
| 层级 | 每分钟请求数(RPM) | 每分钟token数(TPM) | 每日请求数(RPD) | 要求 |
|---|---|---|---|---|
| 免费层 | 100 | 30,000 | 1,000 | 无需绑定账单账户 |
| 层级1 | 3,000 | 1,000,000 | - | 已绑定账单账户 |
| 层级2 | 5,000 | 5,000,000 | - | 消费满250美元,等待30天 |
| 层级3 | 10,000 | 10,000,000 | - | 消费满1000美元,等待30天 |
RPM = Requests Per Minute(每分钟请求数)
TPM = Tokens Per Minute(每分钟token数)
RPD = Requests Per Day(每日请求数)
Output Format
输出格式
typescript
{
embedding: {
values: number[] // Array of floating-point numbers
}
}typescript
{
embedding: {
values: number[] // Array of floating-point numbers
}
}3. Basic Embeddings
3. 基础嵌入生成
SDK Approach (Node.js)
SDK方式(Node.js)
Single text embedding:
typescript
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, ...]单文本嵌入:
typescript
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)
Fetch方式(Cloudflare Workers)
For Workers/edge environments without SDK support:
typescript
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' }
});
}
};适用于不支持SDK的Workers/边缘环境:
typescript
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
响应解析
typescript
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 defaulttypescript
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 defaultNormalization Requirement
归一化要求
⚠️ 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:
typescript
/**
* 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 => val / magnitude);
}
// Usage with 768 or 1536 dimensions
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: {
taskType: 'RETRIEVAL_QUERY',
outputDimensionality: 768 // NOT 3072
}
});
// ❌ WRONG - Use raw values directly
const embedding = response.embedding.values;
await vectorize.insert([{ id, values: embedding }]);
// ✅ CORRECT - Normalize first
const normalized = normalize(response.embedding.values);
await vectorize.insert([{ id, values: normalized }]);⚠️ 关键注意事项:当使用3072以外的维度时,在计算相似度之前必须对嵌入向量进行归一化。只有3072维度的嵌入向量会由API预先归一化。
重要原因:未归一化的嵌入向量具有不同的量级,会扭曲余弦相似度计算,导致搜索结果不准确。
归一化辅助函数:
typescript
/**
* 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 => val / magnitude);
}
// Usage with 768 or 1536 dimensions
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: {
taskType: 'RETRIEVAL_QUERY',
outputDimensionality: 768 // NOT 3072
}
});
// ❌ WRONG - Use raw values directly
const embedding = response.embedding.values;
await vectorize.insert([{ id, values: embedding }]);
// ✅ CORRECT - Normalize first
const normalized = normalize(response.embedding.values);
await vectorize.insert([{ id, values: normalized }]);来源:官方嵌入模型文档
4. Batch Embeddings
4. 批量嵌入生成
Multiple Texts in One Request (SDK)
单次请求处理多个文本(SDK)
Generate embeddings for multiple texts simultaneously:
typescript
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}`);
});同时为多个文本生成嵌入向量:
typescript
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)
批量REST API(fetch)
Use the endpoint:
batchEmbedContentstypescript
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[]}使用端点:
batchEmbedContentstypescript
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[]}Batch API Known Issues
批量API已知问题
⚠️ Ordering Bug (December 2025): Batch API may not preserve ordering with large batch sizes (>500 texts).
- Symptom: Entry 328 appears at position 628 (silent data corruption)
- Impact: Results cannot be reliably matched back to input texts
- Workaround: Process smaller batches (<100 texts) or add unique IDs to verify ordering
- Status: Acknowledged by Google, internal bug created (P0 priority)
- Source: GitHub Issue #1207
⚠️ Memory Limit (December 2025): Large batches (>10k embeddings) can cause crash.
ERR_STRING_TOO_LONG- Error:
Cannot create a string longer than 0x1fffffe8 characters - Cause: API response includes excessive whitespace (~536MB limit)
- Workaround: Limit to <5,000 texts per batch
- Source: GitHub Issue #1205
⚠️ Rate Limit Anomaly (January 2026): Batch API may return even when under quota.
