diff --git a/.changeset/mighty-maps-double.md b/.changeset/mighty-maps-double.md
new file mode 100644
index 0000000000000..352fd1ed11297
--- /dev/null
+++ b/.changeset/mighty-maps-double.md
@@ -0,0 +1,5 @@
+---
+"gradio": patch
+---
+
+fix:Fix multimodal chatinterface api bug
diff --git a/gradio/chat_interface.py b/gradio/chat_interface.py
index 967bebcd65fbd..c0b5d500b46ab 100644
--- a/gradio/chat_interface.py
+++ b/gradio/chat_interface.py
@@ -517,7 +517,7 @@ async def api_fn(message, history, *args, **kwargs):
         self.fake_api_btn.click(
             api_fn,
             [self.textbox, self.chatbot_state] + self.additional_inputs,
-            [self.textbox, self.chatbot_state],
+            [self.fake_response_textbox, self.chatbot_state],
             api_name="chat",
             concurrency_limit=cast(
                 Union[int, Literal["default"], None], self.concurrency_limit
@@ -697,65 +697,6 @@ async def _stream_fn(
                 history_with_input[-1] = response  # type: ignore
                 yield history_with_input
 
-    async def _api_submit_fn(
-        self,
-        message: str,
-        history: TupleFormat | list[MessageDict],
-        request: Request,
-        *args,
-    ) -> tuple[str, TupleFormat | list[MessageDict]]:
-        inputs, _, _ = special_args(
-            self.fn, inputs=[message, history, *args], request=request
-        )
-
-        if self.is_async:
-            response = await self.fn(*inputs)
-        else:
-            response = await anyio.to_thread.run_sync(
-                self.fn, *inputs, limiter=self.limiter
-            )
-        if self.type == "tuples":
-            history.append([message, response])  # type: ignore
-        else:
-            new_response = self.response_as_dict(response)
-            history.extend([{"role": "user", "content": message}, new_response])  # type: ignore
-        return response, history
-
-    async def _api_stream_fn(
-        self, message: str, history: list[list[str | None]], request: Request, *args
-    ) -> AsyncGenerator:
-        inputs, _, _ = special_args(
-            self.fn, inputs=[message, history, *args], request=request
-        )
-        if self.is_async:
-            generator = self.fn(*inputs)
-        else:
-            generator = await anyio.to_thread.run_sync(
-                self.fn, *inputs, limiter=self.limiter
-            )
-            generator = SyncToAsyncIterator(generator, self.limiter)
-        try:
-            first_response = await async_iteration(generator)
-            if self.type == "tuples":
-                yield first_response, history + [[message, first_response]]
-            else:
-                first_response = self.response_as_dict(first_response)
-                yield (
-                    first_response,
-                    history + [{"role": "user", "content": message}, first_response],
-                )
-        except StopIteration:
-            yield None, history + [[message, None]]
-        async for response in generator:
-            if self.type == "tuples":
-                yield response, history + [[message, response]]
-            else:
-                new_response = self.response_as_dict(response)
-                yield (
-                    new_response,
-                    history + [{"role": "user", "content": message}, new_response],
-                )
-
     async def _examples_fn(
         self, message: str, *args
     ) -> TupleFormat | list[MessageDict]:
diff --git a/test/test_chat_interface.py b/test/test_chat_interface.py
index 589c3440fd26b..873b2b3cece02 100644
--- a/test/test_chat_interface.py
+++ b/test/test_chat_interface.py
@@ -301,3 +301,17 @@ def test_streaming_api_with_additional_inputs(self, type, connect):
                 "robot ",
                 "robot h",
             ]
+
+    @pytest.mark.parametrize("type", ["tuples", "messages"])
+    def test_multimodal_api(self, type, connect):
+        def double_multimodal(msg, history):
+            return msg["text"] + " " + msg["text"]
+
+        chatbot = gr.ChatInterface(
+            double_multimodal,
+            type=type,
+            multimodal=True,
+        )
+        with connect(chatbot) as client:
+            result = client.predict({"text": "hello", "files": []}, api_name="/chat")
+            assert result == "hello hello"