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

# Connections

> Create and manage database connections for your MCP tools and resources

Database connections are the foundation of MCP Studio. Every SQL-backed tool and dynamic resource requires a connection to query data from.

## Supported Databases

| Database             | Default Port | Category   |
| -------------------- | ------------ | ---------- |
| PostgreSQL           | 5432         | Relational |
| MySQL / MariaDB      | 3306         | Relational |
| Microsoft SQL Server | 1433         | Relational |
| ClickHouse           | 9000         | Analytical |
| Cassandra / ScyllaDB | 9042         | NoSQL      |
| Greenplum            | 5432         | Analytical |
| Supabase             | 5432         | Cloud      |
| Snowflake            | 443          | Cloud      |
| Google BigQuery      | -            | Cloud      |
| SQLite               | -            | Embedded   |

## Creating a Connection

Navigate to **Connections** in the sidebar and click **New Connection**.

### Form Fields

| Field         | Required | Description                                           |
| ------------- | -------- | ----------------------------------------------------- |
| Name          | Yes      | Display name for the connection                       |
| Database Type | Yes      | Select from 10 supported types                        |
| Host          | Yes\*    | Hostname or IP address (\*not required for cloud DBs) |
| Port          | Yes\*    | Port number (auto-filled based on db type)            |
| Database      | Yes      | Database name to connect to                           |
| Username      | Yes      | Authentication username                               |
| Password      | Yes      | Authentication password (encrypted at rest)           |
| SSL Mode      | No       | SSL connection mode                                   |
| Pool Min      | No       | Minimum connection pool size                          |
| Pool Max      | No       | Maximum connection pool size                          |
| Extra Params  | No       | Additional parameters as JSON object                  |

<Note>
  Cloud databases (BigQuery, Snowflake, Supabase) have different required fields - the form adapts automatically based on the selected database type.
</Note>

### SSL Modes

For PostgreSQL connections:

* `disable` - No SSL
* `allow` - Try non-SSL first, then SSL
* `prefer` - Try SSL first, then non-SSL (default)
* `require` - Require SSL, skip CA verification
* `verify-ca` - Require SSL with CA verification
* `verify-full` - Require SSL with full hostname verification

## Testing Connection Health

After filling in the connection form, click the **Test Connection** button to verify connectivity before saving. The test will:

1. Attempt to establish a connection using the provided credentials
2. Execute a lightweight health-check query
3. Report success or display the error message

## Schema Explorer

Once a connection is saved and healthy, the schema explorer lets you browse the database structure:

* **Tables** - lists all tables in the connected database
* **Columns** - click a table to see its columns, data types, and nullability

This is useful when writing SQL queries for tools and resources.

## Queue Settings

Each connection has individual queue settings to control concurrent query execution:

| Setting                  | Range   | Default | Description                                    |
| ------------------------ | ------- | ------- | ---------------------------------------------- |
| `max_concurrent_queries` | 1-200   | 5       | Maximum simultaneous queries                   |
| `queue_timeout_seconds`  | 1-300   | 30      | How long a query waits in queue before timeout |
| `queue_enabled`          | boolean | true    | Enable or disable query queueing               |

See [Queue Management](/user-guide/queue-management) for details.

## Editing and Deleting

* **Edit**: Click a connection card to open it for editing. Modify any field and click **Save**.
* **Delete**: Click the delete icon. Connections bound to tools or resources cannot be deleted until those references are removed.

***

## See Also

<CardGroup cols={2}>
  <Card title="Tools" icon="wrench" href="/user-guide/tools">
    Build SQL-backed tools that query your connections
  </Card>

  <Card title="Resources" icon="file-code" href="/user-guide/resources">
    Create dynamic resources backed by your connections
  </Card>

  <Card title="Flow Editor" icon="diagram-project" href="/user-guide/flow-editor">
    Manage connections visually on the drag-and-drop canvas
  </Card>

  <Card title="Troubleshooting" icon="bug" href="/troubleshooting">
    Database connection failures and debugging tips
  </Card>
</CardGroup>