Springtime could use declarative HTTP client generation similar to OpenFeign. It should create implementations, based on traits with attributes, and integrate with the rest of Springtime ecosystem (e.g. using the same default config file).

I have a custom constructor with a very basic example, but it consistently results in the following error:

#[derive(Component)]
| ^^^^^^^^^
| |
| Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>> is not a future
| this call returns Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>>
|
= help: the trait Future is not implemented for Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>>, which is required by Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>>: IntoFuture
= note: Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>> must be a future or must implement IntoFuture to be awaited
= note: required for Result<HandlebarsEngineImpl, Arc<dyn StdError + Send + Sync>> to implement IntoFuture