Module api_error 

ApiError — a handler-facing error any plain axum handler can return.

Batteries-included apps write non-CRUD handlers that touch the ORM. Without this, every one re-declares fn err500<E: Display>(e) -> (StatusCode, String) and sprinkles .map_err(err500)? on every terminal (the single highest-volume boilerplate observed in a live consumer). ApiError implements From<WriteError> / From<sqlx::Error> / From<DynError> and IntoResponse, so a handler returns Result<T, ApiError> and uses a bare ?:

use umbral::web::{ApiError, Json};

async fn get_post(Path(id): Path<i64>) -> Result<Json<Post>, ApiError> {
    let post = Post::objects().filter(post::ID.eq(id)).first().await?   // sqlx::Error -> 500
        .ok_or_else(|| ApiError::not_found("no such post"))?;           // -> 404
    Ok(Json(post))
}

Safe by default (WEB-5): a database/internal error logs the real cause server-side and hands the client an opaque 500 — table names, SQL fragments and constraint internals never reach the wire. A WriteError that is a validation failure (required field, FK-not-found, format rule, …) becomes a 400 carrying the structured per-field error map.

Enums

ApiError

A handler-facing error. Build explicit ones with the constructors, or let ? convert an ORM error (sqlx::Error / WriteError / DynError).