PostgreSQL MCP

---
name: mcp-postgres
description: |
  Trigger when the user asks about database queries, PostgreSQL, schema
  inspection, or data exploration. Provides MCP server for Postgres access.
allowed-tools:
  - Bash(npx @anthropic/mcp-server-postgres *)
  - Bash(psql *)
  - Read
  - Write
---

# PostgreSQL MCP

MCP server for PostgreSQL: query execution, schema inspection, migration
management, and data exploration.

## Prerequisites

- PostgreSQL database accessible via connection string
- Node.js 18+ installed
- Connection string format: `postgresql://user:pass@host:5432/dbname`

## Setup

Add to your MCP config (`~/.claude/mcp.json` or project `.mcp.json`):

```json
{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": [
        "-y",
        "@anthropic/mcp-server-postgres",
        "postgresql://user:pass@localhost:5432/mydb"
      ]
    }
  }
}
```

## Available Tools

- **query** - Execute read-only SQL queries
- **schema** - Inspect table schemas, columns, and relationships
- **tables** - List all tables in the database
- **describe** - Get detailed info about a specific table

## Steps

1. Start by listing tables to understand the schema
2. Use `describe` to inspect table columns and relationships
3. Write and execute queries using the `query` tool
4. For data exploration, start with `SELECT * FROM table LIMIT 10`
5. Always use parameterized queries for any user-provided values

## Safety

- The MCP server runs queries as READ-ONLY by default
- To enable writes, add `--allow-writes` flag (use with caution)
- Never expose connection strings in committed files