# Chains

The root `sushi` entrypoint exposes a unified chain registry across supported environments.

```ts twoslash
import { ChainId, chains, getChainById, isChainId } from 'sushi'

const ethereum = getChainById(ChainId.ETHEREUM)

if (isChainId(1)) {
  const chain = getChainById(1)
  console.log(chain.name)
}

console.log(chains.length)
```

## Root chain exports

| Export | Purpose |
|---|---|
| `chains` | All known chains across EVM, SVM, MVM, and Stellar. |
| `ChainId` | Enum-like chain ID lookup by uppercase chain key. |
| `chainIds` | Array of known chain IDs. |
| `isChainId` | Type guard for unknown numbers. |
| `getChainById` | Get chain metadata by ID. |
| `isMainnetChainId` | Guard for mainnet chain IDs. |
| `isTestnetChainId` | Guard for testnet chain IDs. |
| `getChainByKey` | Get chain metadata by chain key. |

## Chain-specific registries

Use subpath exports when you only want one chain environment.

```ts
import { evmChains, EvmChainId } from 'sushi/evm'
import { stellarChains, StellarChainId } from 'sushi/stellar'
import { svmChains, SvmChainId } from 'sushi/svm'
import { mvmChains, MvmChainId } from 'sushi/mvm'
```

## Chain support is not feature support

A chain can be present in `chains` without supporting every Sushi feature. For EVM feature support, use the config exports from `sushi/evm`, such as API, V2, V3, subgraph, and contract support maps.