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

> @extendable function priority_ check(tx_ body: gtx_ transaction_ body, tx_ size: integer, tx_ enter_ timestamp: integer, current_ timestamp: integer): prio

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

FUNCTION

# priority\_check

```signature
@extendable function priority_check(tx_body: gtx_transaction_body, tx_size: integer, tx_enter_timestamp: integer, current_timestamp: integer): priority_state_v1?
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/prioritization/module.rell#lines-68)

Extendable function that allows to define custom prioritization strategies.
If unimplemented, it will return `no_op_priority_state()`, which means everything will
have a priority of zero.

If any extension of this function throws, the transaction will be rejected.

**Parameters**

* **tx\_body** — the transaction
* **tx\_size** — size of the transaction in bytes
* **tx\_enter\_timestamp** — when the transaction entered the queue
* **current\_timestamp** — the current timestamp

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