Methanium Transport Protocol

MTP is a modular transport protocol built on QUIC. It provides version-negotiable type maps, a binary codec, cryptographic primitives (classical and post-quantum), and host/client connection management with mutual authentication.

Getting Started

Add the mtp crate with your desired features:

[dependencies]
mtp = { path = "..", features = ["client", "crypto"] }

The mtp umbrella crate re-exports all sub-crates behind feature flags:

Feature	Pulls in	Enables
crypto	mtp::crypto	AEAD, signatures, KEM, KDF, hashing
host	mtp::host, mtp::codec::registry	QUIC server, version negotiation
client	mtp::client	QUIC client connections

Core crates (codec, transport, common, type_map) are always available.

use mtp::codec::{CommunicationValue, DataValue};
use mtp::type_map::{CommunicationType, DataType, TypeMap};
use mtp::transport::{Sender, Receiver};

#[cfg(feature = "crypto")]
use mtp::crypto::ChaCha20Poly1305;

Sub-crates

All sub-crates are re-exported through the mtp facade and can be referenced as mtp::codec, mtp::transport, mtp::common, mtp::type_map, mtp::crypto, mtp::host, mtp::client.

Codec

The codec crate handles binary encoding and decoding of MTP packets using Communication Types and Data Types resolved through the type-map registry.

Data Value types:

• Container (key-value map of typed entries)
• Encrypted Container (requires crypto)
• Signed Container (requires crypto)
• SignedEncrypted Container (requires crypto)
• Signed Integer (i128)
• Unsigned Integer (u128)
• Boolean
• Float (exponent + mantissa)
• String
• Array
• Bytes
• Null

Encoding and decoding use a TypeMap to resolve type names to wire IDs. The CommunicationValue struct provides the frame format (type, flags, optional id/sender/receiver, data payload, optional signature).

Transport

The transport crate wraps QUIC using wtransport. It provides Sender/Receiver for bidirectional message passing over uni-directional QUIC streams. Supports two send modes: persistent stream and single-stream-per-message.

Host

The host crate provides MTPHost with built-in version negotiation and optional authenticated login/registration (requires crypto). Accepts connections, negotiates protocol version, and returns MTPConnection handles.

Client

The client crate provides MTPClient that connects to an MTP host. Supports connect (unauthenticated), auth_connect (login), and auth_register (registration) when built with crypto.

Common

Common defines shared error types (CodecError, CommunicationError) used across all crates.

Type Map

The type-map build script reads a YAML configuration to generate CommunicationType and DataType enums at compile time. The runtime crate provides TypeMap, Version, CommunicationTypeId, DataTypeId, and the multi-version Registry (requires registry feature).

Crypto Stack

Crate	Audited?	Notes
ml-dsa	No	NIST vectors pass; regression bug fixed Jan 2026
ed25519-dalek	Yes	Used by Signal, Diem
chacha20poly1305	Yes	NCC Group audit, Dec 2019
aes-gcm	Yes	NCC Group audit, Dec 2019
hkdf	No	Simple construction; well-reviewed
sha2	No	Standard construction; widely reviewed
zeroize	No	Simple; widely used
mlkem-tls	No	mlkem-rs backend unaudited

Test Coverage

Crate	Tests	Notes
common	7	Error type Display, Clone, format
type-map	3	Registry builtin, negotiate, latest
codec	32	DataValue roundtrip, accessors, Display, Hash, base64; CommunicationValue frame encode/decode
crypto	20	AEAD, signatures, KEM, KDF, hash, key types, multi-encrypt
transport	12	ConnectionHandle state transitions; Policy defaults; SendMode
host	3	Version extraction from messages
client	7	ClientConfig; AuthState derives
Total	84