P2P message format¶

Block header (shell)¶

Name	Size	Contents
level	4 bytes	signed 32-bit integer
proto	1 byte	unsigned 8-bit integer
predecessor	32 bytes	bytes
timestamp	8 bytes	signed 64-bit integer
validation_pass	1 byte	unsigned 8-bit integer
operations_hash	32 bytes	bytes
# bytes in field “fitness”	4 bytes	unsigned 30-bit integer
fitness	Variable	sequence of $fitness.elem
context	32 bytes	bytes
protocol_data	Variable	bytes

fitness.elem¶

Name	Size	Contents
# bytes in next field	4 bytes	unsigned 30-bit integer
Unnamed field 0	Variable	bytes

Operation (shell)¶

Name	Size	Contents
branch	32 bytes	bytes
data	Variable	bytes

Block_header (alpha-specific)¶

Name	Size	Contents
priority	2 bytes	unsigned 16-bit integer
proof_of_work_nonce	8 bytes	bytes
? presence of field “seed_nonce_hash”	1 byte	boolean (0 for false, 255 for true)
seed_nonce_hash	32 bytes	bytes
signature	64 bytes	bytes

Operation (alpha-specific)¶

Name	Size	Contents
contents	Variable	sequence of $operation.alpha.contents
signature	64 bytes	bytes

X_0¶

Name	Size	Contents
entrypoint	Determined from data	$entrypoint
? presence of field “value”	1 byte	boolean (0 for false, 255 for true)
value	Determined from data	$fitness.elem

X_2¶

Name	Size	Contents
fee_gas	Determined from data	$N.t
? presence of field “reveal_public_key”	1 byte	boolean (0 for false, 255 for true)
reveal_public_key	Determined from data	$public_key

X_3¶

Name	Size	Contents
target	21 bytes	$public_key_hash
? presence of field “signature”	1 byte	boolean (0 for false, 255 for true)
signature	64 bytes	bytes

X_5¶

Name	Size	Contents
# bytes in next field	4 bytes	unsigned 30-bit integer
Unnamed field 0	Variable	sequence of signed 64-bit integer

Z.t¶

A variable length sequence of bytes, encoding a Zarith number. Each byte has a running unary size bit: the most significant bit of each byte tells is this is the last byte in the sequence (0) or if there is more to read (1). The second most significant bit of the first byte is reserved for the sign (positive if zero). Size and sign bits ignored, data is then the binary representation of the absolute value of the number in little endian order.

Name	Size	Contents
Z.t	Determined from data	bytes

X_6¶

Name	Size	Contents
# bytes in next field	4 bytes	unsigned 30-bit integer
Unnamed field 0	Variable	bytes

