# is_blockchain · FT4 Rell API · Chromia Docs (concept)

> function is_ blockchain(account_ id: byte_ array): boolean Whether a certain account is a blockchain account Parameters account_id — the account to check

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.core.crosschain/is_blockchain/

FUNCTION

# is\_blockchain

```signature
function is_blockchain(account_id: byte_array): boolean
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/crosschain/blockchain.rell#lines-54)

Whether a certain account is a blockchain account

**Parameters**

* **account\_id** — the account to check

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-rell/-f-t4%20-library/lib.ft4.core.crosschain/is_blockchain.html)Generated API reference, mirrored from the live docs