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 |
| ClickHouse | 9000 | Analytical |
| SQLite | — | Embedded |
| Cassandra / ScyllaDB | 9042 | NoSQL |
| Greenplum | 5432 | Analytical |
| Supabase | 5432 | Cloud |
| Snowflake | 443 | Cloud |
| Google BigQuery | — | Cloud |
Creating a Connection
Navigate to Connections in the sidebar and click New Connection.
| Field | Required | Description |
|---|
| Name | Yes | Display name for the connection |
| Database Type | Yes | Select from 9 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 |
Cloud databases (BigQuery, Snowflake, Supabase) have different required fields — the form adapts automatically based on the selected database type.
SSL Modes
For PostgreSQL connections:
disable — No SSLallow — Try non-SSL first, then SSLprefer — Try SSL first, then non-SSL (default)require — Require SSL, skip CA verificationverify-ca — Require SSL with CA verificationverify-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:
- Attempt to establish a connection using the provided credentials
- Execute a lightweight health-check query
- 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 |
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
