# asChain

> **asChain**(`chain`): [`Chain`](/reference/filoz/synapse-core/chains/interfaces/chain/)

Defined in: [packages/synapse-core/src/chains.ts:339](https://github.com/FilOzone/synapse-sdk/blob/d75fb75a38297b6c379bc33142be552bb077741e/packages/synapse-core/src/chains.ts#L339)

Convert a viem chain to a filecoin chain.

## Parameters

| Parameter | Type | Description |
| ------ | ------ | ------ |
| `chain` | `Chain` | The viem chain. |

## Returns

[`Chain`](/reference/filoz/synapse-core/chains/interfaces/chain/)

The filecoin chain.

## Throws

Errors [asChain.ErrorType](/reference/filoz/synapse-core/chains/namespaces/aschain/type-aliases/errortype/)