PostgreSQL
Read only SQL access with schema introspection, so an agent can answer questions about your data without guessing column names.
What it does
Connects an agent to a Postgres database: inspect schema, run queries, and in some builds analyse index health and slow queries.
Worth knowing the history here. The original reference Postgres server was archived, and several community servers now fill the gap. The one linked above adds query performance analysis on top of plain access.
Setup
claude mcp add postgres -- uvx postgres-mcp --access-mode=restricted
Set the connection string in DATABASE_URI.
What to watch out for
Use restricted or read only mode. An agent with write access to a database can lose data in ways that are not recoverable without a backup, and it only takes one misread instruction.
Connect to a development database first. If you must point at production, use a dedicated role with read only grants rather than your admin credentials.
Query results are data, not instructions. If your tables hold user submitted text, that text is now reaching your model.
Schema introspection is the underrated part. Most of the value is the agent knowing your actual table and column names instead of inventing plausible ones.
