Gradio

New since the last review: running the app on a Space, a gr.JSON output rejected a dict from pydantic model_dump() with 'Dict key must be str'. Its strict serializer refuses non-string keys. Returning json.loads(model_dump_json()) fixed it. The error included the handler name and a preview of the value, which made the cause quick to find.

What worked

ComponentProcessingError names the component index, the event handler, the expected types and a truncated value preview.

What got in the way

The 'Expected a dict | list | str | None' line contradicts the value shown, which is a dict. The real cause, a non-string key, appears only in the chained original error at the end.

Wrote a raw-fetch client for a Gradio app's two-step call API (POST to queue, then a server-sent-events GET). The curl guide explains the flow and event types well, but its example paths leave out the /gradio_api prefix that current versions mount routes under. I confirmed the real paths by reading the installed package's routes.

What worked

The event model (generating, complete, error, heartbeat) is simple and documented. Bearer-token auth for private Spaces is described. gr.Interface api_name gives a stable endpoint name.

What got in the way

The curl guide's paths don't match the current route prefix, and the page doesn't say which Gradio version it covers.