429 RESOURCE_EXHAUSTED- Status: Under investigation by Google team
- Workaround: Implement exponential backoff and retry logic
- Source: GitHub Issue #1264
⚠️ 排序Bug(2025年12月):当批量大小超过500个文本时,批量API可能无法保持顺序。
- 症状:第328条条目出现在第628位(静默数据损坏)
- 影响:结果无法可靠地与输入文本匹配
- 解决方法:处理更小的批量(<100个文本)或添加唯一ID以验证顺序
- 状态:Google已确认,已创建内部Bug(P0优先级)
- 来源:GitHub Issue #1207
⚠️ 内存限制(2025年12月):大型批量(>10k个嵌入向量)可能导致崩溃。
ERR_STRING_TOO_LONG- 错误信息:
Cannot create a string longer than 0x1fffffe8 characters - 原因:API响应包含过多空白字符,导致响应大小超过Node.js字符串限制(约536MB)
- 解决方法:每个请求的文本数量限制在<5000个
- 来源:GitHub Issue #1205
⚠️ 速率限制异常(2026年1月):即使在配额范围内,批量API仍可能返回错误。
429 RESOURCE_EXHAUSTED- 状态:Google团队正在调查中
- 解决方法:实现指数退避和重试逻辑
- 来源:GitHub Issue #1264
Chunking for Rate Limits
针对速率限制的分块处理
When processing large datasets, chunk requests to stay within rate limits:
typescript
async function batchEmbedWithRateLimit(
texts: string[],
batchSize: number = 50, // REDUCED from 100 due to ordering bug
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, 50);处理大型数据集时,将请求分块以保持在速率限制内:
typescript
async function batchEmbedWithRateLimit(
texts: string[],
batchSize: number = 50, // REDUCED from 100 due to ordering bug
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, 50);Performance Optimization
性能优化
Tips:
- Use batch API when embedding multiple texts (single request vs multiple requests)
- Choose lower dimensions (768) for faster processing and less storage
- Implement exponential backoff for rate limit errors
- Cache embeddings to avoid redundant API calls
技巧:
- 为多个文本生成嵌入时使用批量API(单次请求 vs 多次请求)
- 选择较低维度(768)以获得更快的处理速度和更少的存储需求
- 为速率限制错误实现指数退避
- 缓存嵌入向量以避免重复API调用
5. Task Types
5. 任务类型
The parameter optimizes embeddings for specific use cases. Always specify a task type for best results.
taskTypetaskTypeAvailable Task Types (8 total)
可用任务类型(共8种)
| Task Type | Use Case | Example |
|---|---|---|
| RETRIEVAL_QUERY | User search queries | "How do I fix a flat tire?" |
| RETRIEVAL_DOCUMENT | Documents to be indexed/searched | Product descriptions, articles |
| SEMANTIC_SIMILARITY | Comparing text similarity | Duplicate detection, clustering |
| CLASSIFICATION | Categorizing texts | Spam detection, sentiment analysis |
| CLUSTERING | Grouping similar texts | Topic modeling, content organization |
| CODE_RETRIEVAL_QUERY | Code search queries | "function to sort array" |
| QUESTION_ANSWERING | Questions seeking answers | FAQ matching |
| FACT_VERIFICATION | Verifying claims with evidence | Fact-checking systems |
| 任务类型 | 适用场景 | 示例 |
|---|---|---|
| RETRIEVAL_QUERY | 用户搜索查询 | "How do I fix a flat tire?" |
| RETRIEVAL_DOCUMENT | 待索引/搜索的文档 | 产品描述、文章 |
| SEMANTIC_SIMILARITY | 文本相似度比较 | 重复内容检测、聚类 |
| CLASSIFICATION | 文本分类 | 垃圾邮件检测、情感分析 |
| CLUSTERING | 相似文本分组 | 主题建模、内容组织 |
| CODE_RETRIEVAL_QUERY | 代码搜索查询 | "function to sort array" |
| QUESTION_ANSWERING | 寻求答案的问题 | FAQ匹配 |
| FACT_VERIFICATION | 用证据验证主张 | 事实核查系统 |
When to Use Which
如何选择合适的任务类型
RAG Systems (Retrieval Augmented Generation):
typescript
// When embedding user queries
const queryEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: { taskType: 'RETRIEVAL_QUERY' } // ← Use RETRIEVAL_QUERY
});
// When embedding documents for indexing
const docEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: documentText,
config: { taskType: 'RETRIEVAL_DOCUMENT' } // ← Use RETRIEVAL_DOCUMENT
});Semantic Search:
typescript
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});Document Clustering:
typescript
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'CLUSTERING' }
});RAG系统(检索增强生成):
typescript
// When embedding user queries
const queryEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: { taskType: 'RETRIEVAL_QUERY' } // ← Use RETRIEVAL_QUERY
});
// When embedding documents for indexing
const docEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: documentText,
config: { taskType: 'RETRIEVAL_DOCUMENT' } // ← Use RETRIEVAL_DOCUMENT
});语义搜索:
typescript
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});文档聚类:
typescript
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'CLUSTERING' }
});Impact on Quality
对质量的影响
Using the correct task type significantly improves retrieval quality:
typescript
// ❌ BAD: No task type specified
const embedding1 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery
});
// ✅ GOOD: Task type specified
const embedding2 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: { taskType: 'RETRIEVAL_QUERY' }
});Result: Using the right task type can improve search relevance by 10-30%.
使用正确的任务类型显著提升检索质量:
typescript
// ❌ BAD: No task type specified
const embedding1 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery
});
// ✅ GOOD: Task type specified
const embedding2 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: { taskType: 'RETRIEVAL_QUERY' }
});结果:使用正确的任务类型可将搜索相关性提升10-30%。
6. RAG Patterns
6. RAG模式
RAG (Retrieval Augmented Generation) combines vector search with LLM generation to create AI systems that answer questions using custom knowledge bases.
RAG(检索增强生成)将向量搜索与大语言模型生成相结合,创建可使用自定义知识库回答问题的AI系统。
Document Ingestion Pipeline
文档摄入流水线
typescript
import { GoogleGenAI } from "@google/genai";
const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
// Generate embeddings for chunks
async function embedChunks(chunks: string[]): Promise<number[][]> {
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: chunks,
config: {
taskType: 'RETRIEVAL_DOCUMENT', // ← Documents for indexing
outputDimensionality: 768 // ← Match Vectorize index dimensions
}
});
return response.embeddings.map(e => e.values);
}
// Store in Cloudflare Vectorize
async function storeInVectorize(
env: Env,
chunks: string[],
embeddings: number[][]
) {
const vectors = chunks.map((chunk, i) => ({
id: `doc-${Date.now()}-${i}`,
values: embeddings[i],
metadata: { text: chunk }
}));
await env.VECTORIZE.insert(vectors);
}typescript
import { GoogleGenAI } from "@google/genai";
const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
// Generate embeddings for chunks
async function embedChunks(chunks: string[]): Promise<number[][]> {
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: chunks,
config: {
taskType: 'RETRIEVAL_DOCUMENT', // ← Documents for indexing
outputDimensionality: 768 // ← Match Vectorize index dimensions
}
});
return response.embeddings.map(e => e.values);
}
// Store in Cloudflare Vectorize
async function storeInVectorize(
env: Env,
chunks: string[],
embeddings: number[][]
) {
const vectors = chunks.map((chunk, i) => ({
id: `doc-${Date.now()}-${i}`,
values: embeddings[i],
metadata: { text: chunk }
}));
await env.VECTORIZE.insert(vectors);
}Query Flow (Retrieve + Generate)
查询流程(检索+生成)
typescript
async function ragQuery(env: Env, userQuery: string): Promise<string> {
// 1. Embed user query
const queryResponse = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: {
taskType: 'RETRIEVAL_QUERY', // ← Query, not document
outputDimensionality: 768
}
});
const queryEmbedding = queryResponse.embedding.values;
// 2. Search Vectorize for similar documents
const results = await env.VECTORIZE.query(queryEmbedding, {
topK: 5,
returnMetadata: true
});
// 3. Extract context from top results
const context = results.matches
.map(match => match.metadata.text)
.join('\n\n');
// 4. Generate response with context
const response = await ai.models.generateContent({
model: 'gemini-2.5-flash',
contents: `Context:\n${context}\n\nQuestion: ${userQuery}\n\nAnswer based on the context above:`
});
return response.text;
}typescript
