Format of Various Fields in Serialized Transaction

Version

Example: 01000000

Size: 4 bytes

Format: Little-Endian

Description: The version number for the transaction. Used to enable new features.

Input Count

Example: 02

Size: variable

Format: Compact Size

Description: Indicates the number of inputs.

Input(s)

TXID:

Example: b9a2c28ea00905a5d24a172598b9574fbd973fc085df49901208a358d29a233b

Size: 32 bytes

Format: Natural Byte Order

Description: The TXID of the transaction containing the output you want to spend.

VOUT:

Example: 00000000

Size: 4 bytes

Format: Little-Endian

Description: The index number of the output you want to spend.

ScriptSig Size:

Example: 17

Size: variable

Format: Compact Size

Description: The size in bytes of the upcoming ScriptSig.

ScriptSig:

Example: 16001415ff0337937ecadd10ce56ffdfd4674817613223

Size: variable

Format: Script

Description: The unlocking code for the output you want to spend.

Sequence:

Example: f0ffffff

Size: 4 bytes

Format: Little-Endian

Description: Set whether the transaction can be replaced or when it can be mined.

Output Count

Example: 02

Size: variable

Format: Compact Size

Description: Indicates the number of outputs.

Output(s)

Amount:

Example: 007daf0100000000

Size: 8 bytes

Format: Little-Endian

Description: The value of the output in satoshis.

ScriptPubKey Size:

Example: 19

Size: variable

Format: Compact Size

Description: The size in bytes of the upcoming ScriptPubKey.

ScriptPubKey:

Example: 76a91471a3d2f54b0917dc9d2c877b2861ac52967dec7f88ac

Size: variable

Format: Script

Description: The locking code for this output.

Witness

Stack Items:

Example: 02

Size: variable

Format: Compact Size

Description: The number of items to be pushed on to the stack as part of the unlocking code.

Field

Size:

Example: 47

Size: variable

Format: Compact Size

Description: The size of the upcoming stack item.

Item:

Example: 304…b01

Size: variable

Format: Bytes

Description: The data to be pushed on to the stack.

Locktime

Example: 00000000

Size: 4 bytes

Format: Little-Endian

Description: Set a time or height after which the transaction can be mined.

Note:

When any transaction is serialized these fields are added in the given sequence only.

When transactions are transmitted over the network or exchanged between applications, they are serialized. Serialization is most commonly used for encoding data structures for transmission over a network or for storage in a file. The serialization format of a transaction output is shown in Transaction output serialization. This article focuses on discussing steps to decode input data from a transaction.