> ## Documentation Index
> Fetch the complete documentation index at: https://ikun.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# SentenceTransformers 嵌入器

`SentenceTransformerEmbedder` 类用于使用 [SentenceTransformers](https://www.sbert.net/) 库将文本数据嵌入到向量中。

## 用法

```python cookbook/embedders/sentence_transformer_embedder.py theme={null}
from agno.agent import AgentKnowledge
from agno.vectordb.pgvector import PgVector
from agno.embedder.sentence_transformer import SentenceTransformerEmbedder

# 将句子嵌入数据库
embeddings = SentenceTransformerEmbedder().get_embedding("The quick brown fox jumps over the lazy dog.")

# 打印嵌入向量及其维度
print(f"Embeddings: {embeddings[:5]}")
print(f"Dimensions: {len(embeddings)}")

# 在知识库中使用嵌入器
knowledge_base = AgentKnowledge(
    vector_db=PgVector(
        db_url="postgresql+psycopg://ai:ai@localhost:5532/ai",
        table_name="sentence_transformer_embeddings",
        embedder=SentenceTransformerEmbedder(),
    ),
    num_documents=2,
)
```

## 参数

| 参数                            | 类型                 | 默认值                 | 描述                                |
| ----------------------------- | ------------------ | ------------------- | --------------------------------- |
| `dimensions`                  | `int`              | -                   | 生成的嵌入向量的维度                        |
| `model`                       | `str`              | `all-mpnet-base-v2` | 要使用的 SentenceTransformers 模型名称    |
| `sentence_transformer_client` | `Optional[Client]` | -                   | 可选的预配置 SentenceTransformers 客户端实例 |

## 开发人员资源

* 查看 [Cookbook](https://github.com/agno-agi/agno/blob/main/cookbook/agent_concepts/knowledge/embedders/sentence_transformer_embedder.py)