Langgraph-MCP Client for Postgresql Example

Name: Langgraph-MCP Client for Postgresql Example
Author: BrianCusack

@BrianCusack

代码仓库

关于 Langgraph-MCP Client for Postgresql Example

LangGraph implementation interacting with a PostgreSQL MCP Server

基本信息

分类

推理

运行时

python

传输方式

stdio

发布者

BrianCusack

配置

使用下面的配置,将此服务器添加到你的 MCP 客户端。

{
  "mcpServers": {
    "LangGraph-MCP-Client": {
      "command": "uv",
      "args": [
        "sync"
      ]
    }
  }
}

工具

未检测到工具

工具是从 README 中自动提取的。维护者可以在 ## Tools 标题下列出工具,即可填充这部分内容。

概览

What is Langgraph-MCP Client for Postgresql Example?

This repository demonstrates a low-level example of how to interact with an MCP server as a Docker image, connected to a PostgreSQL database for LangGraph agents. It is intended for developers who want to integrate PostgreSQL data sources with LangGraph using the Model Context Protocol (MCP).

How to use Langgraph-MCP Client for Postgresql Example?

Clone the repository, create a .env file with database credentials (DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, DB_NAME), install the UV package globally, and build the MCP Postgres Docker image. Then run uv sync followed by uv run queryagent to start the query agent, optionally passing a natural language query as an argument (e.g., uv run queryagent "Who holds the most funds in their account?").

Key features of Langgraph-MCP Client for Postgresql Example

Connects to a PostgreSQL database via an MCP server.
Uses langchain_mcp_adapters.tools.load_mcp_tools to create MCP tools.
Employs LangGraph's create_react_agent for fast agent templating.
Outputs the agent’s stream to a file.
Accepts user queries via command line.

Use cases of Langgraph-MCP Client for Postgresql Example

Querying a banking database using natural language questions.
Learning how to integrate a PostgreSQL MCP server with LangGraph agents.
Prototyping a LangGraph agent that uses database tools over MCP.

FAQ from Langgraph-MCP Client for Postgresql Example

What are the prerequisites for running this project?

You need Docker, a running PostgreSQL database, and the MCP Servers repository (to build the Postgres MCP image). The UV package manager must also be installed globally.

How do I set up the database connection?

Create a .env file in the repository root with the variables DB_HOST, DB_PORT, DB_USER, DB_PASSWORD, and DB_NAME, replacing placeholders with your actual credentials.