async function ragQuery(env: Env, userQuery: string): Promise<string> {
// 1. Embed user query
const queryResponse = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: userQuery,
config: {
taskType: 'RETRIEVAL_QUERY', // ← Query, not document
outputDimensionality: 768
}
});
const queryEmbedding = queryResponse.embedding.values;
// 2. Search Vectorize for similar documents
const results = await env.VECTORIZE.query(queryEmbedding, {
topK: 5,
returnMetadata: true
});
// 3. Extract context from top results
const context = results.matches
.map(match => match.metadata.text)
.join('\n\n');
// 4. Generate response with context
const response = await ai.models.generateContent({
model: 'gemini-2.5-flash',
contents: `Context:\n${context}\n\nQuestion: ${userQuery}\n\nAnswer based on the context above:`
});
return response.text;
}Integration with Cloudflare Vectorize
与Cloudflare Vectorize集成
Create Vectorize Index (768 dimensions for Gemini):
bash
npx wrangler vectorize create gemini-embeddings --dimensions 768 --metric cosineBind in wrangler.jsonc:
jsonc
{
"name": "my-rag-app",
"main": "src/index.ts",
"compatibility_date": "2025-10-25",
"vectorize": {
"bindings": [
{
"binding": "VECTORIZE",
"index_name": "gemini-embeddings"
}
]
}
}Complete RAG Worker:
See for full implementation.
templates/rag-with-vectorize.ts创建Vectorize索引(针对Gemini使用768维度):
bash
npx wrangler vectorize create gemini-embeddings --dimensions 768 --metric cosine在wrangler.jsonc中绑定:
jsonc
{
"name": "my-rag-app",
"main": "src/index.ts",
"compatibility_date": "2025-10-25",
"vectorize": {
"bindings": [
{
"binding": "VECTORIZE",
"index_name": "gemini-embeddings"
}
]
}
}完整RAG Worker:
查看获取完整实现。
templates/rag-with-vectorize.ts7. Error Handling
7. 错误处理
Common Errors
常见错误
1. API Key Missing or Invalid
typescript
// ❌ Error: API key not set
const ai = new GoogleGenAI({});
// ✅ Correct
const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
if (!process.env.GEMINI_API_KEY) {
throw new Error('GEMINI_API_KEY environment variable not set');
}2. Dimension Mismatch
typescript
// ❌ Error: Embedding has 3072 dims, Vectorize expects 768
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text
// No outputDimensionality specified → defaults to 3072
});
await env.VECTORIZE.insert([{
id: '1',
values: embedding.embedding.values // 3072 dims, but index is 768!
}]);
// ✅ Correct: Match dimensions
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 } // ← Match index dimensions
});3. Rate Limiting
typescript
// ❌ Error: 429 Too Many Requests
for (let i = 0; i < 1000; i++) {
await ai.models.embedContent({ /* ... */ }); // Exceeds 100 RPM on free tier
}
// ✅ Correct: Implement rate limiting
async function embedWithRetry(text: string, maxRetries = 3) {
for (let attempt = 0; attempt < maxRetries; attempt++) {
try {
return await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
} catch (error: any) {
if (error.status === 429 && attempt < maxRetries - 1) {
const delay = Math.pow(2, attempt) * 1000; // Exponential backoff
await new Promise(resolve => setTimeout(resolve, delay));
continue;
}
throw error;
}
}
}See for all 8 documented errors with detailed solutions.
references/top-errors.md1. API密钥缺失或无效
typescript
// ❌ Error: API key not set
const ai = new GoogleGenAI({});
// ✅ Correct
const ai = new GoogleGenAI({ apiKey: process.env.GEMINI_API_KEY });
if (!process.env.GEMINI_API_KEY) {
throw new Error('GEMINI_API_KEY environment variable not set');
}2. 维度不匹配
typescript
// ❌ Error: Embedding has 3072 dims, Vectorize expects 768
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text
// No outputDimensionality specified → defaults to 3072
});
await env.VECTORIZE.insert([{
id: '1',
values: embedding.embedding.values // 3072 dims, but index is 768!
