diff --git a/packages/devtools/client/composables/client.ts b/packages/devtools/client/composables/client.ts
index 6031ed9a10..46fa973720 100644
--- a/packages/devtools/client/composables/client.ts
+++ b/packages/devtools/client/composables/client.ts
@@ -1,13 +1,14 @@
 import type { useRoute, useRouter } from '#imports'
 import type { NuxtDevtoolsClient, NuxtDevtoolsHostClient, NuxtDevtoolsIframeClient } from '@nuxt/devtools-kit/types'
 import type { Unhead } from '@unhead/schema'
+import type { DevToolsRpcClient } from '@vitejs/devtools-kit/client'
 import type { ComputedRef } from 'vue'
 import { useState } from '#imports'
 import { useColorMode } from '@vueuse/core'
 import { computed, ref } from 'vue'
 import { renderMarkdown } from './client-services/markdown'
 import { renderCodeHighlight } from './client-services/shiki'
-import { extendedRpcMap, rpc } from './rpc'
+import { connectPromise, rpc, rpcClient } from './rpc'
 
 export function useClient() {
   return useState<NuxtDevtoolsHostClient>('devtools-client')
@@ -59,13 +60,31 @@ export function useInjectionClient(): ComputedRef<NuxtDevtoolsIframeClient> {
         return renderMarkdown(code)
       },
       extendClientRpc(namespace, functions) {
-        extendedRpcMap.set(namespace, functions)
+        const register = (client: DevToolsRpcClient) => {
+          for (const [name, handler] of Object.entries(functions)) {
+            if (typeof handler === 'function') {
+              client.client.register({
+                name: `${namespace}:${name}`,
+                type: 'event',
+                handler: handler as any,
+              })
+            }
+          }
+        }
+
+        if (rpcClient.value)
+          register(rpcClient.value)
+        else
+          void connectPromise.then(register, () => {})
 
         return new Proxy({}, {
           get(_, key) {
             if (typeof key !== 'string')
               return
-            return (rpc as any)[`${namespace}:${key}`]
+            return async (...args: any[]) => {
+              const client = rpcClient.value || await connectPromise
+              return client.call(`${namespace}:${key}` as any, ...args as any)
+            }
           },
         })
       },
diff --git a/packages/devtools/client/composables/rpc.ts b/packages/devtools/client/composables/rpc.ts
index 007e2dc73d..5c05def57d 100644
--- a/packages/devtools/client/composables/rpc.ts
+++ b/packages/devtools/client/composables/rpc.ts
@@ -12,11 +12,9 @@ export const clientFunctions = {
   // will be added in setup/client-rpc.ts
 } as ClientFunctions
 
-export const extendedRpcMap = new Map<string, any>()
+export const rpcClient = shallowRef<DevToolsRpcClient>()
 
-let rpcClient: DevToolsRpcClient | undefined
-
-const connectPromise = connectDevToolsRpc()
+export const connectPromise = connectDevToolsRpc()
 
 /**
  * Proxy-based RPC object that provides backward-compatible `rpc.functionName()` interface.
@@ -25,14 +23,7 @@ const connectPromise = connectDevToolsRpc()
 export const rpc = new Proxy({} as AsyncServerFunctions, {
   get: (_, method: string) => {
     return async (...args: any[]) => {
-      const client = rpcClient || await connectPromise
-      // Check extended RPC map first for namespaced functions
-      if (method.includes(':')) {
-        const [namespace, fnName] = method.split(':') as [string, string]
-        const extFn = extendedRpcMap.get(namespace)?.[fnName]
-        if (extFn)
-          return extFn(...args)
-      }
+      const client = rpcClient.value || await connectPromise
       return client.call(method as any, ...args as any)
     }
   },
@@ -42,7 +33,7 @@ async function connectDevToolsRpc(): Promise<DevToolsRpcClient> {
   try {
     const client = await getDevToolsRpcClient()
 
-    rpcClient = client
+    rpcClient.value = client
 
     // Register client functions so the server can call them
     for (const [name, handler] of Object.entries(clientFunctions)) {
@@ -55,19 +46,6 @@ async function connectDevToolsRpc(): Promise<DevToolsRpcClient> {
       }
     }
 
-    // Register extended client RPC functions
-    for (const [namespace, fns] of extendedRpcMap) {
-      for (const [fnName, handler] of Object.entries(fns)) {
-        if (typeof handler === 'function') {
-          client.client.register({
-            name: `${namespace}:${fnName}`,
-            type: 'event',
-            handler: handler as any,
-          })
-        }
-      }
-    }
-
     // eslint-disable-next-line no-console
     console.log('[nuxt-devtools] Connected to Vite DevTools RPC')
     wsConnecting.value = false
@@ -87,7 +65,7 @@ async function connectDevToolsRpc(): Promise<DevToolsRpcClient> {
  * Used by setup/client-rpc.ts to register functions that are set up later.
  */
 export async function registerClientFunctions() {
-  const client = rpcClient || await connectPromise
+  const client = rpcClient.value || await connectPromise
   for (const [name, handler] of Object.entries(clientFunctions)) {
     if (typeof handler === 'function') {
       try {