LangChain.js MCP Adapters

LangChain.js MCP Adapters is a lightweight library that enables Anthropic Model Context Protocol (MCP) tools to be compatible with LangChain.js and LangGraph.js. Its main features are:

• Connect to MCP servers: Supports connecting to MCP servers via stdio (local) or SSE (server-sent events, remote). Custom headers can also be set in SSE connections (e.g., for authentication).
• Multi-server management: Can connect to multiple MCP servers simultaneously and automatically organize the tools they provide. They can be accessed grouped by server name or as a flat collection.
• Integration with LangChain/LangGraph: Seamlessly integrates with LangChain.js and LangGraph.js, supporting OpenAI, Anthropic, and Google models.
• Flexible configuration: Provides flexible configuration options, including JSON configuration files and environment variable substitution.
• Error handling: Offers robust error handling mechanisms.

Use Cases

LangChain.js MCP Adapters are primarily used in the following scenarios:

1. Integrating external tools into LangChain/LangGraph workflows: If your application needs to use some independent tools that follow the MCP protocol, this library can integrate these tools into the LangChain/LangGraph workflow.
2. Building intelligent agents based on multiple tools: By connecting to multiple MCP servers providing different types of tools, powerful intelligent agents can be built. For example, an agent can use both math calculation tools and weather query tools at the same time.
3. Deploying and managing tools in different environments: MCP Adapters support stdio and SSE connections, allowing tools to be deployed locally or on remote servers and easily managed through simple configurations.
4. Tools requiring authentication to access: For MCP servers that require authentication, custom headers can be set in SSE connections, such as Authorization and X-API-Key.

In summary, LangChain.js MCP Adapters simplifies the process of integrating MCP tools into LangChain.js and LangGraph.js applications, making it easier to leverage external tools to enhance the intelligence and functionality of the application.