}]);
// ✅ Correct: Match dimensions
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 } // ← Match index dimensions
});3. 速率限制
typescript
// ❌ Error: 429 Too Many Requests
for (let i = 0; i < 1000; i++) {
await ai.models.embedContent({ /* ... */ }); // Exceeds 100 RPM on free tier
}
// ✅ Correct: Implement rate limiting
async function embedWithRetry(text: string, maxRetries = 3) {
for (let attempt = 0; attempt < maxRetries; attempt++) {
try {
return await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
} catch (error: any) {
if (error.status === 429 && attempt < maxRetries - 1) {
const delay = Math.pow(2, attempt) * 1000; // Exponential backoff
await new Promise(resolve => setTimeout(resolve, delay));
continue;
}
throw error;
}
}
}查看获取所有8种已记录错误的详细解决方案。
references/top-errors.mdKnown Issues Prevention
已知问题预防
This section documents additional issues discovered in production use (beyond basic errors above).
本节记录了在生产使用中发现的其他问题(超出上述基本错误)。
Issue #9: Normalization Required for Non-3072 Dimensions
问题#9:非3072维度需要归一化
Error: Incorrect similarity scores, no error thrown
Source: Official Embeddings Documentation
Why It Happens: Only 3072-dimensional embeddings are pre-normalized by the API. All other dimensions (128-3071) have varying magnitudes that distort cosine similarity.
Prevention: Always normalize embeddings when using dimensions other than 3072.
typescript
function normalize(vector: number[]): number[] {
const magnitude = Math.sqrt(vector.reduce((sum, val) => sum + val * val, 0));
return vector.map(val => val / magnitude);
}
// When using 768 or 1536 dimensions
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 }
});
const normalized = normalize(response.embedding.values);
// Now safe for similarity calculations错误表现:相似度分数不正确,无错误抛出
来源:官方嵌入模型文档
原因:只有3072维度的嵌入向量会由API预先归一化。其他所有维度(128-3071)的向量量级不同,会扭曲余弦相似度。
预防措施:当使用3072以外的维度时,始终对嵌入向量进行归一化。
typescript
function normalize(vector: number[]): number[] {
const magnitude = Math.sqrt(vector.reduce((sum, val) => sum + val * val, 0));
return vector.map(val => val / magnitude);
}
// When using 768 or 1536 dimensions
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 }
});
const normalized = normalize(response.embedding.values);
// Now safe for similarity calculationsIssue #10: Batch API Ordering Bug
问题#10:批量API排序Bug
Error: Silent data corruption - embeddings returned in wrong order
Source: GitHub Issue #1207
Why It Happens: Batch API does not preserve ordering with large batch sizes (>500 texts). Example: entry 328 appears in position 628.
Prevention: Process smaller batches (<100 texts) or add unique identifiers to verify ordering.
typescript
// Safer approach with verification
const taggedTexts = texts.map((text, i) => `[ID:${i}] ${text}`);
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: taggedTexts,
config: { taskType: 'RETRIEVAL_DOCUMENT', outputDimensionality: 768 }
});
// Verify ordering by parsing IDs if needed错误表现:静默数据损坏 - 嵌入向量返回顺序错误
来源:GitHub Issue #1207
原因:当批量大小超过500个文本时,批量API无法保持顺序。示例:第328条条目出现在第628位。
预防措施:处理更小的批量(<100个文本)或添加唯一标识符以验证顺序。
typescript
// Safer approach with verification
const taggedTexts = texts.map((text, i) => `[ID:${i}] ${text}`);
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: taggedTexts,
config: { taskType: 'RETRIEVAL_DOCUMENT', outputDimensionality: 768 }
});
// Verify ordering by parsing IDs if neededIssue #11: Batch API Memory Limit
问题#11:批量API内存限制
Error:
Source: GitHub Issue #1205
Why It Happens: Batch API response contains excessive whitespace causing response size to exceed Node.js string limit (~536MB) with large payloads (>10k embeddings).
