---
title: "AzureAISearchEmbeddingRetriever"
id: azureaisearchembeddingretriever
slug: "/azureaisearchembeddingretriever"
description: "An embedding Retriever compatible with the Azure AI Search Document Store."
---

# AzureAISearchEmbeddingRetriever

An embedding Retriever compatible with the Azure AI Search Document Store.

This Retriever accepts the embeddings of a single query as input and returns a list of matching documents.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | 1. After a Text Embedder and before a [`PromptBuilder`](../builders/promptbuilder.mdx) in a RAG pipeline 2. The last component in the embedding retrieval pipeline 3. After a Text Embedder and before an [`ExtractiveReader`](../readers/extractivereader.mdx) in an extractive QA pipeline |
| **Mandatory init variables**           | `document_store`: An instance of [`AzureAISearchDocumentStore`](../../document-stores/azureaisearchdocumentstore.mdx)                                                                                                                                                                           |
| **Mandatory run variables**            | `query_embedding`: A list of floats                                                                                                                                                                                                                                       |
| **Output variables**                   | `documents`: A list of documents                                                                                                                                                                                                                                          |
| **API reference**                      | [Azure AI Search](/reference/integrations-azure_ai_search)                                                                                                                                                                                                                       |
| **GitHub link**                        | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/azure_ai_search                                                                                                                                                                         |
| **Package name** | `azure-ai-search-haystack` |

</div>

## Overview

The `AzureAISearchEmbeddingRetriever` is an embedding-based Retriever compatible with the `AzureAISearchDocumentStore`. It compares the query and document embeddings and fetches the most relevant documents from the `AzureAISearchDocumentStore` based on the outcome.

The query needs to be embedded before being passed to this component. For example, you could use a Text [Embedder](../embedders.mdx) component.

By default, the `AzureAISearchDocumentStore` uses the [HNSW algorithm](https://learn.microsoft.com/en-us/azure/search/vector-search-overview#nearest-neighbors-search) with cosine similarity to handle vector searches. The vector configuration is set during the initialization of the document store and can be customized by providing the `vector_search_configuration` parameter.

In addition to the `query_embedding`, the `AzureAISearchEmbeddingRetriever` accepts other optional parameters, including `top_k` (the maximum number of documents to retrieve) and `filters` to narrow down the search space.

:::info[Semantic Ranking]

The semantic ranking capability of Azure AI Search is not available for vector retrieval. To include semantic ranking in your retrieval process, use the [`AzureAISearchBM25Retriever`](azureaisearchbm25retriever.mdx) or [`AzureAISearchHybridRetriever`](azureaisearchhybridretriever.mdx). For more details, see [Azure AI documentation](https://learn.microsoft.com/en-us/azure/search/semantic-how-to-query-request?tabs=portal-query#set-up-the-query).
:::

## Usage

### Installation

This integration requires you to have an active Azure subscription with a deployed [Azure AI Search](https://azure.microsoft.com/en-us/products/ai-services/ai-search) service.

To start using Azure AI search with Haystack, install the package with:

```shell
pip install azure-ai-search-haystack
```

### On its own

This Retriever needs `AzureAISearchDocumentStore` and indexed documents to run.

```python
from haystack_integrations.document_stores.azure_ai_search import (
    AzureAISearchDocumentStore,
)
from haystack_integrations.components.retrievers.azure_ai_search import (
    AzureAISearchEmbeddingRetriever,
)

document_store = AzureAISearchDocumentStore()

retriever = AzureAISearchEmbeddingRetriever(document_store=document_store)

# example run query
retriever.run(query_embedding=[0.1] * 384)
```

### In a pipeline

Here is how you could use the `AzureAISearchEmbeddingRetriever` in a pipeline. In this example, you would create two pipelines: an indexing one and a querying one.

In the indexing pipeline, the documents are passed to the Document Embedder and then written into the Document Store.

Then, in the querying pipeline, we use a Text Embedder to get the vector representation of the input query that will be then passed to the `AzureAISearchEmbeddingRetriever` to get the results.

```python
from haystack import Document, Pipeline
from haystack.components.embedders import (
    SentenceTransformersDocumentEmbedder,
    SentenceTransformersTextEmbedder,
)
from haystack.components.writers import DocumentWriter

from haystack_integrations.components.retrievers.azure_ai_search import (
    AzureAISearchEmbeddingRetriever,
)
from haystack_integrations.document_stores.azure_ai_search import (
    AzureAISearchDocumentStore,
)

document_store = AzureAISearchDocumentStore(index_name="retrieval-example")

model = "sentence-transformers/all-mpnet-base-v2"

documents = [
    Document(content="There are over 7,000 languages spoken around the world today."),
    Document(
        content="""Elephants have been observed to behave in a way that indicates a
         high level of self-awareness, such as recognizing themselves in mirrors.""",
    ),
    Document(
        content="""In certain parts of the world, like the Maldives, Puerto Rico, and
          San Diego, you can witness the phenomenon of bioluminescent waves.""",
    ),
]

document_embedder = SentenceTransformersDocumentEmbedder(model=model)

# Indexing Pipeline
indexing_pipeline = Pipeline()
indexing_pipeline.add_component(instance=document_embedder, name="doc_embedder")
indexing_pipeline.add_component(
    instance=DocumentWriter(document_store=document_store),
    name="doc_writer",
)
indexing_pipeline.connect("doc_embedder", "doc_writer")

indexing_pipeline.run({"doc_embedder": {"documents": documents}})

# Query Pipeline
query_pipeline = Pipeline()
query_pipeline.add_component(
    "text_embedder",
    SentenceTransformersTextEmbedder(model=model),
)
query_pipeline.add_component(
    "retriever",
    AzureAISearchEmbeddingRetriever(document_store=document_store),
)
query_pipeline.connect("text_embedder.embedding", "retriever.query_embedding")

query = "How many languages are there?"

result = query_pipeline.run({"text_embedder": {"text": query}})

print(result["retriever"]["documents"][0])
```