X_4¶

Name	Size	Contents
? presence of field “proof_of_work_nonce_size”	1 byte	boolean (0 for false, 255 for true)
proof_of_work_nonce_size	1 byte	unsigned 8-bit integer
? presence of field “nonce_length”	1 byte	boolean (0 for false, 255 for true)
nonce_length	1 byte	unsigned 8-bit integer
? presence of field “max_revelations_per_block”	1 byte	boolean (0 for false, 255 for true)
max_revelations_per_block	1 byte	unsigned 8-bit integer
? presence of field “max_operation_data_length”	1 byte	boolean (0 for false, 255 for true)
max_operation_data_length	4 bytes	signed 31-bit integer in the range -1073741824 to 1073741823
? presence of field “max_proposals_per_delegate”	1 byte	boolean (0 for false, 255 for true)
max_proposals_per_delegate	1 byte	unsigned 8-bit integer
? presence of field “preserved_cycles”	1 byte	boolean (0 for false, 255 for true)
preserved_cycles	1 byte	unsigned 8-bit integer
? presence of field “blocks_per_cycle”	1 byte	boolean (0 for false, 255 for true)
blocks_per_cycle	4 bytes	signed 32-bit integer
? presence of field “blocks_per_commitment”	1 byte	boolean (0 for false, 255 for true)
blocks_per_commitment	4 bytes	signed 32-bit integer
? presence of field “blocks_per_roll_snapshot”	1 byte	boolean (0 for false, 255 for true)
blocks_per_roll_snapshot	4 bytes	signed 32-bit integer
? presence of field “blocks_per_voting_period”	1 byte	boolean (0 for false, 255 for true)
blocks_per_voting_period	4 bytes	signed 32-bit integer
? presence of field “time_between_blocks”	1 byte	boolean (0 for false, 255 for true)
time_between_blocks	Determined from data	$X_5
? presence of field “endorsers_per_block”	1 byte	boolean (0 for false, 255 for true)
endorsers_per_block	2 bytes	unsigned 16-bit integer
? presence of field “hard_gas_limit_per_operation”	1 byte	boolean (0 for false, 255 for true)
hard_gas_limit_per_operation	Determined from data	$Z.t
? presence of field “hard_gas_limit_per_block”	1 byte	boolean (0 for false, 255 for true)
hard_gas_limit_per_block	Determined from data	$Z.t
? presence of field “proof_of_work_threshold”	1 byte	boolean (0 for false, 255 for true)
proof_of_work_threshold	8 bytes	signed 64-bit integer
? presence of field “tokens_per_roll”	1 byte	boolean (0 for false, 255 for true)
tokens_per_roll	Determined from data	$N.t
? presence of field “michelson_maximum_type_size”	1 byte	boolean (0 for false, 255 for true)
michelson_maximum_type_size	2 bytes	unsigned 16-bit integer
? presence of field “seed_nonce_revelation_tip”	1 byte	boolean (0 for false, 255 for true)
seed_nonce_revelation_tip	Determined from data	$N.t
? presence of field “origination_size”	1 byte	boolean (0 for false, 255 for true)
origination_size	4 bytes	signed 31-bit integer in the range -1073741824 to 1073741823
? presence of field “block_security_deposit”	1 byte	boolean (0 for false, 255 for true)
block_security_deposit	Determined from data	$N.t
? presence of field “endorsement_security_deposit”	1 byte	boolean (0 for false, 255 for true)
endorsement_security_deposit	Determined from data	$N.t
? presence of field “block_reward”	1 byte	boolean (0 for false, 255 for true)
block_reward	Determined from data	$N.t
? presence of field “endorsement_reward”	1 byte	boolean (0 for false, 255 for true)
endorsement_reward	Determined from data	$N.t
? presence of field “cost_per_byte”	1 byte	boolean (0 for false, 255 for true)
cost_per_byte	Determined from data	$N.t
? presence of field “hard_storage_limit_per_operation”	1 byte	boolean (0 for false, 255 for true)
hard_storage_limit_per_operation	Determined from data	$Z.t
? presence of field “hard_gas_limit_to_pay_fees”	1 byte	boolean (0 for false, 255 for true)
hard_gas_limit_to_pay_fees	Determined from data	$Z.t
? presence of field “protocol_revision”	1 byte	boolean (0 for false, 255 for true)
protocol_revision	4 bytes	signed 31-bit integer in the range -1073741824 to 1073741823
? presence of field “max_operation_ttl”	1 byte	boolean (0 for false, 255 for true)
max_operation_ttl	4 bytes	signed 31-bit integer in the range -1073741824 to 1073741823
? presence of field “initial_endorsers”	1 byte	boolean (0 for false, 255 for true)
initial_endorsers	4 bytes	signed 31-bit integer in the range -1073741824 to 1073741823
? presence of field “delay_per_missing_endorsement”	1 byte	boolean (0 for false, 255 for true)
delay_per_missing_endorsement	8 bytes	signed 64-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
protocol_actions	Variable	sequence of $X_6
? presence of field “allow_collect_call”	1 byte	boolean (0 for false, 255 for true)
allow_collect_call	1 byte	boolean (0 for false, 255 for true)

X_7 (Determined from data, 8-bit tag)¶

Dune_activate_protocol (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
level	4 bytes	signed 32-bit integer
? presence of field “protocol”	1 byte	boolean (0 for false, 255 for true)
protocol	32 bytes	bytes
? presence of field “protocol_parameters”	1 byte	boolean (0 for false, 255 for true)
protocol_parameters	Determined from data	$X_4

Dune_manage_accounts (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
bytes	Variable	bytes

Dune_manage_account (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
? presence of field “target”	1 byte	boolean (0 for false, 255 for true)
target	Determined from data	$X_3
# bytes in next field	4 bytes	unsigned 30-bit integer
options	Variable	bytes

Dune_clear_delegations (tag 3)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

scripted.opt_or_hash (Determined from data, 8-bit tag)¶

No_script (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

Script_hash (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
code_hash	32 bytes	bytes
# bytes in next field	4 bytes	unsigned 30-bit integer
storage	Variable	bytes

Script_code_hash (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
code	Variable	bytes
code_hash	32 bytes	bytes
# bytes in next field	4 bytes	unsigned 30-bit integer
storage	Variable	bytes

Full_script (tag 255)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
code	Variable	bytes
# bytes in next field	4 bytes	unsigned 30-bit integer
storage	Variable	bytes

contract_id (22 bytes, 8-bit tag)¶

Implicit (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Signature.Public_key_hash	21 bytes	$public_key_hash

Originated (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Contract_hash	20 bytes	bytes
padding	1 byte	padding

entrypoint (Determined from data, 8-bit tag)¶

default (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

root (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

do (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

set_delegate (tag 3)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

remove_delegate (tag 4)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Unnamed field 0	0 bytes	placeholder (not actually present in the encoding)

named (tag 255)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	1 byte	unsigned 8-bit integer
Unnamed field 0	Variable	bytes

X_8¶

Name	Size	Contents
entrypoint	Determined from data	$entrypoint
# bytes in next field	4 bytes	unsigned 30-bit integer
value	Variable	bytes

N.t¶

A variable length sequence of bytes, encoding a Zarith number. Each byte has a running unary size bit: the most significant bit of each byte tells is this is the last byte in the sequence (0) or if there is more to read (1). Size bits ignored, data is then the binary representation of the absolute value of the number in little endian order.

