Skip to main content
Midplane is a gateway between AI agents and your Postgres databases. Cursor queries your data through it, never holds a connection string, and every statement it sends is checked against your policy before it runs. You need a running gateway (get started).
1

Add the gateway

On the project’s Agents page, under Connect an agent, pick Cursor and click Add to Cursor. Cursor opens and asks to install midplane.
In ~/.cursor/mcp.json, with the gateway’s URL from that card:
2

Sign in

In Cursor’s settings under MCP, click Login next to midplane.
3

Choose what it may reach

Set each database to None, Read or Read + write, and Allow.
4

Try it

Ask Cursor which tables it can see. Its statement shows up in the project’s Query log.
You’re set: Cursor can answer questions from your data, and only what your policy allows runs. Masked columns stay masked, writes that need approval wait for a person, and every statement is in the audit log.
To cut it off, Revoke it under Connected agents on the Agents page. It has to sign in again within 15 minutes.

​
If it doesn’t work

  • Sign-in never finishes: Cursor takes the sign-in on port 8787, so nothing else may listen there, a gateway included.
  • The consent page says it wants access, with no databases: you aren’t a member of the gateway’s project, or the gateway isn’t registered. Ask an owner of the organization.
  • The localhost URL does not resolve: see troubleshooting.
Tested by apps/gateway/test/auth.test.ts for the gateway’s side; the client’s steps by hand.