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 |