spt-p2p

P2P networking layer -- libp2p-based node with Kademlia DHT, GossipSub, mDNS, relay, and circuit breaker

Overview

spt-p2p is the peer-to-peer networking layer for the SPT platform, built on libp2p 0.54. It provides a composed swarm with GossipSub pub/sub, Kademlia DHT for content routing, mDNS for local peer discovery, relay/DCUtR for NAT traversal, and a circuit breaker state machine for resilient connections. CBOR-serialized request-response messaging and peer reputation scoring with auto-blacklisting round out the feature set.

Key Features

• libp2p swarm -- composed node with Noise encryption, Yamux multiplexing, TCP transport
• Kademlia DHT -- distributed hash table with bootstrap, content routing, and peer reputation
• GossipSub -- pub/sub messaging for topic-based broadcast
• mDNS -- zero-config local network peer discovery
• Circuit breaker -- state machine (Closed/Open/HalfOpen) for peer connection resilience
• Peer reputation -- scoring with configurable thresholds and auto-blacklisting
• Multi-hop routing -- pluggable routing strategies with path tracking

Dependencies

Key external dependencies:

• libp2p 0.54 -- core P2P networking (TCP, Noise, Yamux, GossipSub, Kademlia, mDNS, relay, DCUtR, AutoNAT)

Usage

use spt_p2p::{P2PNode, NodeConfig, NetworkMessage, MessagePriority};

let config = NodeConfig::default();
let (node, handle) = P2PNode::new(config);
// node.start().await?;

API Reference

Core Types

Type	Description
P2PNode	Main libp2p swarm node
P2PHandle	Handle for sending commands to a running node
NodeConfig	Node configuration (listen addresses, bootstrap peers)
KademliaDht	Kademlia DHT wrapper with content routing
ConnectionPool	Connection pooling with health tracking
CircuitBreaker	Per-peer circuit breaker state machine
Router	Multi-hop message router with pluggable strategies
PeerReputation	Peer scoring with auto-blacklisting
NetworkMessage	Typed network message with priority
NetworkMetrics	Latency and throughput metrics
P2pError	Crate error type

Feature Flags

Feature	Default	Description
full	yes	Enables all protocols (gossipsub + kademlia + mdns + relay)
gossipsub	no	GossipSub pub/sub only
kademlia	no	Kademlia DHT only
mdns	no	mDNS local discovery only
relay	no	Relay and DCUtR only