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Run Chain examples in the interactive playground

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Chain

Ethereum chain configuration objects with network metadata, RPC endpoints, and explorer information.
Learn about chain IDs, replay attack prevention, and network identification in the Fundamentals guide.

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Overview

Branded type representing Ethereum chain configurations. Provides chain constants, metadata, and lookup utilities for Ethereum networks. Zero-overhead design supports both tree-shakeable namespace methods and class instances.

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Quick Start

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    Types

    class Chain {
  // Constructors (→ /primitives/chain/constructors)
  static from(chain: Chain): Chain
  static fromId(id: number): Chain | undefined

  // Lookup (→ /primitives/chain/chain-lookup)
  static byId: Record<number, Chain>
}
    Source: Chain.js:14-36

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    Chain Constants

    Chain objects imported from @tevm/chains: 
    import {
  // Mainnets
  flr14,
  quai9,
  injective1776,
  ronin2020,
  moca2288,

  // Popular networks (via chain ID)
  // Use Chain.fromId(id) or Chain.byId[id]
} from '@tevm/chains'

// Access chain metadata
console.log(quai9.name)          // "Quai Mainnet"
console.log(quai9.chainId)       // 9
console.log(quai9.nativeCurrency.symbol) // "QUAI"

// Use with Chain constructor
const chain = Chain(quai9)
    Available constants:
    • 800+ chain configurations from @tevm/chains
    • Includes testnets, mainnets, L2s, and sidechains
    • Each constant includes full metadata (RPC, explorer, currency)
    See @tevm/chains documentation for complete list.

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    API Methods

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    Core Operations

    • fundamentals - Learn chain IDs, replay attack prevention, and network identification
    • constructors - Create Chain instances from chain objects and chain IDs
    • chain-lookup - Look up chains by ID using fromId() and byId record
    • metadata - Access chain properties: name, chainId, RPC, explorers, currency

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    Advanced Features

    Chain is a lightweight wrapper around plain JavaScript objects from @tevm/chains. The Chain class adds prototype methods while keeping the underlying data structure simple and serializable.

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    Address

    Ethereum address type for contract and account addresses. View Address →

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    Branded Types

    Zero-overhead type branding pattern used throughout primitives. View Branded Types →

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    Denomination

    Wei, Gwei, and Ether types with currency conversions. View Denomination →

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    FeeMarket

    EIP-1559 gas pricing with base and priority fees. View FeeMarket →

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    Hardfork

    Ethereum network upgrades and protocol versions. View Hardfork →

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    Transaction

    Transaction creation and signing across networks. View Transaction →