callDataField.md

Data Structure in UserOperation.calldata

Offset	Field	Block Size	Note
0	execFromEntryPoint() fs*	4
4	destination address	32	1st param
36	msg.value to send	32	2nd param
68	location of data of func	32	3rd param
100	number of element of bytes func	32	3rd param
132	fs* of target contract to call	4	target call func
136	target func parameter	N/A

* fs: function selector

execFromEntryPoint() requires three parameters:

• address dest: the target contract/ account address.
• uint256 value: value to be included in this call.
• bytes func: the data to be handled by target contract. Check how dynamic type is used in parameter.

Note: The parameters are padded to 32 bytes.

Example Case For ERC20 approve()

Offset	Field	Block Size	Note
0	execFromEntryPoint() fs*	4
4	destination address	32	1st param
36	msg.value to send	32	2nd param
68	location of data of func	32	3rd param
100	number of element of bytes func	32	3rd param
132	approve() function selector	4	target call func
136	spender address	32	1st param of approve
168	approve amount	32	2nd param of approve
200	padding	28	padding the last data section to 32 bytes