Block binary format

Learn more about block.

Blocks are stored on the blockchain in a binary format (byte representation). Node extensions such as gRPC server can work directly with data in binary format.

Version 5

Binary format of block version 5 is defined in block.proto protobuf scheme. For more information about protobuf see Protocol Buffers Developer Guide.

Version 5 is enabled by feature #15 “Ride V4, VRF, Protobuf, Failed transactions”.

message Block {
    message Header {
        int32 chain_id = 1;
        bytes reference = 2;
        int64 base_target = 3;
        bytes generation_signature = 4;
        repeated uint32 feature_votes = 5;
        int64 timestamp = 6;
        int32 version = 7;
        bytes generator = 8;
        int64 reward_vote = 9;
        bytes transactions_root = 10;
    }
 
    Header header = 1;
    bytes signature = 2;
    repeated SignedTransaction transactions = 3;
}

Field	Description
chain_id	Chain ID
reference	• For the first block of version 5, that is, at the height of activation of feature #15 “Ride V4, VRF, Protobuf, Failed transactions”: signature of the previous block. • For the next blocks: BLAKE2b-256 hash of the previous block header
base_target	Base target: a variable that is used in the block generation algorithm
generation_signature	Generation signature: a variable that is used in the block generation algorithm (64 bytes)
feature_votes	List of features for which the block generator votes. See the Features
timestamp	Block timestamp: Unix time in milliseconds
version	Block version: 5
generator	Block generator’s account public key (32 bytes)
reward_vote	Block generation reward for which the block generator votes. -1 means that block generator votes for the current reward size
transactions_root	Transactions Root Hash (32 bytes)
signature	Block header signature (64 bytes)
transactions	For each transaction: • Body bytes: up to 165,487 bytes • Proofs: up to 531 bytes. See the Transaction Binary Format article

Version 4

#	Field	Field type	Field size in bytes	Comments
1	Block version	Byte	1	The value must be 4
2	Block timestamp	Long	8	Unix time in milliseconds
3	Signature of the previous block	Array[Byte]	64
4	Base target	Long	8
5	Genaration signature	Array[Byte]	32
6	Number of transactions in the block	Integer	4
7.1	Transaction 1	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the 1st transaction in binary format
7.2	Transaction 2	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the 2nd transaction in binary format
...	...	...	...	...
7.[N]	Transaction N	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the Nth transaction in binary format
8	Number of features for which the block generator votes	4	Integer
9.1	Feature 1	2	Short
...	...	...	...	...
9.[M]	Feature M	2	Short
10	Block generation reward for which the block generator votes	8	Long	-1 means that block generator votes for the current reward size
11	Block generator’s account public key	32	Array[Byte]
12	Block signature	64	Array[Byte]

Version 3

#	Field	Field type	Field size in bytes	Comments
1	Block version	Byte	1	The value must be 3
2	Block timestamp	Long	8	Unix time in milliseconds
3	Signature of the previous block	Array[Byte]	64
4	Base target	Long	8
5	Generation signature	Array[Byte]	32
6	Number of transactions in the block	Integer	4
7.1	Transaction 1	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the 1st transaction in binary format
7.2	Transaction 2	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the 2nd transaction in binary format
...	...	...	...	...
7.[N]	Transaction N	Array[Byte]	Body bytes: up to 165,996 bytes Proofs: up to 531 bytes	Bytes of the Nth transaction in binary format
8	Block generator’s account public key	Array[Byte]	32
9	Block signature	Array[Byte]	64