# isEvmKeyStore · FT4 TypeScript client · Chromia Docs (concept)

> isEvmKeyStore(keyStore: Signer ): keyStore is EvmKeyStore Type assertion function that checks if the specified signer is an EvmKeyStore Parameters keyStore

Source: https://docs.chromia.com/pages/ft4-ts-client/functions/authentication.isEvmKeyStore/

Function

# isEvmKeyStore

* ```signature
  isEvmKeyStore(keyStore: Signer): keyStore is EvmKeyStore
  ```

  Type assertion function that checks if the specified signer is an `EvmKeyStore`

  #### Parameters

  + keyStore: [Signer](https://docs.chromia.com/pages/ft4-ts-client/types/authentication.Signer/)

    the signer to check

  #### Returns keyStore is [EvmKeyStore](https://docs.chromia.com/pages/ft4-ts-client/interfaces/authentication.EvmKeyStore/)

  true if the specified signer was an `EvmKeyStore`. Else false.

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-ts-client/functions/authentication.isEvmKeyStore.html)Generated API reference, mirrored from the live docs