Prevention: Limit batches to <5,000 texts per request.
Cannot create a string longer than 0x1fffffe8 characterstypescript
// Safe batch size
async function batchEmbedSafe(texts: string[]) {
const maxBatchSize = 5000;
if (texts.length > maxBatchSize) {
throw new Error(`Batch too large: ${texts.length} texts (max: ${maxBatchSize})`);
}
// Process batch...
}错误表现:
来源:GitHub Issue #1205
原因:批量API响应包含过多空白字符,当负载较大(>10k个嵌入向量)时,响应大小超过Node.js字符串限制(约536MB)。
预防措施:每个请求的文本数量限制在<5000个。
Cannot create a string longer than 0x1fffffe8 characterstypescript
// Safe batch size
async function batchEmbedSafe(texts: string[]) {
const maxBatchSize = 5000;
if (texts.length > maxBatchSize) {
throw new Error(`Batch too large: ${texts.length} texts (max: ${maxBatchSize})`);
}
// Process batch...
}Issue #12: LangChain Dimension Parameter Ignored (Community-sourced)
问题#12:LangChain维度参数被忽略(社区反馈)
Error: Dimension mismatch - getting 3072 dimensions instead of specified 768
Source: Medium Article
Verified: Multiple community reports
Why It Happens: LangChain's class silently ignores parameter when passed to constructor (Python SDK).
Prevention: Pass dimension parameter to method, not constructor. JavaScript users should verify new SDK doesn't have similar behavior.
GoogleGenerativeAIEmbeddingsoutput_dimensionalityembed_documents()@google/genaipython
undefined错误表现:维度不匹配 - 获得3072维度而非指定的768
来源:Medium文章
已验证:多个社区报告
原因:LangChain的类在构造函数中传入参数时会静默忽略该参数(Python SDK)。
预防措施:将维度参数传递给方法,而非构造函数。JavaScript用户应验证新版 SDK是否存在类似问题。
GoogleGenerativeAIEmbeddingsoutput_dimensionalityembed_documents()@google/genaipython
undefined❌ WRONG - parameter silently ignored
❌ WRONG - parameter silently ignored
embeddings = GoogleGenerativeAIEmbeddings(
model="gemini-embedding-001",
output_dimensionality=768 # IGNORED!
)
embeddings = GoogleGenerativeAIEmbeddings(
model="gemini-embedding-001",
output_dimensionality=768 # IGNORED!
)
✅ CORRECT - pass to method
✅ CORRECT - pass to method
embeddings = GoogleGenerativeAIEmbeddings(model="gemini-embedding-001")
result = embeddings.embed_documents(["text"], output_dimensionality=768)
undefinedembeddings = GoogleGenerativeAIEmbeddings(model="gemini-embedding-001")
result = embeddings.embed_documents(["text"], output_dimensionality=768)
undefinedIssue #13: Single Requests Use Batch Endpoint (Community-sourced)
问题#13:单次请求使用批量端点(社区反馈)
Error: Hitting rate limits faster than expected with single text embeddings
Source: GitHub Issue #427 (Python SDK)
Verified: Official issue in googleapis organization
Why It Happens: The function internally calls endpoint even for single texts. This causes higher rate limit consumption (batch endpoint has different limits).
