diff --git a/apps/builder/__tests__/webchat-message-input-origin.test.tsx b/apps/builder/__tests__/webchat-message-input-origin.test.tsx
new file mode 100644
index 000000000..c532bcd70
--- /dev/null
+++ b/apps/builder/__tests__/webchat-message-input-origin.test.tsx
@@ -0,0 +1,104 @@
+// @vitest-environment jsdom
+
+import { act, type ReactNode } from "react"
+import { createRoot, type Root } from "react-dom/client"
+import { afterEach, beforeEach, describe, expect, test, vi } from "vitest"
+
+const mocks = vi.hoisted(() => ({
+  submittedInputs: [] as Array<Record<string, unknown>>,
+  actionOptions: null as {
+    onExecute: (args: { input: Record<string, unknown> }) => void
+    onSuccess: (args: { data: null }) => void
+  } | null,
+  currentFormValues: null as Record<string, unknown> | null,
+  submit: null as (() => Promise<void>) | null,
+  clientEmbeddingOrigin: "https://www.example.com" as string | null,
+}))
+
+vi.mock("@/features/messages/actions/create-webchat-message.action", () => ({
+  createWebchatMessageAction: {},
+}))
+
+vi.mock("@next-safe-action/adapter-react-hook-form/hooks", () => ({
+  useHookFormAction: vi.fn((_action, _resolver, options) => {
+    mocks.actionOptions = options.actionProps
+    if (!mocks.currentFormValues) {
+      mocks.currentFormValues = { ...options.formProps.defaultValues }
+    }
+
+    const form = {
+      control: {},
+      formState: { isValid: true, isSubmitting: false },
+      setValue: vi.fn(),
+      reset: vi.fn((values: Record<string, unknown>) => {
+        mocks.currentFormValues = { ...values }
+      }),
+    }
+
+    const submit = async () => {
+      const input = { ...mocks.currentFormValues, text: "hello" }
+      mocks.submittedInputs.push(input)
+      mocks.actionOptions?.onExecute({ input })
+      mocks.actionOptions?.onSuccess({ data: null })
+    }
+    mocks.submit = submit
+
+    return { form, handleSubmitWithAction: submit, resetFormAndAction: vi.fn() }
+  }),
+}))
+
+vi.mock("@/features/integration-webchat/lib/authorized-domain", () => ({
+  getClientEmbeddingOrigin: () => mocks.clientEmbeddingOrigin,
+}))
+vi.mock("@/features/integration-webchat/providers/store/guest-session-provider", () => ({
+  useGuestSessionStore: (selector: (state: Record<string, unknown>) => unknown) =>
+    selector({ appendMessage: vi.fn(), guestConversationId: "guest-1", sendMessage: vi.fn() }),
+}))
+vi.mock("@chatbotx.io/ui/components/ui/form", () => ({ Form: ({ children }: { children: ReactNode }) => children }))
+vi.mock("@chatbotx.io/ui/components/ui/textarea", () => ({ Textarea: (props: Record<string, unknown>) => <textarea {...props} /> }))
+vi.mock("@chatbotx.io/ui/components/ui/button", () => ({ Button: ({ children, ...props }: Record<string, unknown>) => <button {...props}>{children as ReactNode}</button> }))
+vi.mock("react-hook-form", () => ({
+  Controller: ({ render }: { render: (args: { field: Record<string, unknown> }) => ReactNode }) => render({ field: { value: "", onChange: vi.fn() } }),
+  useWatch: ({ name }: { name: string }) => (name === "files" ? [] : ""),
+}))
+vi.mock("../src/features/messages/components/emoji-picker", () => ({ default: () => null }))
+vi.mock("../src/features/messages/components/file-upload", () => ({ FileUploadPreview: () => null }))
+vi.mock("../src/features/integration-webchat/components/webchat-message-menu", () => ({ default: () => null }))
+vi.mock("../src/features/integration-webchat/browser-profile-fields", () => ({ getWebchatProfileFields: () => ({}) }))
+
+import { WebchatMessageInput } from "../src/features/integration-webchat/webchat-message-input"
+
+describe("WebchatMessageInput embedding origin", () => {
+  let container: HTMLDivElement
+  let root: Root
+
+  beforeEach(() => {
+    mocks.submittedInputs = []
+    mocks.actionOptions = null
+    mocks.currentFormValues = null
+    mocks.submit = null
+    mocks.clientEmbeddingOrigin = "https://www.example.com"
+    container = document.createElement("div")
+    document.body.appendChild(container)
+    root = createRoot(container)
+  })
+  afterEach(() => {
