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

> function require_ operation(gtx_ transaction: gtx_ transaction, op_ name: text, verify_ signers: boolean, require_ anchored_ proof: boolean, min_ timestamp

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.iccf/require_operation/

FUNCTION

# require\_operation

```signature
function require_operation(gtx_transaction: gtx_transaction, op_name: text, verify_signers: boolean, require_anchored_proof: boolean, min_timestamp: integer, max_timestamp: integer, valid_source_blockchain_rids: set<byte_array>?): gtx_operation
```

[Source](https://gitlab.com/chromaway/ft4-lib/src/development/rell/src/lib/iccf/module.rell#lines-98)

Requires the presented transaction to be proved and extracts the specified operation

**Parameters**

* **gtx\_transaction** — The transaction to verify
* **op\_name** — Name of the operation to extract
* **verify\_signers** — Whether or not the signers must match current transaction signatures
* **require\_anchored\_proof** — Whether or not we require inclusion of a proof that the block containing the transaction has been anchored in cluster anchoring chain
* **min\_timestamp** — Limit for how old the transaction is allowed to be, disabled if 0
* **max\_timestamp** — Limit for how new the transaction is allowed to be, disabled if 0
* **valid\_source\_blockchain\_rids** — Valid source blockchains for transaction

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