Name	Size	Contents
N.t	Determined from data	bytes

public_key (Determined from data, 8-bit tag)¶

Ed25519 (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Ed25519.Public_key	32 bytes	bytes

Secp256k1 (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Secp256k1.Public_key	33 bytes	bytes

P256 (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
P256.Public_key	33 bytes	bytes

public_key_hash (21 bytes, 8-bit tag)¶

Ed25519 (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Ed25519.Public_key_hash	20 bytes	bytes

Secp256k1 (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
Secp256k1.Public_key_hash	20 bytes	bytes

P256 (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
P256.Public_key_hash	20 bytes	bytes

fitness.elem¶

Name	Size	Contents
# bytes in next field	4 bytes	unsigned 30-bit integer
Unnamed field 0	Variable	bytes

block_header.alpha.full_header¶

Name	Size	Contents
level	4 bytes	signed 32-bit integer
proto	1 byte	unsigned 8-bit integer
predecessor	32 bytes	bytes
timestamp	8 bytes	signed 64-bit integer
validation_pass	1 byte	unsigned 8-bit integer
operations_hash	32 bytes	bytes
# bytes in field “fitness”	4 bytes	unsigned 30-bit integer
fitness	Variable	sequence of $fitness.elem
context	32 bytes	bytes
priority	2 bytes	unsigned 16-bit integer
proof_of_work_nonce	8 bytes	bytes
? presence of field “seed_nonce_hash”	1 byte	boolean (0 for false, 255 for true)
seed_nonce_hash	32 bytes	bytes
signature	64 bytes	bytes

inlined.endorsement.contents (5 bytes, 8-bit tag)¶

Endorsement (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
level	4 bytes	signed 32-bit integer

inlined.endorsement¶

Name	Size	Contents
branch	32 bytes	bytes
operations	5 bytes	$inlined.endorsement.contents
signature	Variable	bytes

operation.alpha.contents (Determined from data, 8-bit tag)¶

Endorsement (tag 0)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
level	4 bytes	signed 32-bit integer

Seed_nonce_revelation (tag 1)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
level	4 bytes	signed 32-bit integer
nonce	32 bytes	bytes

Double_endorsement_evidence (tag 2)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
op1	Variable	$inlined.endorsement
# bytes in next field	4 bytes	unsigned 30-bit integer
op2	Variable	$inlined.endorsement

Double_baking_evidence (tag 3)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
bh1	Determined from data	$block_header.alpha.full_header
# bytes in next field	4 bytes	unsigned 30-bit integer
bh2	Determined from data	$block_header.alpha.full_header

Activate_account (tag 4)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
pkh	20 bytes	bytes
secret	20 bytes	bytes

Proposals (tag 5)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
period	4 bytes	signed 32-bit integer
# bytes in next field	4 bytes	unsigned 30-bit integer
proposals	Variable	sequence of bytes

Ballot (tag 6)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
period	4 bytes	signed 32-bit integer
proposal	32 bytes	bytes
ballot	1 byte	signed 8-bit integer

Reveal (tag 107)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
public_key	Determined from data	$public_key

Transaction (tag 108)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
amount	Determined from data	$N.t
destination	22 bytes	$contract_id
? presence of field “parameters”	1 byte	boolean (0 for false, 255 for true)
parameters	Determined from data	$X_8

Origination (tag 109)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
balance	Determined from data	$N.t
? presence of field “delegate”	1 byte	boolean (0 for false, 255 for true)
delegate	21 bytes	$public_key_hash
script	Determined from data	$scripted.opt_or_hash

Delegation (tag 110)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
? presence of field “delegate”	1 byte	boolean (0 for false, 255 for true)
delegate	21 bytes	$public_key_hash

Dune_manager_operation (tag 201)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
# bytes in next field	4 bytes	unsigned 30-bit integer
Unnamed field 0	Determined from data	$X_7

Transaction (tag 203)¶

Name	Size	Contents
Tag	1 byte	unsigned 8-bit integer
source	21 bytes	$public_key_hash
fee	Determined from data	$N.t
counter	Determined from data	$N.t
gas_limit	Determined from data	$N.t
storage_limit	Determined from data	$N.t
amount	Determined from data	$N.t
destination	22 bytes	$contract_id
parameters	Determined from data	$X_0
? presence of field “collect_call”	1 byte	boolean (0 for false, 255 for true)
collect_call	Determined from data	$X_2