---
source_url: "https://docs.langchain.com/oss/python/integrations/retrievers?utm_source=openai"
title: Retriever integrations - Docs by LangChain
mirrored_at: 2026-08-12T01:38:38.008Z
host: docs.langchain.com
cited_in_42a: true
mirror_canonical: "https://index.42a.ai/docs.langchain.com/oss/python/integrations/retrievers__q__utm_source_openai"
---

> **Original source:** https://docs.langchain.com/oss/python/integrations/retrievers?utm_source=openai

A [retriever](https://docs.langchain.com/oss/python/deepagents/retrieval#building-blocks) is an interface that returns documents given an unstructured query. It is more general than a vector store. A retriever does not need to be able to store documents, only to return (or retrieve) them. Retrievers can be created from vector stores, but are also broad enough to include other sources. Retrievers accept a string query as input and return a list of [`Document`](https://reference.langchain.com/python/langchain-core/documents/base/Document) objects as output. Note that all [vector stores](https://docs.langchain.com/oss/python/integrations/vectorstores) can be cast to retrievers. Refer to the vector store [integration docs](https://docs.langchain.com/oss/python/integrations/vectorstores) for available vector stores. This page lists custom retrievers, implemented via subclassing BaseRetriever.

## Bring-your-own documents

The below retrievers allow you to index and search a custom corpus of documents.

Retriever

Self-host

Cloud offering

Package

[`AmazonKnowledgeBasesRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/bedrock)

❌

✅

[`langchain-aws`](https://reference.langchain.com/python/langchain-aws/retrievers/bedrock/AmazonKnowledgeBasesRetriever)

[`ElasticsearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/elasticsearch_retriever)

✅

✅

[`langchain-elasticsearch`](https://reference.langchain.com/python/langchain-elasticsearch/retrievers/ElasticsearchRetriever)

[`MemstateRetriever`](https://memstate.ai/docs/integrations/langchain)

❌

✅

[`langchain-memstate`](https://pypi.org/project/langchain-memstate/)

[`MengramRetriever`](https://mengram.io/docs)

✅

✅

[`langchain-mengram`](https://pypi.org/project/langchain-mengram/)

[`NVIDIARAGRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/nvidia)

✅

❌

[`langchain-nvidia-ai-endpoints`](https://reference.langchain.com/python/langchain-nvidia-ai-endpoints/retrievers/NVIDIARAGRetriever)

[`VertexAISearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/google_vertex_ai_search)

❌

✅

[`langchain-google-community`](https://reference.langchain.com/python/langchain-google-community/vertex_ai_search/VertexAISearchRetriever)

## External index

The below retrievers will search over an external index (e.g., constructed from Internet data or similar).

Retriever

Source

Package

[`ParallelSearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/parallel)

Internet search via the [Parallel Search API](https://docs.parallel.ai/search/search-quickstart)

[`langchain-parallel`](https://reference.langchain.com/python/langchain-parallel/retrievers/ParallelSearchRetriever)

[`PerplexitySearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/perplexity_search)

Internet search via the [Perplexity Search API](https://docs.perplexity.ai/docs/search/quickstart)

[`langchain-perplexity`](https://reference.langchain.com/python/langchain-perplexity/retrievers/PerplexitySearchRetriever)

[`YouRetriever`](https://you.com/docs/integrations/langchain)

Internet search

[`langchain-youdotcom`](https://pypi.org/project/langchain-youdotcom/)

## All retrievers

Retriever

Self-host

Cloud offering

Package

Downloads

[`AmazonKnowledgeBasesRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/bedrock)

❌

✅

[`langchain-aws`](https://reference.langchain.com/python/langchain-aws/retrievers/bedrock/AmazonKnowledgeBasesRetriever)

[`Google drive`](https://docs.langchain.com/oss/python/integrations/retrievers/google_drive)

[`langchain-google-community`](https://pypi.org/project/langchain-google-community/)

[`VertexAISearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/google_vertex_ai_search)

❌

✅

[`langchain-google-community`](https://reference.langchain.com/python/langchain-google-community/vertex_ai_search/VertexAISearchRetriever)

[`Pinecone rerank`](https://docs.langchain.com/oss/python/integrations/retrievers/pinecone_rerank)

[`langchain-pinecone`](https://pypi.org/project/langchain-pinecone/)

[`Cohere RAG`](https://docs.langchain.com/oss/python/integrations/retrievers/cohere)

[`langchain-cohere`](https://pypi.org/project/langchain-cohere/)

