Node binaries and ports

The zentalk-node repository ships three long-running network binaries plus operator tools. This page covers the network binaries, their ports, and the transport stack; see the CLI reference for the client and operator tools.

Binaries and default ports

Binary	Role	Main port (default)	Health/metrics port (default)
`relay`	P2P message routing, sealed-sender relay, group/channel routing, ZK auth	`-port 9001`	`-health-port`, defaults to relay port + 90 (`9091`)
`mesh-api`	Mesh storage node: DHT member + Mesh Storage API (HTTP)	`-port 9000` (DHT P2P)	`-api-port 8080` (HTTP API, includes `/health`)
`dht-bootstrap`	DHT bootstrap node for peer discovery	`-port 9000`	`-health-port 9092` (`/health`, `/metrics`, `/stats`)

The federation Docker Compose environment uses this port layout:

Service	Container port	Host port (server 1 / server 2)
DHT bootstrap (shared)	`9000`	`9000`
Relay	`9001`	`9001` / `9002`
Relay metrics	`9090`	`9091` / `9092`
Mesh P2P	`9100`	`9101` / `9102`
Mesh Storage API	`8080`	`8081` / `8082`

Independently of any compose layout, the relay’s DHT listener is always relay port + 100 (e.g. 9001 → 9101).

All three binaries load a local .env file if present and shut down gracefully on SIGINT/SIGTERM (timeout configurable via SHUTDOWN_TIMEOUT, default 30s).

relay

relay -operator 0xYourEthereumAddress -port 9001

Key flags (see relay -h for the full set):

Flag	Default	Description
`-operator`	— (required)	Operator ETH address
`-network`	`mainnet`	`mainnet` or `testnet`
`-port`	`9001`	Relay listen port
`-health-port`	port + 90	Health check HTTP port
`-key`	`./keys/relay.pem`	Private key file (RSA-4096; generated on first run)
`-genkey`	`false`	Force-generate a new key
`-mesh`	`true`	Auto-mesh formation with other relays
`-peers`	`5`	Target relay peer count for the mesh
`-bootstrap`	—	Override bootstrap DHT multiaddr
`-mesh-url`	`http://localhost:8080`	Mesh Storage API URL
`-data-dir`	`./data`	Persisted relay state (nonces, reputation)
`-enable-groups` / `-enable-channels`	`true`	Group / channel message routing
`-offline-ttl`	`2592000`	Offline queue TTL in seconds (30 days)
`-enable-zk` / `-disable-zk`	ZK on	Zero-knowledge anonymous authentication
`-zk-keys`	`./zkp-keys`	ZK setup keys directory (from `zkp-setup`)
`-zk-registry`	`./data/zkp-registry.json`	ZK user registry file
`-zk-tree-depth`	`20`	Merkle tree depth (2^20 ≈ 1M users)
`-auto-update`	`true`	DHT-announced auto-updates, applied inside `-update-start`/`-update-end` (default 02:00–06:00)

The relay persists its offline message queue in PostgreSQL (database zentalk_relay_<port> by default; override with ZENTALK_RELAY_PG_DATABASE). With ZK enabled, the verifying key from zkp-setup must exist before boot or the relay exits.

mesh-api

mesh-api -port 9100 -api-port 8080 \
  -bootstrap /dns4/bootstrap.zentalk.chat/tcp/9000/p2p/12D3Koo...

Flag	Default	Description
`-port`	`9000`	libp2p DHT port
`-api-port`	`8080`	Mesh Storage API (HTTP) port
`-data`	`./mesh-data`	Data directory
`-bootstrap`	—	Comma-separated bootstrap multiaddrs; each entry must include `/p2p/{peerID}` — unpinned entries are rejected to prevent eclipse attacks
`-cors`	`true`	CORS headers on the HTTP API
`-rate-limit`	`100`	HTTP requests per minute
`-max-upload`	`100`	Maximum upload size (MB)

In production the mesh API requires ZENTALK_JWT_SECRET at boot (it must match the API server’s secret). The HTTP surface — chunk upload/download, media chunks and manifests, username registry, network and node info — is documented in the Mesh Storage API reference. GET /health on the API port serves as the liveness check.

dht-bootstrap

dht-bootstrap -port 9000 -health-port 9092

Flag	Default	Description
`-port`	`9000`	libp2p DHT port
`-health-port`	`9092`	Health and metrics HTTP port
`-data`	`./bootstrap-data`	Data directory

The bootstrap node is the rendezvous point for peer discovery: relays and mesh nodes dial it at startup and join the shared DHT. It also answers key-bundle and file-storage RPCs.

Transport stack (libp2p)

All node binaries build on the same libp2p host configuration:

Transports — TCP listener on the configured port, with libp2p’s default transport set.
Channel security — libp2p default security: TLS 1.3 and Noise.
Peer discovery — Kademlia DHT in server mode.
NAT traversal — UPnP port mapping and AutoNAT service are always on. DCUtR hole punching and the circuit-relay-v2 client transport are enabled by default so peers behind symmetric NAT can connect; opt out per node with ZENTALK_LIBP2P_HOLEPUNCH=false or ZENTALK_LIBP2P_RELAY_CLIENT=false.
Bootstrap pinning — bootstrap multiaddrs must carry a /p2p/<PeerID> suffix; entries without a pinned peer ID are rejected.

Health and metrics endpoints

Endpoint	Served by	Content
`http://<host>:9091/health`	relay health server	Liveness + relay stats
`http://<host>:9091/topology`	relay health server	Current relay mesh topology
`http://<host>:9091/updates`	relay health server	Auto-update status
`http://<host>:8080/health`	mesh-api	Liveness
`http://<host>:9092/health`	dht-bootstrap	Liveness + peer count
`http://<host>:9092/metrics`	dht-bootstrap	Prometheus metrics
`http://<host>:9092/stats`	dht-bootstrap	Node info (peers, storage)