get_database_connections

Monitor active database connections in self-hosted Supabase to track usage and identify idle sessions for optimization.

Instructions

Retrieves information about active database connections from pg_stat_activity.

Input Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Implementation Reference

src/tools/get_database_connections.ts:36-64 (handler)

The execute handler function that fetches active database connections by querying pg_stat_activity, using shared utilities for SQL execution and response handling.

execute: async (input: GetDbConnectionsInput, context: ToolContext) => {
    const client = context.selfhostedClient;

    // Query pg_stat_activity
    // Note: Access to pg_stat_activity might require superuser or specific grants.
    const getConnectionsSql = `
        SELECT
            pid,
            datname,
            usename,
            application_name,
            client_addr::text, -- Cast inet to text
            backend_start::text, -- Cast timestamp to text
            state,
            query
        FROM
            pg_stat_activity
        WHERE
            backend_type = 'client backend' -- Exclude background workers, etc.
            -- Optionally filter out self?
            -- AND pid != pg_backend_pid()
        ORDER BY
            backend_start
    `;

    const result = await executeSqlWithFallback(client, getConnectionsSql, true);

    return handleSqlResponse(result, GetDbConnectionsOutputSchema);
},

src/tools/get_database_connections.ts:7-16 (schema)

Zod schema defining the structure of the output: an array of database connection objects with fields like datname, usename, state, etc.

const GetDbConnectionsOutputSchema = z.array(z.object({
    datname: z.string().nullable().describe('Database name'),
    usename: z.string().nullable().describe('User name'),
    application_name: z.string().nullable().describe('Application name (e.g., PostgREST, psql)'),
    client_addr: z.string().nullable().describe('Client IP address'),
    backend_start: z.string().nullable().describe('Time when the backend process started'),
    state: z.string().nullable().describe('Current connection state (e.g., active, idle)'),
    query: z.string().nullable().describe('Last or current query being executed'),
    pid: z.number().describe('Process ID of the backend'),
}));

src/tools/get_database_connections.ts:19-20 (schema)

Zod input schema (empty object, no parameters required).

const GetDbConnectionsInputSchema = z.object({});
type GetDbConnectionsInput = z.infer<typeof GetDbConnectionsInputSchema>;

src/index.ts:16-16 (registration)

Import of the getDatabaseConnectionsTool.

import { getDatabaseConnectionsTool } from './tools/get_database_connections.js';

src/index.ts:105-105 (registration)
Registration of the tool in the availableTools object used by the MCP server.
```
[getDatabaseConnectionsTool.name]: getDatabaseConnectionsTool as AppTool,
```

Self-Hosted Supabase MCP Server