diff --git a/ui/src/api/queries/commands.ts b/ui/src/api/queries/commands.ts
index 853c447f..0e24dce6 100644
--- a/ui/src/api/queries/commands.ts
+++ b/ui/src/api/queries/commands.ts
@@ -4,6 +4,18 @@ import { useAuthStore } from '../../auth/auth-store'
 
 // ── Application Config ────────────────────────────────────────────────────
 
+export interface TapDefinition {
+  tapId: string
+  processorId: string
+  target: 'INPUT' | 'OUTPUT' | 'BOTH'
+  expression: string
+  language: string
+  attributeName: string
+  attributeType: 'BUSINESS_OBJECT' | 'CORRELATION' | 'EVENT' | 'CUSTOM'
+  enabled: boolean
+  version: number
+}
+
 export interface ApplicationConfig {
   application: string
   version: number
@@ -14,6 +26,10 @@ export interface ApplicationConfig {
   metricsEnabled: boolean
   samplingRate: number
   tracedProcessors: Record<string, string>
+  taps: TapDefinition[]
+  tapVersion: number
+  routeRecording: Record<string, boolean>
+  compressSuccess: boolean
 }
 
 /** Authenticated fetch using the JWT from auth store */
@@ -87,3 +103,61 @@ export function useSendGroupCommand() {
     },
   })
 }
+
+// ── Test Expression ───────────────────────────────────────────────────────
+
+export function useTestExpression() {
+  return useMutation({
+    mutationFn: async ({
+      application,
+      expression,
+      language,
+      body,
+      target,
+    }: {
+      application: string
+      expression: string
+      language: string
+      body: string
+      target: string
+    }) => {
+      const res = await authFetch(
+        `/api/v1/config/${encodeURIComponent(application)}/test-expression`,
+        {
+          method: 'POST',
+          headers: { 'Content-Type': 'application/json' },
+          body: JSON.stringify({ expression, language, body, target }),
+        },
+      )
+      if (!res.ok) {
+        if (res.status === 404) throw new Error('No live agent available')
+        if (res.status === 504) throw new Error('Expression test timed out')
+        throw new Error('Failed to test expression')
+      }
+      return res.json() as Promise<{ result?: string; error?: string }>
+    },
+  })
+}
+
+// ── Replay Exchange ───────────────────────────────────────────────────────
+
+export function useReplayExchange() {
+  return useMutation({
+    mutationFn: async ({
+      agentId,
+      headers,
+      body,
+    }: {
+      agentId: string
+      headers: Record<string, string>
+      body: string
+    }) => {
+      const { data, error } = await api.POST('/agents/{id}/commands', {
+        params: { path: { id: agentId } },
+        body: { type: 'replay', payload: { headers, body } } as any,
+      })
+      if (error) throw new Error('Failed to send replay command')
+      return data!
+    },
+  })
+}