Error with extractor

[MonoPT]

When i use any extractor it gives an error:

the trait bound fn(Json) -> ... {hello_user}: OperationHandler<_, > is not satisfied
the trait OperationHandler<, _> is not implemented for fn item fn(Json) -> impl Future<Output = impl IntoApiResponse> {hello_user}
the trait OperationHandler<I, O> is implemented for Layered<L, H, T, S>
the full name for the type has been written to ...

Im following the axum example, but i cant make it past this part.

[MovingJu]

I ran into the exact same issue.

Environment:

• aide = 0.16.0-alpha2
• axum router with OpenAPI extractors

Whenever I used any axum extractor (like Query, Path, etc.), I got this error:

the trait bound fn(Json) -> ... {hello_user}: OperationHandler<_, _> is not satisfied

I was following the official axum examples, but couldn’t get past this part.

What fixed it for me

Instead of using axum extractors (Query, Path), I stopped using axum extractors entirely and handled everything via aide Json.

For example, I replaced:

• Query<T>
• Path<T>

with fields inside a Json<T> request body.

After doing this, the error completely disappeared.

If I switch back to receiving query parameters using axum extractors, however, the same OperationHandler error immediately comes back.

So this seems to be an incompatibility (or limitation) between aide 0.16.0-alpha2 and axum extractors, not an issue with the handler logic itself.

Hope this helps someone else stuck on the same problem.

[jplatte]

@MovingJu did you enable the relevant cargo features for aide?

[MovingJu]

@jplatte I hadn’t enabled the relevant cargo features before.
I just found it and enabled the axum-query feature for aide, and now the extractor works as expected. Thanks for pointing me in the right direction!

[jplatte]

@MonoPT see check if you enable aide's axum-json feature, and check if there are multiple versions of axum in your Cargo.lock.