Transaction Fields and Global Parameters

A PyTeal expression can be the value of a field of the current transaction or the value of a global parameter. Blow are the PyTeal expressions that refer to transaction fields:

Operator Type Notes
Txn.sender() TealType.bytes 32 byte address
Txn.fee() TealType.uint64 in microAlgos
Txn.first_valid() TealType.uint64 round number
Txn.first_valid_time() TealType.uint64 causes program to fail, reserved for future use
Txn.last_valid() TealType.uint64 round number
Txn.note() TealType.bytes  
Txn.lease() TealType.bytes  
Txn.receiver() TealType.bytes 32 byte address
Txn.amount() TealType.uint64 in microAlgos
Txn.close_remainder_to() TealType.bytes 32 byte address
Txn.vote_pk() TealType.bytes 32 byte address
Txn.selection_pk() TealType.bytes 32 byte address
Txn.vote_first() TealType.uint64  
Txn.vote_last() TealType.uint64  
Txn.vote_key_dilution() TealType.uint64  
Txn.type() TealType.bytes  
Txn.type_enum() TealType.uint64 see table below
Txn.xfer_asset() TealType.uint64 asset ID
Txn.asset_amount() TealType.uint64 value in Asset’s units
Txn.asset_sender() TealType.bytes 32 byte address, causes clawback of all value if sender is the Clawback
Txn.asset_receiver() TealType.bytes 32 byte address
Txn.asset_close_to() TealType.bytes 32 byte address
Txn.group_index() TealType.uint64 position of this transaction within a transaction group
Txn.tx_id() TealType.bytes the computed ID for this transaction, 32 bytes

Txn.type_enum() values:

Value Type String Description
Int(0) unkown unknown type, invalid
Int(1) pay payment
Int(2) keyreg key registration
Int(3) acfg asset config
Int(4) axfer asset transfer
Int(5) afrz asset freeze

PyTeal expressions that refer to global parameters:

Operator Type Notes
Global.min_txn_fee() TealType.uint64 in microAlgos
Global.min_balance() TealType.uint64 in mircoAlgos
Global.max_txn_life() TealType.uint64 number of rounds
Global.zero_address() TealType.bytes 32 byte address of all zero bytes
Global.group_size() TealType.uint64 number of txns in this atomic transaction group, At least 1