DB Readonly

---

name: db-readonly description: Run safe read-only queries against MySQL or PostgreSQL for data inspection, reporting, and troubleshooting. Use when the user asks to read tables, inspect schema, count rows, sample data, or export query results without modifying data.

---

db-readonly

Use this skill for database read tasks only.

What this skill does

Connect to PostgreSQL or MySQL using connection env vars

Execute SELECT / WITH / EXPLAIN queries only

Optionally save output to CSV/TSV/JSON

Block risky SQL (INSERT, UPDATE, DELETE, DROP, ALTER, etc.)

Connection env vars

PostgreSQL

PGHOST

PGPORT (optional, default 5432)

PGDATABASE

PGUSER

PGPASSWORD

MySQL

MYSQL_HOST

MYSQL_PORT (optional, default 3306)

MYSQL_DATABASE

MYSQL_USER

MYSQL_PASSWORD

Run

Use script:

scripts/db_readonly.sh postgres "SELECT now();"

scripts/db_readonly.sh mysql "SELECT NOW();"

Export example:

scripts/db_readonly.sh postgres "SELECT * FROM users LIMIT 100" --format csv --out /tmp/users.csv

Safety rules

1. Refuse non-read SQL. 2. Prefer LIMIT for exploratory queries. 3. When user asks for updates/deletes/schema changes, ask explicit confirmation and do not run via this skill. 4. Avoid printing secrets from env vars.

Reference

Query cookbook: references/query-cookbook.md