你可以查阅 chainlist.org 上现有的 EVM Chain ID，确保你选择的 ID 尚未被使用。

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双重 Chain ID 体系

Cosmos EVM 需要 两个完全独立的 Chain ID，以同时与 Cosmos SDK 生态和 Ethereum 生态保持完整兼容性。

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1. Cosmos Chain ID（字符串）

Cosmos Chain ID 是一个字符串标识符，用于：
  • CometBFT 共识引擎
  • IBC（跨链通信）协议
  • 原生 Cosmos SDK 交易
  • 链升级与治理
格式：任意字符串（推荐格式："mychain-1"、"testnet-2"） 示例： 
// In genesis.json
{
  "chain_id": "mychain-1"
}

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2. EVM Chain ID（整数）

EVM Chain ID 是一个整数，用于：
  • Ethereum 交易（EIP-155 重放保护）
  • MetaMask 和其他 Ethereum 钱包
  • 智能合约部署
  • EVM 工具链（Hardhat、Foundry 等）
格式：任意唯一正整数（请检查 chainlist.org） 示例： 
# In app.toml
[evm]
chain-id = 262144

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配置

在搭建你的链时，必须同时配置这两个 Chain ID：

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在应用代码中

// app/app.go
const (
    CosmosChainID = "cosmosevm-1"  // String for Cosmos/IBC
    EVMChainID    = 9000           // Integer for EVM/Ethereum
)

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在 Genesis 配置中

Cosmos Chain ID 在 genesis.json 中设置： 
{
  "chain_id": "cosmosevm-1",
  // ... other genesis parameters
}
EVM Chain ID 在 EVM 模块参数中配置： 
// During chain initialization
evmtypes.DefaultChainConfig(9000)  // Your EVM Chain ID

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重要注意事项

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EVM Chain ID 选择指南

选择你的 EVM Chain ID 时：
  1. 检查可用性：确认你选择的 ID 尚未在 chainlist.org 上被使用
  2. 避免冲突：不要使用知名的 Chain ID（例如 Ethereum 主网的 1、Polygon 的 137 等）
  3. 选择任意可用整数：没有强制的取值范围或格式，只需选择一个未被使用的整数即可

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链升级

与传统 Cosmos 链会在升级时变更其 Chain ID（例如从 cosmoshub-4 变为 cosmoshub-5）不同，EVM Chain ID 在升级过程中必须始终保持 不变，以维持与已部署智能合约和现有钱包的兼容性。
只有在需要进行破坏共识兼容性的变更时，Cosmos Chain ID 才可能在链升级期间发生变化。EVM Chain ID 一旦设定，就不应再更改。

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故障排查

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常见问题

  1. “Chain ID 不匹配”错误
    • 原因：在需要 EVM Chain ID 的地方使用了 Cosmos Chain ID（或反之）
    • 解决方案：确保在每个上下文中使用正确类型的 Chain ID
  2. MetaMask 连接失败
    • 原因：钱包配置中的 EVM Chain ID 不正确
    • 解决方案：使用整数类型的 EVM Chain ID，而不是字符串类型的 Cosmos Chain ID
  3. IBC 转账失败
    • 原因：在 IBC 操作中使用了 EVM Chain ID
    • 解决方案：IBC 始终使用 Cosmos Chain ID（字符串格式）
  4. 智能合约部署问题
    • 原因：EIP-155 重放保护使用了错误的 Chain ID
    • 解决方案：确保你的 EVM Chain ID 与链上的配置一致

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验证命令

要验证你的 Chain ID 是否已正确配置： 
# Check Cosmos Chain ID
curl -s http://localhost:26657/status | jq '.result.node_info.network'

# Check EVM Chain ID
curl -X POST -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' \
  http://localhost:8545 | jq '.result'
You can look up existing EVM Chain IDs by referring to chainlist.org to ensure your chosen ID is not already in use.

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Dual Chain ID System

Cosmos EVM requires two completely independent chain IDs to maintain full compatibility with both the Cosmos SDK and Ethereum ecosystems.

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1. Cosmos Chain ID (String)

The Cosmos Chain ID is a string identifier used by:
  • CometBFT consensus engine
  • IBC (Inter-Blockchain Communication) protocol
  • Native Cosmos SDK transactions
  • Chain upgrades and governance
Format: Any string (recommended format: "mychain-1", "testnet-2") Example: 
// In genesis.json
{
  "chain_id": "mychain-1"
}

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2. EVM Chain ID (Integer)

The EVM Chain ID is an integer used by:
  • Ethereum transactions (EIP-155 replay protection)
  • MetaMask and other Ethereum wallets
  • Smart contract deployments
  • EVM tooling (Hardhat, Foundry, etc.)
Format: Any unique positive integer (check chainlist.org) Example: 
# In app.toml
[evm]
chain-id = 262144

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Configuration

Both chain IDs must be configured when setting up your chain:

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In Your Application Code

// app/app.go
const (
    CosmosChainID = "cosmosevm-1"  // String for Cosmos/IBC
    EVMChainID    = 9000           // Integer for EVM/Ethereum
)

​
In Genesis Configuration

The Cosmos Chain ID is set in genesis.json: 
{
  "chain_id": "cosmosevm-1",
  // ... other genesis parameters
}
The EVM Chain ID is configured in the EVM module parameters: 
// During chain initialization
evmtypes.DefaultChainConfig(9000)  // Your EVM Chain ID

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Important Considerations

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EVM Chain ID Guidelines

When selecting your EVM Chain ID:
  1. Check availability: Verify your chosen ID is not already in use on chainlist.org
  2. Avoid conflicts: Don’t use well-known chain IDs (1 for Ethereum mainnet, 137 for Polygon, etc.)
  3. Choose any available integer: There are no required ranges or formats - simply pick any integer not in use

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Chain Upgrades

Unlike traditional Cosmos chains that change their chain ID during upgrades (e.g., cosmoshub-4 to cosmoshub-5), the EVM Chain ID must remain constant across upgrades to maintain compatibility with deployed smart contracts and existing wallets.
Only the Cosmos Chain ID may change during chain upgrades if needed for consensus-breaking changes. The EVM Chain ID should never change once set.

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Troubleshooting

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Common Issues

  1. “Chain ID mismatch” errors
    • Cause: Using Cosmos Chain ID where EVM Chain ID is expected (or vice versa)
    • Solution: Ensure you’re using the correct type of chain ID for each context
  2. MetaMask connection failures
    • Cause: Incorrect EVM Chain ID in wallet configuration
    • Solution: Use the integer EVM Chain ID, not the string Cosmos Chain ID
  3. IBC transfer failures
    • Cause: Using EVM Chain ID for IBC operations
    • Solution: IBC always uses the Cosmos Chain ID (string format)
  4. Smart contract deployment issues
    • Cause: EIP-155 replay protection using wrong chain ID
    • Solution: Ensure your EVM Chain ID matches what’s configured in the chain

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Verification Commands

To verify your chain IDs are correctly configured: 
# Check Cosmos Chain ID
curl -s http://localhost:26657/status | jq '.result.node_info.network'

# Check EVM Chain ID
curl -X POST -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}' \
  http://localhost:8545 | jq '.result'