chains - EVM-Based Chain Data Management for Enhanced Chain Integration

Introduction to EVM-based Chains

EVM-based chains are a fascinating aspect of blockchain technology, rooted in the Ethereum Virtual Machine (EVM). This guide provides an overview of the essential components and features of these chains, utilizing a structured format to ensure clarity and comprehension.

Structure and Data Storage

Each chain within the EVM ecosystem is stored in a separate file format, adhering to the naming convention prescribed by the CAIP-2 standards. These files are formatted as .json and contain crucial information about the chain's attributes.

Example Structure

A typical JSON file for a chain might appear as follows:

{
  "name": "Ethereum Mainnet",
  "chain": "ETH",
  "rpc": [
    "https://mainnet.infura.io/v3/${INFURA_API_KEY}",
    "https://api.mycryptoapi.com/eth"
  ],
  "faucets": [],
  "nativeCurrency": {
    "name": "Ether",
    "symbol": "ETH",
    "decimals": 18
  },
  "features": [{ "name": "EIP155" }, { "name": "EIP1559" }],
  "infoURL": "https://ethereum.org",
  "shortName": "eth",
  "chainId": 1,
  "networkId": 1,
  "icon": "ethereum",
  "explorers": [{
    "name": "etherscan",
    "url": "https://etherscan.io",
    "icon": "etherscan",
    "standard": "EIP3091"
  }]
}

Key Components

RPC URLs: These are endpoints that allow interaction with the blockchain network. They are critical for developers and users who wish to engage with the blockchain.
Native Currency: Each chain has its native currency, typically defined by its name, symbol, and decimal places. For Ethereum, this is Ether (ETH).
Features: Chains can support different Ethereum Improvement Proposals (EIPs) which introduce new capabilities. For instance, EIP155 and EIP1559 might be noted.
Explorer: Each chain usually has multiple blockchain explorers, such as Etherscan, for viewing transactions and activities on the network.
Icons: Visual identifiers for chains or explorers are stored in JSON files under _data/icons, ensuring easily recognizable branding.

Compatibility and Structure

If a chain is part of another (such as Layer 2 solutions or shards), it can be linked with its parent chain using a structured JSON object. This allows for complex network structures to be effectively managed and referenced.

{
  ...
  "parent": {
    "type": "L2",
    "chain": "eip155-1",
    "bridges": [{"url":"https://bridge.arbitrum.io"}]
  }
}

Unique Identifiers and Constraints

Each chain must have a unique shortName and name for identification as per EIP-3770 guidelines.
Chains must not share the same chainId to avoid replay attacks.

Process for Integration

Before submitting new chain data or updates, it's essential to ensure that all checks are passed using specific testing commands. Once submitted, continuous integration (CI) processes must be verified, ensuring smooth integration and review.

Usage and Ecosystem

EVM-based chains participate in a vast ecosystem, providing tools like MESC, explorers like Otterscan, and wallets such as TREZOR. Moreover, several resources offer additional information and lists of chains, such as chainid.network and chainlist.org.

In summary, EVM-based chains offer a robust, flexible framework for creating and managing blockchain networks. By understanding their structure, constraints, and integration processes, developers and users can maximize their potential within this innovative ecosystem.