Document objects as output.
Note that all vector stores can be cast to retrievers. Refer to the vector store integration docs 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 | ❌ | ✅ | langchain-aws |
AzureAISearchRetriever | ❌ | ✅ | langchain-community |
ElasticsearchRetriever | ✅ | ✅ | langchain-elasticsearch |
VertexAISearchRetriever | ❌ | ✅ | langchain-google-community |
External index
The below retrievers will search over an external index (e.g., constructed from Internet data or similar).| Retriever | Source | Package |
|---|---|---|
ArxivRetriever | Scholarly articles on arxiv.org | langchain-community |
TavilySearchAPIRetriever | Internet search | langchain-community |
WikipediaRetriever | Wikipedia articles | langchain-community |
All retrievers
Activeloop Deep Memory
Amazon Kendra
Arcee
Arxiv
AskNews
Azure AI Search
Bedrock (Knowledge Bases)
BM25
Box
BREEBS (Open Knowledge)
Chaindesk
ChatGPT plugin
Cognee
Cohere reranker
Cohere RAG
Contextual AI Reranker
Dappier
DocArray
Dria
ElasticSearch BM25
Elasticsearch
Egnyte
Embedchain
FlashRank reranker
Fleet AI Context
Galaxia
Google Drive
Google Vertex AI Search
Graph RAG
GreenNode
IBM watsonx.ai
JaguarDB Vector Database
Kay.ai
Kinetica Vectorstore
kNN
LinkupSearchRetriever
LLMLingua Document Compressor
LOTR (Merger Retriever)
Metal
NanoPQ (Product Quantization)
Nebius
needle
Nimble Extract
Nimble Search
Outline
Permit
Pinecone Hybrid Search
Pinecone Rerank
PubMed
Qdrant Sparse Vector
RAGatouille
RePhraseQuery
Rememberizer
SEC filing
SVM
TavilySearchAPI
TF-IDF
NeuralDB
ValyuContext
Vectorize
Vespa
Wikipedia
You.com
Zep Cloud
Zep Open Source
Zotero
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