Prevention: Add delays between single embedding requests and implement exponential backoff for 429 errors.
embed_content()batchEmbedContentstypescript
// Add delays to avoid rate limits
async function embedWithDelay(text: string, delayMs: number = 100) {
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
await new Promise(resolve => setTimeout(resolve, delayMs));
return response.embedding.values;
}错误表现:单文本嵌入时比预期更快达到速率限制
来源:GitHub Issue #427 (Python SDK)
已验证:googleapis组织的官方问题
原因:函数内部即使处理单文本也会调用端点。这会导致更高的速率限制消耗(批量端点有不同的限制)。
预防措施:在单次嵌入请求之间添加延迟,并为429错误实现指数退避。
embed_content()batchEmbedContentstypescript
// Add delays to avoid rate limits
async function embedWithDelay(text: string, delayMs: number = 100) {
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
await new Promise(resolve => setTimeout(resolve, delayMs));
return response.embedding.values;
}8. Best Practices
8. 最佳实践
Always Do
建议执行
✅ Specify Task Type
typescript
// Task type optimizes embeddings for your use case
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'RETRIEVAL_QUERY' } // ← Always specify
});✅ Match Dimensions with Vectorize
typescript
// Ensure embeddings match your Vectorize index dimensions
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 } // ← Match index
});✅ Implement Rate Limiting
typescript
// Use exponential backoff for 429 errors
async function embedWithBackoff(text: string) {
// Implementation from Error Handling section
}✅ Cache Embeddings
typescript
// Cache embeddings to avoid redundant API calls
const cache = new Map<string, number[]>();
async function getCachedEmbedding(text: string): Promise<number[]> {
if (cache.has(text)) {
return cache.get(text)!;
}
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
const embedding = response.embedding.values;
cache.set(text, embedding);
return embedding;
}✅ Use Batch API for Multiple Texts
typescript
// Single batch request vs multiple individual requests
const embeddings = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: texts, // Array of texts
config: { taskType: 'RETRIEVAL_DOCUMENT' }
});✅ 指定任务类型
typescript
// Task type optimizes embeddings for your use case
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'RETRIEVAL_QUERY' } // ← Always specify
});✅ 匹配Vectorize的维度
typescript
// Ensure embeddings match your Vectorize index dimensions
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { outputDimensionality: 768 } // ← Match index
});✅ 实现速率限制处理
typescript
// Use exponential backoff for 429 errors
async function embedWithBackoff(text: string) {
// Implementation from Error Handling section
}✅ 缓存嵌入向量
typescript
// Cache embeddings to avoid redundant API calls
const cache = new Map<string, number[]>();
async function getCachedEmbedding(text: string): Promise<number[]> {
if (cache.has(text)) {
return cache.get(text)!;
}
const response = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text,
config: { taskType: 'SEMANTIC_SIMILARITY' }
});
const embedding = response.embedding.values;
cache.set(text, embedding);
return embedding;
}✅ 为多个文本使用批量API
typescript
// Single batch request vs multiple individual requests
const embeddings = await ai.models.embedContent({
model: 'gemini-embedding-001',
contents: texts, // Array of texts
config: { taskType: 'RETRIEVAL_DOCUMENT' }
});Never Do
建议避免
❌ Don't Skip Task Type
typescript
// Reduces quality by 10-30%
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text
// Missing taskType!
});❌ Don't Mix Different Dimensions
typescript
// Can't compare embeddings with different dimensions
const emb1 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text1,
config: { outputDimensionality: 768 }
});
const emb2 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text2,
config: { outputDimensionality: 1536 } // Different dimensions!
});
// ❌ Can't calculate similarity between different dimensions
const similarity = cosineSimilarity(emb1.embedding.values, emb2.embedding.values);❌ Don't Use Wrong Task Type for RAG
typescript
// Reduces search quality
const queryEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: query,
config: { taskType: 'RETRIEVAL_DOCUMENT' } // Wrong! Should be RETRIEVAL_QUERY
});❌ 不要跳过任务类型
typescript
// Reduces quality by 10-30%
const embedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text
// Missing taskType!
});❌ 不要混合不同维度
typescript
// Can't compare embeddings with different dimensions
const emb1 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text1,
config: { outputDimensionality: 768 }
});
const emb2 = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: text2,
config: { outputDimensionality: 1536 } // Different dimensions!
