Networking

Fully peer-to-peer using libp2p. No central servers.

Components

Component	Purpose	Protocol
Host	TCP transport, connection management	libp2p core
GossipSub	Broadcast blocks, votes, marketplace, statechain, directory	libp2p GossipSub
Sync	Frontier-based block synchronization	`/xe/sync/1.0.0`
Messaging	Request-response over streams	`/xe/msg/1.0.0`
DHT	Kademlia peer discovery	`/xe` prefix

Discovery Mechanisms

mDNS — automatic local network discovery
Bootstrap peers — explicit via -dial flag, retry every 10s
Kademlia DHT — distributed hash table with /xe prefix

GossipSub Topics

Topic	Data Type	Buffer
`xe/blocks`	Block	256
`xe/votes`	Vote	256
`xe/marketplace`	MarketplaceMsg	256
`xe/statechain`	StateChainBlock	16
`xe/directory`	Registration	256
`xe/certificates`	Certificate	64

Max gossip message size: 256 KB.

Sync Protocol

Frontier-based: exchange account → latest block hash
Paginated responses (default 64 blocks/page, max 256)
Max 10,000 blocks per sync session
5-second per-peer cooldown
Periodic re-sync every 10 seconds (with dirty flag optimization)
Cross-account dependency retry (up to 3 passes)
Block quarantine for permanently invalid blocks

Messaging Protocol

Request-response semantics
30-second stream deadline
64 KB max request/response
Message types: vm_credentials, vm_status, account_chat, attest_timestamp
DHT-based peer discovery fallback

Security

Transport encryption (Noise or TLS 1.3)
Persistent Ed25519 identity
GossipSub pre-validates field lengths
Sync rate limiting (5s per peer)
Max message sizes enforced

Host Configuration

TCP on all interfaces, configurable port
Connection manager: low=100, high=400, grace=1min
Persistent identity at {dataDir}/host.key
Optional relay + hole-punching support