[`Cohere reranker`](https://docs.langchain.com/oss/python/integrations/retrievers/cohere-reranker)

[`langchain-cohere`](https://pypi.org/project/langchain-cohere/)

[`NVIDIARAGRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/nvidia)

✅

❌

[`langchain-nvidia-ai-endpoints`](https://reference.langchain.com/python/langchain-nvidia-ai-endpoints/retrievers/NVIDIARAGRetriever)

[`WatsonxRerank`](https://docs.langchain.com/oss/python/integrations/retrievers/ibm_watsonx_ranker)

[`langchain-ibm`](https://reference.langchain.com/python/integrations/langchain_ibm/)

[`PerplexitySearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/perplexity_search)

❌

✅

[`langchain-perplexity`](https://reference.langchain.com/python/langchain-perplexity/retrievers/PerplexitySearchRetriever)

[`ElasticsearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/elasticsearch_retriever)

✅

✅

[`langchain-elasticsearch`](https://reference.langchain.com/python/langchain-elasticsearch/retrievers/ElasticsearchRetriever)

[`Graph RAG`](https://docs.langchain.com/oss/python/integrations/retrievers/graph_rag)

[`langchain-graph-retriever`](https://pypi.org/project/langchain-graph-retriever/)

[`Ragatouille`](https://docs.langchain.com/oss/python/integrations/retrievers/ragatouille)

[`ragatouille`](https://pypi.org/project/ragatouille/)

[`Self Querying with SAP HANA Cloud Vector Engine`](https://pypi.org/project/langchain-hana/)

[`langchain-hana`](https://pypi.org/project/langchain-hana/)

[`M3Retriever`](https://github.com/skynetcmd/m3-memory/blob/main/docs/integrations/LANGCHAIN.md)

✅

❌

[`m3-memory`](https://pypi.org/project/m3-memory/)

[`Nebius`](https://docs.tokenfactory.nebius.com/quickstart)

[`langchain-nebius`](https://pypi.org/project/langchain-nebius/)

[`ParallelSearchRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/parallel)

❌

✅

[`langchain-parallel`](https://reference.langchain.com/python/langchain-parallel/retrievers/ParallelSearchRetriever)

[`LinkupSearchRetriever`](https://github.com/LinkupPlatform/langchain-linkup)

[`langchain-linkup`](https://pypi.org/project/langchain-linkup/)

[`CKGRetriever`](https://github.com/Yarmoluk/langchain-ckg)

[`langchain-ckg`](https://pypi.org/project/langchain-ckg/)

[`Nimble Extract`](https://docs.nimbleway.com/integrations/connectors/langchain)

[`langchain-nimble`](https://pypi.org/project/langchain-nimble/)

[`Nimble Search`](https://docs.nimbleway.com/integrations/connectors/langchain)

[`langchain-nimble`](https://pypi.org/project/langchain-nimble/)

[`ReplyLayerRetriever`](https://replylayer.ai/docs/guides/langchain)

❌

✅

[`langchain-replylayer`](https://pypi.org/project/langchain-replylayer/)

[`YouRetriever`](https://you.com/docs/integrations/langchain)

❌

✅

[`langchain-youdotcom`](https://pypi.org/project/langchain-youdotcom/)

[`SingleStoreSQLDatabaseRetriever`](https://github.com/singlestore-labs/langchain-singlestore/)

[`langchain-singlestore`](https://pypi.org/project/langchain-singlestore/)

[`PerseusVaultRetriever`](https://github.com/Perseus-Computing-LLC/langchain-perseus-vault)

✅

❌

[`langchain-perseus-vault`](https://pypi.org/project/langchain-perseus-vault/)

[`SynapRetriever`](https://www.maximem.ai/)

[`maximem-synap-langchain`](https://pypi.org/project/maximem-synap-langchain/)

[`Contextual AI reranker`](https://docs.contextual.ai/)

[`langchain-contextual`](https://pypi.org/project/langchain-contextual/)

[`Valyucontext`](https://docs.valyu.ai/overview)

[`langchain-valyu`](https://pypi.org/project/langchain-valyu/)

[`Sourcey`](https://sourcey.com/docs/guides/guide-langchain-retriever)

[`langchain-sourcey`](https://pypi.org/project/langchain-sourcey/)

[`BoxRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/box)

[`langchain-box`](https://pypi.org/project/langchain-box/)

[`PolarisRetriever`](https://github.com/Veroq-ai/polaris-sdks/tree/main/python/langchain_polaris)

