LangChain.js MCP AdaptersSAFE
** THIS REPO HAS MOVED TO https://github.com/langchain-ai/langchainjs/tree/main/libs/langchain-mcp-adapters ** Adapters for integrating Model Context Protocol (MCP) tools with LangChain.js applications, supporting both stdio and SSE transports.
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
[!IMPORTANT] This package has been migrated into [the LangChainJS monorepo](https://github.com/langchain-ai/langchainjs/tree/main/libs/langchain-mcp-adapters).
[](https://www.npmjs.com/package/@langchain/mcp-adapters) [](https://opensource.org/licenses/MIT)
This library provides a lightweight wrapper to allow Model Context Protocol (MCP) services to be used with LangChain.js.
This project has moved. For a current description of this project, please see the up-to-date README at the project's new location.
57ea4ffefd05OBSERVED · 2026-10-06Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.
claude mcp add mcp-adapters --env FIRECRAWL_API_KEY=${FIRECRAWL_API_KEY} -- npx -y @langchain/[email protected]{
"mcpServers": {
"mcp-adapters": {
"command": "npx",
"args": [
"-y",
"@langchain/[email protected]"
],
"env": {
"FIRECRAWL_API_KEY": "${FIRECRAWL_API_KEY}"
}
}
}
}Exposed tools (7)
6 read · 1 write · 0 destructive.
| Tool | Risk | Description |
|---|---|---|
add | write | Adds two numbers together |
divide | read | Divides two numbers |
multiply | read | Multiplies two numbers |
subtract | read | Subtracts two numbers |
tool1 | read | Tool 1 |
tool2 | read | Tool 2 |
weather | read | Get the weather for a given city |
Trust audit
SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | PASS |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | PASS |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- none-observed
- Network
- none-observed
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (4)
.eslintrc.cjs
.yarnrc.yml
@modelcontextprotocol/sdk, debug, zod, @eslint/js, @langchain/core, @langchain/langgraph, @langchain/openai, @langchain/scripts
.yarn/releases/yarn-3.5.1.cjs
Gates applied: no_behavioural_pass.
57ea4ffefd05full audit observations/trust-audit/mcp-server/langchain-ai__langchain-js-mcp-adapters.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-06 | 57ea4ffefd05 | SAFE | B | 89 | first audit |
Questions
What is the LangChain.js MCP Adapters MCP server?
** THIS REPO HAS MOVED TO https://github.com/langchain-ai/langchainjs/tree/main/libs/langchain-mcp-adapters ** Adapters for integrating Model Context Protocol (MCP) tools with LangChain.js applications, supporting both stdio and SSE transports.
What tools does LangChain.js MCP Adapters expose?
7 in total: 6 read-only, 1 that write, and 0 that can delete or overwrite. Every one is listed on this page with its risk.
Is LangChain.js MCP Adapters safe to connect to an agent?
The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B.
What credentials does LangChain.js MCP Adapters need?
It reads FIRECRAWL_API_KEY from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.
How does LangChain.js MCP Adapters run?
It speaks sse and streamable-http, so it runs as a service you connect to over the network. It is published on npm as @langchain/mcp-adapters at 0.4.5.
How current is this page?
The grade is for one exact copy of the source (57ea4ffefd05), read on 2026-10-06. The repository is watched and re-audited when it changes.