AWS Bedrock and Google VertexAINote that certain Anthropic models can also be accessed via AWS Bedrock and Google VertexAI. See the
ChatBedrock and ChatVertexAI integrations to use Anthropic models via these services.Overview
Integration details
Model features
Setup
To access Anthropic (Claude) models you’ll need to install thelangchain-anthropic integration package and acquire a Claude API key.
Installation
Credentials
Head to the Claude console to sign up and generate a Claude API key. Once you’ve done this set theANTHROPIC_API_KEY environment variable:
Instantiation
Now we can instantiate our model object and generate chat completions:Invocation
Content blocks
When using tools, extended thinking, and other features, content from a single AnthropicAIMessage can either be a single string or a list of content blocks. For example, when an Anthropic model invokes a tool, the tool invocation is part of the message content (as well as being exposed in the standardized AIMessage.tool_calls):
content_blocks will render the content in a standard format that is consistent across other model providers. Read more about content blocks.
tool_calls attribute:
Multimodal
Claude supports image and PDF inputs as content blocks, both in Anthropic’s native format (see docs for vision and PDF support) as well as LangChain’s standard format.Files API
In addition to base64 data, Claude supports interactions with files through its managed Files API. The Files API can be used to upload files to a container for use with Claude’s built-in code-execution tools. See the code execution section below, for details.Upload images
Upload images
Upload PDFs
Upload PDFs
Extended thinking
Some Claude models support an extended thinking feature, which will output the step-by-step reasoning process that led to its final answer. See compatible models in the Claude documentation. To use extended thinking, specify thethinking parameter when initializing ChatAnthropic. If needed, it can also be passed in as a parameter during invocation.
You will need to specify a token budget to use this feature. See usage example below:
Prompt caching
Anthropic supports caching of elements of your prompts, including messages, tool definitions, tool results, images and documents. This allows you to re-use large documents, instructions, few-shot documents, and other data to reduce latency and costs. To enable caching on an element of a prompt, mark its associated content block using thecache_control key. See examples below:
Messages
Tools
Incremental caching in conversational applications
Prompt caching can be used in multi-turn conversations to maintain context from earlier messages without redundant processing. We can enable incremental caching by marking the final message withcache_control. Claude will automatically use the longest previously-cached prefix for follow-up messages.
Below, we implement a simple chatbot that incorporates this feature. We follow the LangChain chatbot tutorial, but add a custom reducer that automatically marks the last content block in each user message with cache_control:
cache_control keys.
Token-efficient tool use
Anthropic supports a (beta) token-efficient tool use feature. To use it, specify the relevant beta-headers when instantiating the model.Citations
Anthropic supports a citations feature that lets Claude attach context to its answers based on source documents supplied by the user. When document orsearch_result content blocks with "citations": {"enabled": True} are included in a query, Claude may generate citations in its response.
Simple example
In this example we pass a plain text document. In the background, Claude automatically chunks the input text into sentences, which are used when generating citations.In tool results (agentic RAG)
Claude supports a search_result content block representing citable results from queries against a knowledge base or other custom source. These content blocks can be passed to claude both top-line (as in the above example) and within a tool result. This allows Claude to cite elements of its response using the result of a tool call. To pass search results in response to tool calls, define a tool that returns a list ofsearch_result content blocks in Anthropic’s native format. For example:
End to end example with LangGraph
End to end example with LangGraph
Here we demonstrate an end-to-end example in which we populate a LangChain vector store with sample documents and equip Claude with a tool that queries those documents.
The tool here takes a search query and a
category string literal, but any valid tool signature can be used.Using with text splitters
Anthropic also lets you specify your own splits using custom document types. LangChain text splitters can be used to generate meaningful splits for this purpose. See the below example, where we split the LangChainREADME.md (a markdown document) and pass it to Claude as context:
Context management
Anthropic supports a context editing feature that will automatically manage the model’s context window (e.g., by clearing tool results). See the Claude documentation for details and configuration options.Context management is supported since
langchain-anthropic>=0.3.21Built-in tools
Anthropic supports a variety of built-in tools, which can be bound to the model in the usual way. Claude will generate tool calls adhering to its internal schema for the tool.Web search
Claude can use a web search tool to run searches and ground its responses with citations.Web search tool is supported since
langchain-anthropic>=0.3.13Web fetching
Claude can use a web fetching tool to run searches and ground its responses with citations.Code execution
Claude can use a code execution tool to execute code in a sandboxed environment.Anthropic’s 2025-08-25 code execution tools are supported since
langchain-anthropic>=1.0.3.The legacy 2025-05-22 tool is supported since langchain-anthropic>=0.3.14.The code sandbox does not have internet access, thus you may only use packages that are pre-installed in the environment. See the Claude docs for more info.
Use with Files API
Use with Files API
Using the Files API, Claude can write code to access files for data analysis and other purposes. See example below:Note that Claude may generate files as part of its code execution. You can access these files using the Files API:
Memory tool
Claude supports a memory tool for client-side storage and retrieval of context across conversational threads. See docs here for details.Anthropic’s built-in memory tool is supported since
langchain-anthropic>=0.3.21Remote MCP
Claude can use a MCP connector tool for model-generated calls to remote MCP servers.Remote MCP is supported since
langchain-anthropic>=0.3.14Text editor
The text editor tool can be used to view and modify text files. See docs here for details.API reference
For detailed documentation of all features and configuration options, head to theChatAnthropic API reference.