[Misc] Make gradio an optional dependency and upgrade to >=6.7.0 (#2221)

Signed-off-by: Lidang-Jiang <lidangjiang@gmail.com>
Signed-off-by: Lidang Jiang <lidangjiang@gmail.com>

docs/getting_started/installation/gpu/cuda.inc.md

@@ -29,6 +29,11 @@ uv pip install vllm --torch-backend=auto
 uv pip install vllm-omni
 ```
 
+To run Gradio demos, also install the optional extras:
+```bash
+uv pip install 'vllm-omni[demo]'
+```
+
 # --8<-- [end:pre-built-wheels]
 
 # --8<-- [start:build-wheel-from-source]
@@ -50,6 +55,11 @@ cd vllm-omni
 uv pip install -e .
 ```
 
+To run Gradio demos, install with optional extras:
+```bash
+uv pip install -e '.[demo]'
+```
+
 <details><summary>(Optional) Installation of vLLM from source</summary>
 If you want to check, modify or debug with source code of vLLM, install the library from source with the following instructions:
 

docs/user_guide/examples/offline_inference/text_to_image.md

@@ -256,6 +256,15 @@ lora_adapter/
 
 ## Web UI Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 Launch the Gradio demo:
 
 ```bash

docs/user_guide/examples/online_serving/fish_speech.md

@@ -11,6 +11,15 @@ Source <https://github.com/vllm-project/vllm-omni/tree/main/examples/online_serv
 
 ## Gradio Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 An interactive Gradio demo is available with text-to-speech synthesis, voice cloning, and streaming support.
 
 ```bash

docs/user_guide/examples/online_serving/image_to_image.md

@@ -122,6 +122,15 @@ python openai_chat_client.py --input input1.png input2.png --prompt "Combine the
 
 ### Method 4: Using Gradio Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 ```bash
 python gradio_demo.py
 # Visit http://localhost:7861

docs/user_guide/examples/online_serving/qwen2_5_omni.md

@@ -149,6 +149,15 @@ python openai_chat_completion_client_for_multimodal_generation.py \
 
 ## Run Local Web UI Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 This Web UI demo allows users to interact with the model through a web browser.
 
 ### Running Gradio Demo

docs/user_guide/examples/online_serving/qwen3_omni.md

@@ -163,6 +163,15 @@ python openai_chat_completion_client_for_multimodal_generation.py \
 
 ## Run Local Web UI Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 This Web UI demo allows users to interact with the model through a web browser.
 
 ### Running Gradio Demo

docs/user_guide/examples/online_serving/qwen3_tts.md

@@ -19,6 +19,15 @@ Please refer to [README.md](https://github.com/vllm-project/vllm-omni/tree/main/
 
 ## Gradio Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 Two interactive Gradio demos are available, both supporting all 3 task types:
 
 | Demo     | File                     | Transport    | Streaming Quality                                  |

docs/user_guide/examples/online_serving/text_to_image.md

@@ -105,6 +105,15 @@ python openai_chat_client.py --prompt "A beautiful landscape painting" --output
 
 ### Method 4: Using Gradio Demo
 
+!!! note "Gradio is an optional dependency"
+    The Gradio demo requires the `[demo]` extras. Install them first:
+
+    ```bash
+    pip install 'vllm-omni[demo]'
+    ```
+
+    Or, if installing from source: `pip install -e '.[demo]'`
+
 ```bash
 python gradio_demo.py
 # Visit http://localhost:7860