+    act(() => root.unmount())
+    container.remove()
+  })
+
+  test("keeps normal origin stable across prop changes and reset", async () => {
+    const props = { workspaceId: "workspace-1", webchatId: "webchat-1", accessToken: "token", parentOrigin: "https://www.example.com" }
+    await act(async () => root.render(<WebchatMessageInput {...props} />))
+    await act(async () => root.render(<WebchatMessageInput {...props} parentOrigin="https://chat.example.com/webchat?..." />))
+    await act(async () => mocks.submit?.())
+    await act(async () => mocks.submit?.())
+    expect(mocks.submittedInputs.map((input) => input.parentOrigin)).toEqual(["https://www.example.com", "https://www.example.com"])
+  })
+
+  test("keeps null origin when client resolver returns an origin", async () => {
+    await act(async () => root.render(<WebchatMessageInput workspaceId="workspace-1" webchatId="webchat-1" parentOrigin={null} />))
+    await act(async () => mocks.submit?.())
+    expect(mocks.submittedInputs[0]?.parentOrigin).toBeUndefined()
+  })
+})
diff --git a/apps/builder/src/features/integration-webchat/webchat-message-input.tsx b/apps/builder/src/features/integration-webchat/webchat-message-input.tsx
index d927afccb..bc9bd814a 100644
--- a/apps/builder/src/features/integration-webchat/webchat-message-input.tsx
+++ b/apps/builder/src/features/integration-webchat/webchat-message-input.tsx
@@ -7,7 +7,13 @@ import { createId } from "@chatbotx.io/utils"
 import { zodResolver } from "@hookform/resolvers/zod"
 import { useHookFormAction } from "@next-safe-action/adapter-react-hook-form/hooks"
 import { PaperclipIcon, SendHorizonalIcon } from "lucide-react"
-import { type KeyboardEvent, useEffect, useMemo, useRef } from "react"
+import {
+  type KeyboardEvent,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from "react"
 import { Controller, useWatch } from "react-hook-form"
 import { createWebchatMessageAction } from "../messages/actions/create-webchat-message.action"
 import EmojiPicker from "../messages/components/emoji-picker"
@@ -15,6 +21,7 @@ import { FileUploadPreview } from "../messages/components/file-upload"
 import { createWebchatMessageRequest } from "../messages/schema/mutation"
 import { getWebchatProfileFields } from "./browser-profile-fields"
 import WebchatMessageMenu from "./components/webchat-message-menu"
+import { getClientEmbeddingOrigin } from "./lib/authorized-domain"
 import { useGuestSessionStore } from "./providers/store/guest-session-provider"
 
 type WebchatMessageInputProps = {
@@ -33,9 +40,21 @@ export const WebchatMessageInput = (props: WebchatMessageInputProps) => {
     parentOrigin,
     accessToken,
   } = props
+  const [embeddingOrigin, setEmbeddingOrigin] = useState(parentOrigin)
   const { sendMessage, guestConversationId, appendMessage } =
     useGuestSessionStore((state) => state)
 
+  useEffect(() => {
+    if (!parentOrigin) {
+      return
+    }
+
+    const clientEmbeddingOrigin = getClientEmbeddingOrigin()
+    if (clientEmbeddingOrigin) {
+      setEmbeddingOrigin(clientEmbeddingOrigin)
+    }
+  }, [])
+
   const textareaRef = useRef<HTMLTextAreaElement>(null)
   const defaultValues = useMemo(
     () => ({
@@ -47,14 +66,14 @@ export const WebchatMessageInput = (props: WebchatMessageInputProps) => {
       ref: referral,
       ...getWebchatProfileFields(),
       accessToken: accessToken ?? undefined,
-      parentOrigin: parentOrigin ?? undefined,
+      parentOrigin: embeddingOrigin ?? undefined,
     }),
     [
       workspaceId,
       webchatId,
       guestConversationId,
       referral,
-      parentOrigin,
+      embeddingOrigin,
       accessToken,
     ],
   )
@@ -186,7 +205,7 @@ export const WebchatMessageInput = (props: WebchatMessageInputProps) => {
             <div className="flex-1">
               <WebchatMessageMenu
                 accessToken={accessToken}
-                parentOrigin={parentOrigin}
+                parentOrigin={embeddingOrigin}
                 webchatId={webchatId}
                 workspaceId={workspaceId}
               />