> ## 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 + Claude Desktop

> How to set up a secure PostgreSQL MCP server for Claude Desktop using QueryBear. Add as a Custom Connector. Step-by-step with read-only role and example queries.

This guide walks through connecting **PostgreSQL** to **Claude Desktop** (Anthropic's macOS/Windows chat app) using QueryBear's managed MCP server. End result: any Claude Desktop conversation can query your Postgres database safely — perfect for non-technical teammates.

## What you'll need

* A QueryBear account ([sign up free](https://querybear.com/signup))
* A PostgreSQL database (any version 12+)
* Claude Desktop installed and signed in

## Step 1: Create a read-only PostgreSQL role

Run this as a Postgres superuser:

```sql theme={null}
CREATE ROLE querybear LOGIN PASSWORD 'choose-a-strong-one';
GRANT CONNECT ON DATABASE your_db TO querybear;
GRANT USAGE ON SCHEMA public TO querybear;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO querybear;
ALTER DEFAULT PRIVILEGES IN SCHEMA public
  GRANT SELECT ON TABLES TO querybear;
```

QueryBear's gateway is already read-only — this role is belt-and-suspenders.

## Step 2: Add the connection to QueryBear

In the [QueryBear dashboard](https://querybear.com/dashboard) → **Connections** → **New connection** → **PostgreSQL**:

* **Host** — e.g. `db.example.com` or your RDS endpoint
* **Port** — `5432`
* **Database**
* **User** — `querybear`
* **Password** — from Step 1
* **SSL mode** — `require`

Use the **Access** tab to allow-list tables and block sensitive columns. This is especially important for Claude Desktop since the data may be seen by non-technical users.

## Step 3: Add QueryBear to Claude Desktop

<Steps>
  <Step title="Open Settings → Connectors">
    Click your profile in the bottom-left → **Settings** → **Connectors**.
  </Step>

  <Step title="Add custom connector">
    Click **Add custom connector**.
  </Step>

  <Step title="Fill in the form">
    | Field | Value                           |
    | ----- | ------------------------------- |
    | Name  | `querybear`                     |
    | URL   | `https://mcp.querybear.com/mcp` |
  </Step>

  <Step title="Authorize">
    Claude Desktop opens an OAuth browser tab. Approve.
  </Step>
</Steps>

## Step 4: Verify

Start a new conversation in Claude Desktop:

> *"What QueryBear tools do you have, and what connections are available?"*

You should see `list_connections`, `get_schema`, `run_query`, and your Postgres connection.

## Try it

> *"Look up user with id 1842 — show their plan, signup date, and last 5 logins. Use the production connection."*

Claude calls `get_schema`, joins the relevant tables, queries Postgres through QueryBear, and answers.

## Postgres + Claude Desktop gotchas

* **OAuth scope is per Claude Desktop install**, so if you have Claude on multiple machines, each authorizes separately.
* **For non-technical users**, set up a **default connection** in QueryBear so Claude doesn't need `list_connections` every time.
* **Block PII columns aggressively** — anything Claude reads goes to Anthropic's API. Block `email`, `address`, `phone`, `ssn` at the QueryBear level if those are in your DB.
* **Audit log is essential** when sharing access. The QueryBear dashboard logs every query, with timestamp and originating client.

## Related

* [PostgreSQL MCP server](/databases/postgres) — Postgres-specific deep dive
* [Claude Desktop client](/clients/claude-desktop) — Claude Desktop overview
* [Security model](/features/security) — what the gateway protects against