Derive support for composing EIP-2718 transaction-envelope enums. This crate is normally consumed through alloy-consensus, which re-exports TransactionEnvelope and forwards its serde and arbitrary features.

use alloy_consensus::{Signed, TransactionEnvelope, TxEip1559};

#[derive(Clone, Debug, TransactionEnvelope)]
#[envelope(tx_type_name = MyTxType, typed = MyTypedTransaction)]
pub enum MyEnvelope {
    #[envelope(ty = 2)]
    Eip1559(Signed<TxEip1559>),
}

The numeric attribute is a dispatch declaration, not an encoding override: the inner type's Typed2718, encoder, and decoder must already use the same ID. Valid EIP-2718 type bytes are at most 0x7f; although the macro and generated RLP codec accept any u8, larger IDs are invalid and not interoperable with standard raw EIP-2718 decoding.

When the derive is imported through the alloy meta crate rather than a direct alloy-consensus dependency, point generated paths at the re-export:

#[derive(Clone, Debug, alloy::consensus::TransactionEnvelope)]
#[envelope(alloy_consensus = alloy::consensus, tx_type_name = MyTxType)]
enum MyEnvelope {
    // ...
}