Module chain_id

openmina_core

Module chain_id 

Source
Expand description

Chain identifier and network discrimination for Mina Protocol.

This module provides the ChainId type, which uniquely identifies different Mina blockchain networks (Mainnet, Devnet, etc.) and ensures peers only connect to compatible networks. The chain ID is computed from protocol parameters, genesis state, and constraint system digests to create a deterministic network identifier.

§Purpose

Chain IDs serve multiple critical functions in the Mina protocol:

  • Network Isolation: Prevents nodes from different networks (e.g., mainnet vs devnet) from connecting to each other
  • Protocol Compatibility: Ensures all peers use the same protocol parameters
  • Security: Used in cryptographic operations and peer authentication
  • Private Network Support: Enables creation of isolated test networks

§Chain ID Computation

The chain ID is a 32-byte Blake2b hash computed from:

  • Genesis State Hash: The hash of the initial blockchain state
  • Constraint System Digests: Hashes of the SNARK constraint systems
  • Genesis Constants: Protocol parameters like slot timing and consensus settings
  • Protocol Versions: Transaction and network protocol version numbers
  • Transaction Pool Size: Maximum transaction pool configuration

This ensures that any change to fundamental protocol parameters results in a different chain ID, preventing incompatible nodes from connecting.

§Network Identifiers

OpenMina includes predefined chain IDs for official networks:

Custom networks can compute their own chain IDs using ChainId::compute().

§Usage in Networking

Chain IDs are used throughout OpenMina’s networking stack:

  • Peer Discovery: Nodes advertise their chain ID to find compatible peers
  • Connection Authentication: WebRTC and libp2p connections verify chain ID compatibility
  • Private Networks: The preshared_key() method generates cryptographic keys for private network isolation

§Example

use openmina_core::ChainId;

// Use predefined network
let mainnet_id = openmina_core::MAINNET_CHAIN_ID;
println!("Mainnet ID: {}", mainnet_id);

// Parse from hex string
let chain_id = ChainId::from_hex("a7351abc7ddf2ea92d1b38cc8e636c271c1dfd2c081c637f62ebc2af34eb7cc1")?;

// Generate preshared key for private networking
let psk = chain_id.preshared_key();

Structs§

ChainId
Unique identifier for a Mina blockchain network.

Constants§

DEVNET_CHAIN_ID
Chain ID for the Mina development network (Devnet).
MAINNET_CHAIN_ID
Chain ID for the Mina production network (Mainnet).

Functions§

hash_genesis_constants 🔒
md5_hash 🔒

Type Aliases§

Md5 🔒