get_database_connections
Retrieve details of active database connections from pg_stat_activity to monitor and manage database performance and usage in a self-hosted Supabase environment.
Instructions
Retrieves information about active database connections from pg_stat_activity.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Implementation Reference
- The main handler function for the get_database_connections tool. It executes a SQL query on pg_stat_activity to retrieve details of active client backend database connections, casts certain fields to text, filters backend_type, orders by backend_start, and processes the result using shared utilities.
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); }, - Zod schemas for input (empty object), output (array of connection objects with fields like datname, usename, etc.), and static MCP input JSON schema (empty object).
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'), })); // Input schema (allow filtering by user or database later if needed) const GetDbConnectionsInputSchema = z.object({}); type GetDbConnectionsInput = z.infer<typeof GetDbConnectionsInputSchema>; // Static JSON Schema for MCP capabilities const mcpInputSchema = { type: 'object', properties: {}, required: [], }; - src/index.ts:16-16 (registration)Import statement that brings in the getDatabaseConnectionsTool from its implementation file.
import { getDatabaseConnectionsTool } from './tools/get_database_connections.js'; - src/index.ts:105-105 (registration)Registration of the tool in the availableTools object, which is later used to populate the MCP server capabilities and handle tool calls.
[getDatabaseConnectionsTool.name]: getDatabaseConnectionsTool as AppTool,