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.