refactor: consolidate duplicated cross-cutting constants

server/mcp.ts

@@ -17,17 +17,18 @@ import { getAgentPermissions, type Permission } from './lib/iam'
 import { detectRequiredPermissions } from './lib/sql-permissions'
 import { buildExecutableSql, formatExecutionError } from './lib/execute-sql'
 import { auditSQL } from './lib/audit'
+import { MCP_CATALOG_PAGE_SIZE, MCP_MAX_RESULT_ROWS } from '../src/lib/constants'
 
 declare const __APP_VERSION__: string
 
 export const MCP_PATH = '/mcp'
-const PAGE_SIZE = 100
+const PAGE_SIZE = MCP_CATALOG_PAGE_SIZE
 
 // Hard cap on rows returned by the execution tools, so a broad SELECT can't flood an agent's
 // context. The full result is fetched, then capped; a `truncated` flag tells the agent to narrow
 // (LIMIT/WHERE or a smaller maxRows). MCP only — the UI route is intentionally uncapped because it
 // needs the full result set for CSV export and inline editing.
-export const MAX_RESULT_ROWS = 1000
+export const MAX_RESULT_ROWS = MCP_MAX_RESULT_ROWS
 
 // A resolved MCP caller — identity + audit actor for one agent. Permission resolution
 // itself lives in iam.ts (getAgentPermissions), the single home for that decision.

server/services/query-service.ts

@@ -9,6 +9,7 @@ import { hasPermission, requirePermission, requirePermissions, requireAnyPermiss
 import { detectRequiredPermissions } from "../lib/sql-permissions";
 import { buildExecutableSql, formatExecutionError } from "../lib/execute-sql";
 import { auditSQL, auditExport, listAuditEvents, listSystemAuditEvents, type AuditEvent } from "../lib/audit";
+import { AUDIT_LOG_FETCH_LIMIT, AUDIT_LOG_DEFAULT_LIMIT } from "../../src/lib/constants";
 
 // Track active queries by queryId -> { pid, connectionDetails, email }
 const activeQueries = new Map<string, { pid: number; details: ConnectionDetails; email: string }>();
@@ -1223,7 +1224,7 @@ export const queryServiceHandlers: ServiceImpl<typeof QueryService> = {
     requirePermission(user, req.connectionId, 'admin', 'view audit log');
     getConnectionDetails(req.connectionId);
 
-    const limit = req.limit > 0 ? Math.min(req.limit, 1000) : 100;
+    const limit = req.limit > 0 ? Math.min(req.limit, AUDIT_LOG_FETCH_LIMIT) : AUDIT_LOG_DEFAULT_LIMIT;
     const entries = listAuditEvents(req.connectionId, limit).map(toAuditLogEntry);
 
     return { entries };
@@ -1241,7 +1242,7 @@ export const queryServiceHandlers: ServiceImpl<typeof QueryService> = {
       throw new ConnectError("Permission denied: viewing the system audit log requires instance owner", Code.PermissionDenied);
     }
 
-    const limit = req.limit > 0 ? Math.min(req.limit, 1000) : 100;
+    const limit = req.limit > 0 ? Math.min(req.limit, AUDIT_LOG_FETCH_LIMIT) : AUDIT_LOG_DEFAULT_LIMIT;
     const entries = listSystemAuditEvents(limit).map(toAuditLogEntry);
 
     return { entries };

src/hooks/useQuery.ts

@@ -1,5 +1,6 @@
 import { useMutation, useQuery, useQueryClient, type QueryClient } from '@tanstack/react-query';
 import { queryClient, connectionClient, aiClient } from '../lib/connect-client';
+import { AUDIT_LOG_FETCH_LIMIT, LIVE_QUERY_REFETCH_INTERVAL_MS } from '../lib/constants';
 import type { ColumnMetadata } from '../components/sql-editor/hooks/useEditorTabs';
 
 // Query keys
@@ -309,7 +310,7 @@ export function useActiveProcesses(connectionId: string, enabled = true) {
       return response.sessions;
     },
     enabled: enabled && !!connectionId,
-    refetchInterval: 5000,
+    refetchInterval: LIVE_QUERY_REFETCH_INTERVAL_MS,
   });
 }
 
@@ -328,17 +329,15 @@ export function useTerminateProcess() {
   });
 }
 
-const AUDIT_LOG_LIMIT = 1000;
-
 export function useAuditLogEntries(connectionId: string, enabled = true) {
   return useQuery({
     queryKey: queryKeys.auditLog(connectionId),
     queryFn: async () => {
-      const response = await queryClient.getAuditLogEntries({ connectionId, limit: AUDIT_LOG_LIMIT });
+      const response = await queryClient.getAuditLogEntries({ connectionId, limit: AUDIT_LOG_FETCH_LIMIT });
       return response.entries;
     },
     enabled: enabled && !!connectionId,
-    refetchInterval: 5000,
+    refetchInterval: LIVE_QUERY_REFETCH_INTERVAL_MS,
   });
 }
 
@@ -348,11 +347,11 @@ export function useSystemAuditLogEntries(enabled = true) {
   return useQuery({
     queryKey: queryKeys.systemAuditLog(),
     queryFn: async () => {
-      const response = await queryClient.getSystemAuditLogEntries({ limit: AUDIT_LOG_LIMIT });
+      const response = await queryClient.getSystemAuditLogEntries({ limit: AUDIT_LOG_FETCH_LIMIT });
       return response.entries;
     },
     enabled,
-    refetchInterval: 5000,
+    refetchInterval: LIVE_QUERY_REFETCH_INTERVAL_MS,
   });
 }
 

src/lib/constants.ts

@@ -0,0 +1,39 @@
+// Centralized home for cross-cutting and otherwise-duplicated constants.
+//
+// Keep this file dependency-free (pure values only) so both the client and the
+// server can import it without dragging browser- or server-only code across the
+// boundary. Feature-local constants that are used in exactly one place and are
+// already well-named should stay next to their feature — only values that are
+// duplicated, span the client/server boundary, or define a runtime contract
+// belong here.
+
+// --- Audit log ---
+
+/**
+ * Max audit-log rows fetched per tab, and the server-side hard clamp on the
+ * `limit` request field. The client request and the server clamp must agree, so
+ * they share this single source of truth.
+ */
+export const AUDIT_LOG_FETCH_LIMIT = 1000
+
+/** Server default applied when an audit-log request omits a positive `limit`. */
+export const AUDIT_LOG_DEFAULT_LIMIT = 100
+
+// --- Live polling ---
+
+/**
+ * Refetch cadence (ms) for client queries that poll live data — active sessions
+ * and the audit-log tabs.
+ */
+export const LIVE_QUERY_REFETCH_INTERVAL_MS = 5000
+
+// --- MCP server ---
+
+/**
+ * Hard cap on rows an MCP execution tool returns. The full result is fetched,
+ * then capped; when capped the response sets `truncated` so the agent can narrow.
+ */
+export const MCP_MAX_RESULT_ROWS = 1000
+
+/** Page size for MCP catalog browsing (`list_objects` pagination). */
+export const MCP_CATALOG_PAGE_SIZE = 100