Crate aerro 

Cross-service gRPC errors for Rust.

aerro gives every error a typed identity, a bounded call trace, and a structured wire encoding. Derive Aerro on an error enum, call IntoStatus to encode it into a tonic::Status, and TryFromStatus on the client to recover the original variant — with the full chain of service hops attached.

Quick Example

use aerro::{Aerro, IntoStatus, StatusIntoResultExt};

#[derive(Debug, aerro::Aerro)]
pub enum CreateUserError {
    #[aerro(category = Business, code = AlreadyExists, error = "email already taken: {email}")]
    EmailTaken { email: String },

    #[aerro(category = System, code = Internal, error = "db.unavailable")]
    DbUnavailable,
}

// Server side
let err = CreateUserError::EmailTaken { email: "alice@example.com".into() };
let status = err.into_status_default();

// Client side — recover the typed variant
let recovered = status.into_aerro::<CreateUserError>().unwrap();

Feature Flags

Flag	Default	Description
macro	✓	Aerro derive macro
tracing	✗	Capture OTel trace/span IDs via the tracing subscriber

Key Types

• Aerro — the trait every error type implements (derive or manual)
• ServiceFailure<E> — typed error + frames + trace
• RemoteError — type-erased fallback for errors from unknown services
• Frame — one hop in the call chain
• TraceContext — OTel trace/span IDs
• EncodeOptions — egress configuration (exposure tier, frame cap)

Re-exports

pub use any::render_chain;

pub use category::Category;

pub use error::DecodeError;

pub use error::EncodeError;

pub use exposure::Exposure;

pub use failure::ServiceFailure;

pub use frame::Frame;

pub use remote::RemoteError;

pub use trace::TraceContext;

pub use traits::Aerro;

pub use ext::ResultIntoStatusExt;

pub use ext::StatusIntoResultExt;

pub use traits::IntoStatus;

pub use traits::TryFromStatus;

pub use wire::decode::decode;

pub use wire::encode::EncodeOptions;

pub use wire::encode::encode;

Modules

any

Error chain rendering utility.

category

Variant taxonomy — see spec §8.

error

Decode/encode error types — see spec §5.

exposure

Exposure tiers — see spec §9.

ext

Convenience extension traits for sites that want neither layer nor macro.

failure

ServiceFailure<E> — typed error plus accumulated trace.

frame

One hop in the call trace — see spec §7.

remote

Type-erased fallback for unknown wire types — see spec §5.

trace

OpenTelemetry trace and span IDs carried on every error envelope.

traits

wire

Wire envelope (bincode) + encode/decode glue.

Constants

VERSION

Current crate version.

Derive Macros

Aerro

Derive the aerro::Aerro trait for an error enum.