gr.Video and gr.Image break API schema on ZeroGPU Spaces (Gradio 5.0.0)

[pelegs202-design]

Hi! I'm building a HuggingFace Space on ZeroGPU and hitting a frustrating bug where using gr.Video, gr.Image, gr.Audio, or gr.JSON as inputs/outputs completely breaks the Gradio API.

Environment:

• HF Space: https://huggingface.co/spaces/somebeast/tribe-v2
• Gradio 5.0.0 (from the ZeroGPU base image)
• Python 3.12 (also reproduced on 3.10)
• Hardware: zero-a10g

The bug:
When any of these components are used as outputs in gr.Blocks, the /gradio_api/call/<api_name> endpoint returns event: error with data: null. The Gradio client also fails to connect with:

TypeError: argument of type 'bool' is not iterable

The traceback points to gradio_client/utils.py line 882 in get_type:

if "const" in schema:  # <-- schema is a bool, not a dict

Minimal repro:

import gradio as gr

def analyze(text):
    return "scores here", "path/to/chart.png", "insight"

with gr.Blocks() as demo:
    inp = gr.Textbox()
    btn = gr.Button("Go")
    out1 = gr.Textbox()
    out2 = gr.Image(type="filepath")  # <-- adding this breaks ALL API endpoints
    out3 = gr.Textbox()
    btn.click(analyze, [inp], [out1, out2, out3], api_name="predict")

demo.queue().launch()

Workaround:
Using only gr.Textbox inputs and outputs makes everything work fine — API, client, web UI. But that means no image/video/audio components at all, which defeats the purpose of having a rich UI.

What I've tried:

• gr.Blocks instead of gr.Interface — same bug
• Python 3.10 and 3.12 — same bug on both
• Explicit api_name on every function — doesn't help
• type="filepath" on gr.Image — same bug

Is this a known issue with the ZeroGPU base image's Gradio version? Is there a fix or a newer Gradio version that works on ZeroGPU?

[abidlabs]

Yes any recent version of Gradio should work with ZeroGPU, can you try upgrading the sdk_version here: https://huggingface.co/spaces/somebeast/tribe-v2/blob/main/README.md?

[pelegs202-design]

Quick update -- tried upgrading to sdk_version: "5.25.0" as suggested. The web UI loads fine but the API schema bug persists.

Specifically:

• Endpoints with only gr.Textbox outputs work perfectly via /gradio_api/call/
• Endpoints with gr.Image(type="filepath") as an output return event: error, data: null
• Same Space, same app, just whether gr.Image is in the output list

So it is definitely the gr.Image component breaking API schema generation, not a general ZeroGPU issue. Tested on both Python 3.10 and 3.12, Gradio 5.0.0 and 5.25.0 -- same behavior.

[abidlabs]

What about the latest version of Gradio, 6.11?

[pelegs202-design]

Just tried Gradio 6.11.0 -- same issue. The /gradio_api/call/predict endpoint returns event: error with null data when gr.Image(type="filepath") is in the outputs list.

To be clear, the web UI works fine on all versions. Its only the API that breaks.

Here is what I see:

• sdk_version: "6.11.0" in README.md
• Python 3.12 on ZeroGPU
• POST to /gradio_api/call/predict returns event_id successfully (200)
• GET to /gradio_api/call/predict/{event_id} returns "event: error" + "data: null"
• If I swap gr.Image to gr.Textbox in the same output list, it works perfectly

Happy to give you access to the Space if that helps debug: https://huggingface.co/spaces/somebeast/tribe-v2