A raw Postgres MCP server and the AI2SQL Gateway both do the same core job: expose
run_query and describe_schema so an agent can work with your database. They
diverge on what surrounds that. This isn't a "we win everything" comparison — each is the right
answer for different situations.
Where a raw Postgres MCP server wins
- Data never leaves your network. Self-hosted servers (Postgres MCP Pro, DBHub) run inside your infrastructure. A hosted gateway means queries and results transit a third party — a real objection if that's disqualifying for you.
- Free and open source. The OSS servers are MIT-licensed. No subscription, no vendor.
- Many database engines. DBHub speaks Postgres, MySQL, SQL Server, MariaDB and SQLite. AI2SQL Gateway is PostgreSQL-first today.
- Performance tooling. Postgres MCP Pro does index tuning and database-health analysis. The gateway doesn't — it's about safe access, not optimisation.
Where the AI2SQL Gateway wins
- Nothing to run. No process to deploy, patch or secure. Connect a database, get a key, paste one config.
- Statement-aware read-only, two layers. Every statement is classified before it runs, and queries execute in a read-only transaction. A read-only transaction alone has been bypassed in the wild (the archived official server); classifying first is defense in depth.
- Credentials never reach the agent. Connection details are encrypted server-side; the agent holds a revocable key, not your password. Raw setups typically put the DSN in a config file.
- Audit by default. Every query is logged with the key that ran it, in a dashboard. The OSS Postgres MCP servers don't ship an audit trail.
- Revocable, per-agent keys and metering. Cut off one agent without touching the others; see usage per key.
How to choose
It comes down to two questions. Does data have to stay in your network? If yes, self-host — the gateway isn't for you, and that's fine. Do you want zero ops and a built-in audit trail? If yes, the gateway is the shortest path: no server to run, read-only enforced two ways, every query logged, keys you can revoke.
A reasonable rule of thumb: raw self-hosted MCP for a local or fully-internal database where you want control and don't need audit; the AI2SQL Gateway for a database where "who queried what, and can I stop them instantly?" is a question you'll eventually be asked. For the wider field including DBHub, Supabase MCP and enterprise platforms, see Postgres MCP server options compared. To connect Claude, Cursor or ChatGPT with OAuth sign-in, see the AI2SQL MCP server setup.