mcp-postgreSql

This MCP server provides a safe, queryable interface to a PostgreSQL database. It exposes tools for listing and inspecting schemas, performing read-only queries, and executing modification statements under separate safety boundaries. Clients can connect using the standard MCP protocol and leverage tools such as list_tables, describe_table, list_indexes, list_constraints, and search_in_table to explore data structures, while run_read_only_query and run_modification_query let you run safe read-only or DML/DDL commands as appropriate. You can also run explain_query to obtain JSON execution plans for tuning queries. The server uses a single DATABASE_URL connection string and can be accessed by MCP-enabled assistants or editor extensions to safely operate on your PostgreSQL data.

Prerequisites:

• Node.js v18 or higher
• A running PostgreSQL database

Installation steps:

1. Clone the repository:

git clone <your-repo-url>
cd mcp-postgre-server

2. Install dependencies:

npm install

3. Configure environment:

• Create a .env file (optional if you provide DATABASE_URL via the MCP config):

cp .env.example .env

• Edit your DATABASE_URL in .env or provide the value via the mcp_config.json env section (recommended for absolute paths):

# Example
DATABASE_URL=postgresql://myuser:mypassword@localhost:5432/mydatabase

4. Build the TypeScript code (if applicable):

npm run build

5. Run the server locally:

npm start

6. Optional: integrate with MCP clients by adding the appropriate mcp_config.json entry pointing to this server (see the JSON in the repository README for a sample configuration).

Tips:

• Keep DATABASE_URL secure; do not commit it to version control. Use environment variables or the MCP config env block.
• The server separates read-only and modification operations. Use run_read_only_query for SELECT-like statements and run_modification_query for INSERT/UPDATE/DELETE/CREATE, as appropriate.
• Validate table names in tools that accept freeform input to prevent SQL injection. Use provided inspection tools to minimize untrusted input.
• If you deploy behind a reverse proxy or inside a container, ensure the container has network access to the PostgreSQL instance and that SSL/TLS requirements are respected if needed.
• When debugging, start the server in a development environment and inspect logs for connection issues or query errors.