---

name: postgres description: "Exécute des requêtes SQL en lecture seule sur plusieurs bases de données PostgreSQL. À utiliser pour : (1) interroger des bases PostgreSQL, (2) explorer les schémas/tables, (3) exécuter des requêtes SELECT pour l'analyse de données, (4) vérifier le contenu des bases. Supporte plusieurs connexions avec descriptions pour une sélection automatique intelligente. Bloque toutes les opérations d'écriture (INSERT, UPDATE, DELETE, DROP, etc.) par sécurité." version: 1.0.1 license: MIT

PostgreSQL Read-Only Query Skill

Execute safe, read-only queries against configured PostgreSQL databases.

Prerequisites

• Python 3.8+
• psycopg2-binary: pip install -r requirements.txt

Setup

Create connections.json in the skill directory or ~/.config/claude/postgres-connections.json.

Security: Set file permissions to 600 since it contains credentials:

chmod 600 connections.json

{
  "databases": [
    {
      "name": "production",
      "description": "Main app database - users, orders, transactions",
      "host": "db.example.com",
      "port": 5432,
      "database": "app_prod",
      "user": "readonly_user",
      "password": "your-password",
      "sslmode": "require"
    }
  ]
}

Config Fields

Field	Required	Description
name	Yes	Identifier for the database (case-insensitive)
description	Yes	What data this database contains (used for auto-selection)
host	Yes	Database hostname
port	No	Port number (default: 5432)
database	Yes	Database name
user	Yes	Username
password	Yes	Password
sslmode	No	SSL mode: disable, allow, prefer (default), require, verify-ca, verify-full

Usage

List configured databases

python3 scripts/query.py --list

Query a database

python3 scripts/query.py --db production --query "SELECT * FROM users LIMIT 10"

List tables

python3 scripts/query.py --db production --tables

Show schema

python3 scripts/query.py --db production --schema

Limit results

python3 scripts/query.py --db production --query "SELECT * FROM orders" --limit 100

Database Selection

Match user intent to database description:

User asks about	Look for description containing
users, accounts	users, accounts, customers
orders, sales	orders, transactions, sales
analytics, metrics	analytics, metrics, reports
logs, events	logs, events, audit

If unclear, run --list and ask user which database.

Safety Features

• Read-only session: Connection uses PostgreSQL readonly=True mode (primary protection)
• Query validation: Only SELECT, SHOW, EXPLAIN, WITH queries allowed
• Single statement: Multiple statements per query rejected
• SSL support: Configurable SSL mode for encrypted connections
• Query timeout: 30-second statement timeout enforced
• Memory protection: Max 10,000 rows per query to prevent OOM
• Column width cap: 100 char max per column for readable output
• Credential sanitization: Error messages don't leak passwords

Troubleshooting

Error	Solution
Config not found	Create connections.json in skill directory
Authentication failed	Check username/password in config
Connection timeout	Verify host/port, check firewall/VPN
SSL error	Try "sslmode": "disable" for local databases
Permission warning	Run chmod 600 connections.json

Exit Codes

• 0: Success
• 1: Error (config missing, auth failed, invalid query, database error)

Workflow

1. Run --list to show available databases
2. Match user intent to database description
3. Run --tables or --schema to explore structure
4. Execute query with appropriate LIMIT