> ## Documentation Index
> Fetch the complete documentation index at: https://docs.querybear.com/llms.txt
> Use this file to discover all available pages before exploring further.

# PostgreSQL MCP Server

> Connect PostgreSQL to Claude, Cursor, ChatGPT, Codex, Windsurf, and Claude Desktop with QueryBear — a managed, secure, read-only Postgres MCP server.

QueryBear is a managed **Postgres MCP server**. Drop the QueryBear MCP endpoint into your AI client and it can query your PostgreSQL database through a hardened read-only gateway. No local install, no credentials in client config files, and no risk of the agent running a destructive query.

Works with PostgreSQL **12 and newer**, including managed Postgres on AWS RDS, Google Cloud SQL, Azure Database for PostgreSQL, Supabase, Neon, Render, Railway, Fly.io, and Heroku.

## Why a Postgres MCP server (vs. raw `psql`)

Without a gateway, hooking an AI to Postgres means one of two things:

1. **Give the agent direct DB credentials** — convenient and catastrophic. The agent can `DROP TABLE`, read every column of every table, and accidentally run scans that DoS your replica.
2. **Use a read-only role** — solves writes but nothing else. The agent still sees every table, every column (including `password_hash`, `email`, `api_key`), and can still run unbounded scans.

QueryBear gives you:

* A SQL parser that rejects writes at the gateway layer, including writes hidden inside CTEs.
* Per-table allow-listing — new tables stay invisible until you opt them in.
* Per-column block lists — sensitive columns are stripped from the schema the agent sees.
* Row limits and query timeouts.
* Full audit log.

See the [security model](/features/security) for the full threat list.

## Create a read-only Postgres role

QueryBear's gateway is read-only by design, but a least-privilege DB role is belt-and-suspenders. Run this as a Postgres superuser:

```sql theme={null}
-- Create the role
CREATE ROLE querybear LOGIN PASSWORD 'choose-a-strong-one';

-- Allow connecting to the database
GRANT CONNECT ON DATABASE your_db TO querybear;

-- Grant schema usage
GRANT USAGE ON SCHEMA public TO querybear;

-- Read access to existing tables
GRANT SELECT ON ALL TABLES IN SCHEMA public TO querybear;

-- Read access to future tables (so you don't have to re-grant after migrations)
ALTER DEFAULT PRIVILEGES IN SCHEMA public
  GRANT SELECT ON TABLES TO querybear;

-- Read access to existing and future sequences (some ORMs query these)
GRANT SELECT ON ALL SEQUENCES IN SCHEMA public TO querybear;
ALTER DEFAULT PRIVILEGES IN SCHEMA public
  GRANT SELECT ON SEQUENCES TO querybear;
```

If you use schemas other than `public`, repeat the `GRANT USAGE` and `ALTER DEFAULT PRIVILEGES` for each.

## Connection settings

In the QueryBear dashboard, add a new PostgreSQL connection:

* **Host** — e.g. `db.example.com`, your RDS endpoint, or Supabase pooler URL
* **Port** — `5432` by default
* **Database**
* **User** — `querybear` (the role above)
* **Password**
* **SSL mode** — `require` for any non-localhost connection

For managed Postgres providers, QueryBear knows the right SSL settings — just paste the connection string.

## Postgres-specific notes

* **CTEs with writes are rejected.** `WITH x AS (DELETE FROM ...) SELECT * FROM x` is a real Postgres feature. The QueryBear parser catches it.
* **`pg_*` system tables are visible by default for schema introspection** but are not query-allow-listed unless you opt in.
* **Read replicas work.** Point QueryBear at your replica — the gateway doesn't care.
* **Materialized views and views are first-class.** They appear in `get_schema` and are queryable like tables.
* **PgVector and other extensions work transparently** — the parser permits `<->`, `<=>`, and other operator syntax.

## Connect Postgres to your AI client

Pick your client for a step-by-step guide:

<CardGroup>
  <Card title="Claude Code" href="/guides/postgres-claude-code">
    One-line CLI setup. Read your DB from `claude` in the terminal.
  </Card>

  <Card title="Claude Desktop" href="/guides/postgres-claude-desktop">
    Custom connector in Claude's desktop app.
  </Card>

  <Card title="Cursor" href="/guides/postgres-cursor">
    Drop into `.cursor/mcp.json`. Query your DB while pairing with Cursor.
  </Card>

  <Card title="Codex" href="/guides/postgres-codex">
    Add to `~/.codex/config.toml`. Database access in Codex CLI.
  </Card>

  <Card title="Windsurf" href="/guides/postgres-windsurf">
    Add as a custom MCP server in Windsurf settings.
  </Card>

  <Card title="ChatGPT" href="/guides/postgres-chatgpt">
    Custom connector in ChatGPT (developer mode).
  </Card>
</CardGroup>