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Relay Binary Configuration

This document describes the configuration options for the Symbiotic Relay binary, which manages validator sets and performs signature aggregation for blockchain consensus systems.

YAML Configuration Structure​

The relay binary uses a YAML configuration file with the following main sections:

Core Configuration​

# Chain URLs for EVM client connections
chain_urls:
    - "https://ethereum-rpc-url"
    - "https://backup-rpc-url"

# Driver contract address (ValSetDriver)
driver_address:
    chain_id: 1
    address: "0x..."

# Request timeout for EVM operations
request_timeout: "30s"

# Node roles (can be combined)
signer: true # Signs validator sets
aggregator: true # Aggregates signatures
committer: true # Commits to blockchain

# Polling interval for epoch detection
polling_interval: "10s"

Network Configuration​

The relay automatically retrieves network configuration from the ValSetDriver contract, including:

  • Voting Power Providers: Cross-chain addresses that provide validator voting power data
  • Keys Provider: Contract address for validator cryptographic keys
  • Replicas: Settlement contract addresses for validator set commitments
  • Verification Type: Signature aggregation method (ZK or Simple)
  • Validator Constraints: Maximum voting power, minimum inclusion threshold, max validator count
  • Key Requirements: Required cryptographic key tags and quorum thresholds

ValSetDriver and Settlement​

ValSetDriver Configuration​

The ValSetDriver contract serves as the central configuration source for the relay network.

Key parameters managed by ValSetDriver:

  • Epoch Management: Duration and timing of validator set epochs
  • Voting Power Providers: Contracts that determine validator voting power
  • Settlement Replicas: Target contracts for validator set commitments
  • Verification Parameters: Cryptographic verification settings

Settlement Integration​

The relay can commit validator sets to one or multiple settlement contracts (replicas).

Settlement configuration includes:

  • Cross-chain addresses: Chain ID and contract address pairs
  • Verification type: ZK proofs or simple aggregation
  • Quorum thresholds: Minimum voting power required for commitment

Secret Key Management​

Key Provider Interface​

The relay uses a KeyProvider interface for cryptographic operations

Supported Key Types​

The relay supports:

  • BLS BN254: For signature aggregation and ZK proofs
  • ECDSA secp256k1: For standard Ethereum signatures

Key Configuration​

key_provider:
  type: "file" | "hardware" | "remote"
  config:
    # Provider-specific configuration
    path: "/path/to/keystore"
    password_file: "/path/to/password"

Other Parameters​

Performance Tuning​

# EVM client configuration
evm_client:
  request_timeout: "30s"
  max_retries: 3
  retry_delay: "1s"

# Repository configuration
repository:
  type: "badger" | "memory"
  path: "/data/relay"

Monitoring and Metrics​

# Metrics configuration
metrics:
    enabled: true
    address: ":8080"
    path: "/metrics"

# Logging configuration  [9](#header-9)
log:
    level: "info"
    format: "json"

Node Role Configuration​

The relay supports three primary node types that can be combined:

  • Signer Nodes: Create signatures for validator sets using private keys
  • Aggregator Nodes: Collect signatures and generate aggregation proofs
  • Committer Nodes: Submit validator sets to settlement contracts

Network Discovery​

# P2P networking
p2p:
    listen_address: "/ip4/0.0.0.0/tcp/9000"
    bootstrap_peers:
        - "/ip4/bootstrap1.example.com/tcp/9000/p2p/..."

Example Configuration​

chain_urls:
    - "https://eth-mainnet.g.alchemy.com/v2/your-api-key"
driver_address:
    chain_id: 1
    address: "0x1234567890123456789012345678901234567890"
request_timeout: "30s"
polling_interval: "10s"

# Node capabilities
signer: true
aggregator: true
committer: false

# Key management
key_provider:
    type: "file"
    config:
        keystore_path: "/etc/relay/keystore"
        password_file: "/etc/relay/password"

# Storage
repository:
    type: "badger"
    path: "/var/lib/relay/data"

# Monitoring
metrics:
    enabled: true
    address: ":8080"
log:
    level: "info"