LangChain: MCP vendor profile
LangChain connects its agents to MCP servers through MCPAdapter, built on FastMCP, which discovers a server's tools and adapts them into LangChain tools; the older langchain-mcp-adapters package remains on GitHub, as documented by the vendor. The langchain.mcp namespace requires langchain[mcp] 1.4.0 or later and is in beta; importing it raises a LangChainBetaWarning once per process (docs.langchain.com).
At a glance
| Listed as | LangChain (MCPAdapter, langchain-mcp-adapters) |
|---|---|
| Type | SDKs and frameworks |
| Home | docs.langchain.com |
| Price | open source |
| Read | 5 November 2026 |
What it does for this layer
LangChain's MCPAdapter is built on FastMCP, which handles transport inference, protocol negotiation, connection management and authentication (docs.langchain.com). MCPAdapter infers the transport from its target: an in-process FastMCP server, a local script over stdio, or a remote URL (docs.langchain.com). LangChain warns that a string target must be an http or https URL, because a string naming an existing .py or .js file would be launched as a subprocess (docs.langchain.com).
The earlier langchain-mcp-adapters package converts MCP tools into LangChain tools for LangGraph agents; the repository is MIT licensed with about 3.6k stars on 5 Nov 2026 (github.com). LangChain runs a public docs MCP server at https://docs.langchain.com/mcp (docs.langchain.com).
Products and plans
| Product | What it does | Price |
|---|---|---|
| MCPAdapter (langchain.mcp) | Client adapter that turns MCP server tools into LangChain tools. | open source; from 0 USD (source, as of 5 November 2026) |
Checks on its own domain
| Check | Domain | Result | Scanned | Method |
|---|---|---|---|---|
| Ora cached score | langchain.com | 74 of 100, grade B | 17 October 2026 | how it was taken |
| Cloudflare agent-readiness scan | langchain.com | 7 of 100, L0 Not Ready; 1 of 15 counted checks passed | 5 November 2026 | how it was taken |
What it does not do
- LangChain's MCPAdapter is a client-side adapter; it does not host MCP servers.