added stateful PostgreSQL server

[ahmedmustahid]

Description

Implemented MCP tools and resources using the latest MCP SDK

Server Details

• Server: Postgre SQL
• Changes to:
  1. Implemented tools, resources with latest SDK
  2. Implemented both streamable HTTP and stdio transport
  3. Implemented Stateful sessions
  4. Made the code more modular
  5. Added docker compose scripts
  6. Improved package.json

Motivation and Context

The problem with previous code:

1. only implemented with Stdio
2. The SDK was old
3. The code was not modular: addition of new tools, resources was difficult
4. There was no docker compose file
5. Sessions were not stateful

How Has This Been Tested?

Yes. Tests have been carried out.

1. Using MCP Inspector: Can successfully access resources and call tools (from a running postgres Database)
2. Using langchain ReAct agent: The agent successfully uses the Postgre SQL server for performing necessary tasks

Breaking Changes

None

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

Additional context

First setup Environment variables (database credentials) Environment Variables Setup
For http: npx @ahmedmustahid/postgres-mcp-server
For stdio: npx @ahmedmustahid/postgres-mcp-server stdio

[olaservo]

Hi, could you update this branch to make sure that it only includes your changes? Thanks!

[ahmedmustahid]

Sorry for the trouble.
Done.

Edit: There was a merge conflict at line 278 (where I added my change). I have accepted both incoming and outgoing changes to resolve the conflict.