langgraph

langgraph is an agent for coding agents from jrmatherly/mcp-context-forge. It costs 0 tokens per session (459 once invoked), scanned A, a copy of langgraph, Apache-2.0.

An integration guide for using LangGraph with the MCP Gateway. LangGraph is a framework for building language-model applications as connected steps and workflows, and MCP is a standard for sharing tools with them.

In plain words
What is it for?
Use it to add real-time tool discovery, multi-server tool access, and MCP-based external services to LangGraph agents.
Why use it?
It lets a LangGraph agent discover tools from multiple MCP servers through one consistent connection.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/jrmatherly/mcp-context-forge/langgraph
Clone the repo
git clone --depth 1 https://github.com/jrmatherly/mcp-context-forge

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for langgraph

README.md
[![agentmods](https://agentmods.dev/badge/agents/jrmatherly/mcp-context-forge/langgraph.svg)](https://agentmods.dev/agents/jrmatherly/mcp-context-forge/langgraph)
Your own site
<a href="https://agentmods.dev/agents/jrmatherly/mcp-context-forge/langgraph"><img src="https://agentmods.dev/badge/agents/jrmatherly/mcp-context-forge/langgraph.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 459 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 86% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00000 $0.00459
Opus 5 $0.00000 $0.00230
Sonnet 5 $0.00000 $0.00092
Haiku 4.5 $0.00000 $0.00046

Measured yesterday against content hash 91a1c47744e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

langgraph scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to langgraph — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

docs/docs/using/agents/langgraph.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

LangGraph Integration with MCP Gateway

LangGraph is a framework for developing applications powered by language models. Integrating LangGraph with the Model Context Protocol (MCP) allows agents to utilize tools defined across one or more MCP servers, enabling seamless interaction with external data sources and services.


🧰 Key Features

  • Dynamic Tool Access: Connects to MCP servers to fetch available tools in real time.
  • Multi-Server Support: Interact with tools defined on multiple MCP servers simultaneously.
  • Standardized Communication: Utilizes the open MCP standard for consistent tool integration.

🛠 Installation

To use MCP tools in LangGraph, install the langchain-mcp-adapters package:

pip install langchain-mcp-adapters

🔗 Connecting to MCP Gateway

Here's how to set up a connection to your MCP Gateway:

from langchain_mcp_adapters.client import MultiServerMCPClient
from langgraph.prebuilt import create_react_agent

client = MultiServerMCPClient(
    {
        "gateway": {
            "url": "http://localhost:4444/mcp",
            "transport": "streamable_http",
        }
    }
)

Replace "http://localhost:4444/mcp" with the URL of your MCP Gateway.


🤖 Creating an Agent

After setting up the client, you can create a LangGraph agent:

agent = create_react_agent(
    tools=client.get_tools(),
    llm=your_language_model,
)

Replace your_language_model with your configured language model instance.


🧪 Using the Agent

Once the agent is created, you can use it to perform tasks:

response = agent.run("Use the 'weather' tool to get the forecast for Dublin.")
print(response)

📚 Additional Resources

Read the full file on GitHub · 80 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 80 lines · 0 tokens per session scan A 91a1c47744e6

Subscribe to this mod's changes

langgraph is an agent published in the GitHub repository jrmatherly/mcp-context-forge (0 stars, last pushed 6mo ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 459 tokens. A static security scan graded it A with 0 findings. It is 86% identical to langgraph, differing in 8 lines, and is treated as a copy.