Miden Objects

Canonical Protobuf representations for values exchanged between Miden clients and nodes.

This crate owns the transport representation and conversions for protocol objects. It does not define protocol commitments, replace the protocol's native serialization, or define RPC services. Generated messages are exposed under miden_objects::proto.

The crate supports no_std consumers when default features are disabled.

RPC crates can use FILE_DESCRIPTOR_SET as the import descriptor and apply every entry in EXTERN_PATHS with prost_build::Config::extern_path. This makes imported object messages resolve to the canonical generated types from this crate instead of generating duplicate Rust types in the RPC crate.

Decoded Objects

The experimental ProtoDecodeFields derive generates schema-shaped records, required/optional/ repeated message conversion, and nested field/index error paths. Atomic messages can implement DecodeMessage using their existing representation decoder. Enum fields use Prost's named enum types, preserving optional/repeated cardinality and rejecting unknown discriminants with generated paths. Known variants such as Unspecified remain available for domain verification. Oneofs generate matching decoded enums, with exact wire variant names supplied by descriptors. An absent oneof is rejected by default; an explicitly configured optional oneof retains its Option. Maps and boxed messages are not yet supported and are not used by these schemas.

The three single-payload atoms use ProtoDecodeValue to generate decode_value(&self, parser). Their parsers return representation errors; the helper supplies the payload field path and preserves the source. Neither targets nor constructors are configured in attributes.

Canonical bytes can opt into a local representation type using #[proto_decode(bytes = Adapter)]. The adapter implements ordinary TryFrom; generated code supplies field, variant, and index paths. It does not run domain verification.

Domain construction is opt-in and handwritten: Verify::verify() needs no external context, VerifyWith<C>::verify_with(context) accepts borrowed or owned context, and BuildUnchecked::build_unchecked() uses a supported unchecked constructor. Unchecked construction can still fail and must document the invariants the caller must ensure. None of these operations is invoked automatically by field decoding, and verification errors do not get generated wire paths. Direct protobuf-to-domain TryFrom/From conversions and combined decoding helpers are intentionally unavailable for generated records. Callers must decode the fields and explicitly select a construction capability; only atomic representation adapters retain their TryFrom implementations.

All 98 Miden messages are integrated: 95 generated records and three canonical atomic adapters. Construction capabilities, trust boundaries, and unreleased wire changes are detailed in Decoded Conversion Migration.

License

This project is MIT licensed.