# Project State: ant-quic Multi-Transport Core

## Current Position
- **Status**: COMPLETED
- **Milestone**: multi-transport-core
- **Phase**: completed

## Summary

Successfully implemented the multi-transport abstraction layer based on `docs/research/CONSTRAINED_TRANSPORTS.md:233-964`.

## Completed Deliverables

### New Files Created
1. `src/transport/addr.rs` - TransportAddr enum with UDP, BLE, LoRa, Serial, AX.25, I2P, Yggdrasil support
2. `src/transport/capabilities.rs` - TransportCapabilities with bandwidth profiles
3. `src/transport/provider.rs` - TransportProvider trait and TransportRegistry
4. `src/transport/udp.rs` - UDP transport provider implementation
5. `src/transport/ble.rs` - BLE transport provider (feature-gated with `ble` feature)
6. `src/transport/mod.rs` - Updated module with full exports

### NodeConfig Extensions
- Added `transport_providers: Vec<Arc<dyn TransportProvider>>` field
- Added `build_transport_registry()` method
- Added `has_constrained_transports()` method
- Updated builder with `transport_provider()` and `transport_providers()` methods

### Feature Flags Added
- `ble` - Enables Bluetooth Low Energy transport (Linux only, requires BlueZ)

### Key Features Implemented
1. **TransportAddr** - Unified addressing across all transport types
2. **TransportCapabilities** - Bandwidth/MTU/RTT profiles for protocol selection
3. **TransportProvider trait** - Async send/receive with capability reporting
4. **ProtocolEngine selector** - QUIC vs Constrained engine selection
5. **TransportRegistry** - Collection and lookup of transport providers
6. **TransportDiagnostics** - Runtime diagnostics for path selection
7. **BLE PQC mitigations** - Session caching and resume tokens

## Test Results
- All 1160 library tests pass
- 69 new transport-specific tests
- Zero clippy warnings
- Zero compilation warnings

## Next Steps (Future Work)
- Integrate transport registry with Node/P2pEndpoint
- Implement constrained protocol engine
- Add LoRa transport provider
- Implement gateway architecture for cross-transport routing