[`langchain-polaris`](https://pypi.org/project/langchain-polaris/)

[`Dappier`](https://docs.dappier.com/)

[`langchain-dappier`](https://pypi.org/project/langchain-dappier/)

[`MemstateRetriever`](https://memstate.ai/docs/integrations/langchain)

❌

✅

[`langchain-memstate`](https://pypi.org/project/langchain-memstate/)

[`AlchemystMemory`](https://getalchemystai.com/docs)

❌

✅

[`alchemyst-langchain`](https://pypi.org/project/alchemyst-langchain/)

[`AxioraRetriever`](https://axiora.dev/docs)

❌

✅

[`langchain-axiora`](https://pypi.org/project/langchain-axiora/)

[`Kinetica vectorstore based retriever`](https://github.com/kineticadb/langchain-kinetica)

[`langchain-kinetica`](https://pypi.org/project/langchain-kinetica/)

[`MengramRetriever`](https://mengram.io/docs)

✅

✅

[`langchain-mengram`](https://pypi.org/project/langchain-mengram/)

[`SpiceDB Retriever`](https://github.com/authzed/langchain-spicedb)

[`langchain-spicedb`](https://pypi.org/project/langchain-spicedb/)

[`HighSNRDocumentCompressor`](https://www.high-snr.com/docs.html)

❌

✅

[`langchain-highsnr`](https://pypi.org/project/langchain-highsnr/)

[`arXiv`](https://j1c.github.io/langchain-arxiv-retriever)

[`langchain-arxiv-retriever`](https://pypi.org/project/langchain-arxiv-retriever/)

[`Galaxia`](https://smabbler.gitbook.io/smabbler/api-rag/smabblers-api-rag)

[`langchain-galaxia-retriever`](https://pypi.org/project/langchain-galaxia-retriever/)

[`Permit`](https://docs.permit.io/)

[`langchain-permit`](https://pypi.org/project/langchain-permit/)

[`DeweyRetriever`](https://github.com/meetdewey/langchain-dewey)

❌

✅

[`langchain-dewey`](https://pypi.org/project/langchain-dewey/)

[`EgnyteRetriever`](https://docs.langchain.com/oss/python/integrations/retrievers/egnyte)

[`egnyte-langchain-connector`](https://pypi.org/project/egnyte-langchain-connector/)

[`DiffbotKnowledgeGraphRetriever`](https://github.com/diffbot/langchain-diffbot)

[`langchain-diffbot`](https://pypi.org/project/langchain-diffbot/)

[`DiffbotWebSearchRetriever`](https://github.com/diffbot/langchain-diffbot)

[`langchain-diffbot`](https://pypi.org/project/langchain-diffbot/)

[`Cognee`](https://docs.cognee.ai/)

[`langchain-cognee`](https://pypi.org/project/langchain-cognee/)

[`VectorizeRetriever`](https://docs.vectorize.io/rag-pipelines/retrieval-endpoint#access-tokens)

[`langchain-vectorize`](https://pypi.org/project/langchain-vectorize/)

[`AgentMail`](https://github.com/agentmail-to/langchain-agentmail)

[`langchain-agentmail`](https://pypi.org/project/langchain-agentmail/)

[`IgptSearchRetriever`](https://docs.igpt.ai/docs/api-reference/search)

[`langchain-igpt`](https://pypi.org/project/langchain-igpt/)

[`EngramRetriever`](https://engram.ai/)

[`langchain-engram`](https://pypi.org/project/langchain-engram/)

[`Zotero`](https://github.com/TimBMK/langchain-zotero-retriever)

[`langchain-zotero-retriever`](https://pypi.org/project/langchain-zotero-retriever/)

[`KeiroRetriever`](https://github.com/Keirolabs-API/langchain-keiro)

❌

✅

[`langchain-keiro`](https://pypi.org/project/langchain-keiro/)

[`Greennode`](https://greennode.ai/)

[`langchain-greennode`](https://pypi.org/project/langchain-greennode/)

[`Perigon`](https://perigon.io/docs/api/intro)

[`langchain-perigon`](https://pypi.org/project/langchain-perigon/)

[`IMAP`](https://github.com/jfouret/langchain-imap)

[`langchain-imap`](https://pypi.org/project/langchain-imap/)

[`OpenMemoryRetriever`](https://github.com/nullure/langchain-openmemory)

[`langchain-openmemory`](https://pypi.org/project/langchain-openmemory/)

* * *