});
// ❌ Can't calculate similarity between different dimensions
const similarity = cosineSimilarity(emb1.embedding.values, emb2.embedding.values);❌ 不要为RAG使用错误的任务类型
typescript
// Reduces search quality
const queryEmbedding = await ai.models.embedContent({
model: 'gemini-embedding-001',
content: query,
config: { taskType: 'RETRIEVAL_DOCUMENT' } // Wrong! Should be RETRIEVAL_QUERY
});Using Bundled Resources
使用捆绑资源
Templates (templates/)
模板(templates/)
- - Package configuration with verified versions
package.json - - Single text embedding with SDK
basic-embeddings.ts - - Fetch-based for Cloudflare Workers
embeddings-fetch.ts - - Batch processing with rate limiting
batch-embeddings.ts - - Complete RAG implementation with Vectorize
rag-with-vectorize.ts
- - 包含已验证版本的包配置
package.json - - 使用SDK的单文本嵌入示例
basic-embeddings.ts - - 基于Fetch的Cloudflare Workers示例
embeddings-fetch.ts - - 带速率限制的批量处理示例
batch-embeddings.ts - - 完整的Vectorize集成RAG实现
rag-with-vectorize.ts
References (references/)
参考资料(references/)
- - Compare Gemini vs OpenAI vs Workers AI embeddings
model-comparison.md - - Cloudflare Vectorize setup and patterns
vectorize-integration.md - - Complete RAG implementation strategies
rag-patterns.md - - Choosing the right dimensions (768 vs 1536 vs 3072)
dimension-guide.md - - 8 common errors and detailed solutions
top-errors.md
- - 比较Gemini、OpenAI和Workers AI嵌入模型
model-comparison.md - - Cloudflare Vectorize设置和模式
vectorize-integration.md - - 完整的RAG实现策略
rag-patterns.md - - 选择合适的维度(768 vs 1536 vs 3072)
dimension-guide.md - - 8种常见错误及详细解决方案
top-errors.md
Scripts (scripts/)
脚本(scripts/)
- - Verify @google/genai package version is current
check-versions.sh
- - 验证@google/genai包版本是否为最新
check-versions.sh
Official Documentation
官方文档
- Embeddings Guide: https://ai.google.dev/gemini-api/docs/embeddings
- Model Spec: https://ai.google.dev/gemini-api/docs/models/gemini#gemini-embedding-001
- Rate Limits: https://ai.google.dev/gemini-api/docs/rate-limits
- SDK Reference: https://www.npmjs.com/package/@google/genai
- Context7 Library ID:
/websites/ai_google_dev_gemini-api
- 嵌入模型指南:https://ai.google.dev/gemini-api/docs/embeddings
- 模型规格:https://ai.google.dev/gemini-api/docs/models/gemini#gemini-embedding-001
- 速率限制:https://ai.google.dev/gemini-api/docs/rate-limits
- SDK参考:https://www.npmjs.com/package/@google/genai
- Context7库ID:
/websites/ai_google_dev_gemini-api
Related Skills
相关技能
- google-gemini-api - Main Gemini API for text/image generation
- cloudflare-vectorize - Vector database for storing embeddings
- cloudflare-workers-ai - Workers AI embeddings (BGE models)
- google-gemini-api - 用于文本/图像生成的主Gemini API
- cloudflare-vectorize - 用于存储嵌入向量的向量数据库
- cloudflare-workers-ai - Workers AI嵌入模型(BGE模型)
Success Metrics
成功指标
Token Savings: ~60% compared to manual implementation
Errors Prevented: 13 documented errors with solutions (8 basic + 5 known issues)
Production Tested: ✅ Verified in RAG applications
Package Version: @google/genai@1.37.0
Last Updated: 2026-01-21
Changes: Added normalization requirement, batch API warnings (ordering bug, memory limits, rate limit anomaly), LangChain compatibility notes
Token节省:与手动实现相比节省约60%
预防的错误:13种已记录错误及解决方案(8种基本错误+5种已知问题)
生产环境测试:✅ 已在RAG应用中验证
包版本:@google/genai@1.37.0
最后更新:2026-01-21
变更:添加归一化要求、批量API警告(排序bug、内存限制、速率限制异常)、LangChain兼容性说明
License
许可证
MIT License - Free to use in personal and commercial projects.
Questions or Issues?
- GitHub: https://github.com/jezweb/claude-skills
- Email: jeremy@jezweb.net