Struct ErrorEnvelopeLayer 

pub struct ErrorEnvelopeLayer;

Tower layer that converts error responses into a production error envelope.

Non-error responses pass through unchanged. 4xx and 5xx responses are converted to:

{
  "error": {
    "statusCode": 400,
    "code": "bad_request",
    "message": "invalid input",
    "details": null,
    "timestamp": "2026-01-01T00:00:00Z",
    "path": "/users",
    "requestId": "..."
  }
}

Legacy/simple Nidus bodies shaped like { "error": { "code": "...", "message": "...", ... } } are parsed and wrapped. Extra fields under error are preserved as details for non-5xx responses. For all 5xx responses, the client-facing message is masked to "internal server error" and details is set to null. Error bodies larger than 64 KiB are not parsed as legacy JSON; oversized bodies are replaced with the status-derived envelope to avoid unbounded buffering.

When crate::context::RequestContext is present, its request ID is copied into error.requestId; otherwise that field is an empty string. Install the validated request ID and request context layers, or use crate::middleware::ApiDefaults::production, when clients need stable request IDs in error responses.

Implementations

impl ErrorEnvelopeLayer

pub fn new() -> Self

Creates an error envelope layer.

Trait Implementations

impl Clone for ErrorEnvelopeLayer

fn clone(&self) -> ErrorEnvelopeLayer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ErrorEnvelopeLayer

impl Debug for ErrorEnvelopeLayer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ErrorEnvelopeLayer

fn default() -> ErrorEnvelopeLayer

Returns the “default value” for a type.

impl<S> Layer<S> for ErrorEnvelopeLayer

type Service = ErrorEnvelopeService<S>

The wrapped service

fn layer(&self, inner: S) -> Self::Service

Wrap the given service with the middleware, returning a new service that has been decorated with the middleware.