4 KiB
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 |