Protocol forks

The protocol forks the model executes, oldest to newest. Their singleton integer values are the activation order, so ordinary integer comparisons express every fork gate without an overloaded comparison or conversion. Pure data — no registers, no externs.

type Fork

Every supported protocol and schema fork, in activation order. This is the sole fork identity in the model: the decoded schema byte selects a ProtocolProfile, which stores one of these values. The bounded semantic type prevents values outside the supported fork sequence, while each named constant retains its precise singleton type for dependent profile typing.

type Fork = range(0, 16)

type frontier_fork_value

Singleton indices for the supported fork sequence. Keeping the numeric identities named lets dependent profile constraints refer to protocol forks without repeating their wire-order integers.

type frontier_fork_value : Int = 0

type homestead_fork_value

Homestead's position in the activation order.

type homestead_fork_value : Int = 1

type byzantium_fork_value

Byzantium's position in the activation order.

type byzantium_fork_value : Int = 2

type constantinople_fork_value

Constantinople's position in the activation order.

type constantinople_fork_value : Int = 3

type istanbul_fork_value

Istanbul's position in the activation order.

type istanbul_fork_value : Int = 4

type berlin_fork_value

Berlin's position in the activation order.

type berlin_fork_value : Int = 5

type london_fork_value

London's position in the activation order.

type london_fork_value : Int = 6

type arrow_glacier_fork_value

ArrowGlacier's position in the activation order.

type arrow_glacier_fork_value : Int = 7

type gray_glacier_fork_value

GrayGlacier's position in the activation order.

type gray_glacier_fork_value : Int = 8

type paris_fork_value

Paris's position in the activation order.

type paris_fork_value : Int = 9

type shanghai_fork_value

Shanghai's position in the activation order.

type shanghai_fork_value : Int = 10

type first_blob_fork_value

First fork at which blob gas is active. Kept as a type-level singleton so profile equations and the runtime Cancun value share one boundary.

type first_blob_fork_value : Int = 11

type prague_fork_value

Prague's position in the activation order.

type prague_fork_value : Int = 12

type osaka_fork_value

Osaka's position in the activation order.

type osaka_fork_value : Int = 13

type bpo1_fork_value

BPO1's position in the activation order.

type bpo1_fork_value : Int = 14

type bpo2_fork_value

BPO2's position in the activation order.

type bpo2_fork_value : Int = 15

type amsterdam_fork_value

Amsterdam's position in the activation order.

type amsterdam_fork_value : Int = 16

Constants

The runtime fork values, one per supported fork. Each constant carries its type-level index as a singleton type, so comparing two fork values compares their activation order.

Constants	Values	Character
Frontier … Shanghai	0 – 10	the pre-blob protocol and schema forks
Cancun	11	the first fork with an active blob schedule
Prague, Osaka	12, 13	blob-era execution forks
BPO1, BPO2	14, 15	blob-parameter-only schema forks
Amsterdam	16	the newest supported fork

let Frontier

Launch protocol.

let Frontier : int(frontier_fork_value) = sizeof(frontier_fork_value)

let Homestead

EIP-2 create rules, EIP-7 DELEGATECALL.

let Homestead : int(homestead_fork_value) = sizeof(homestead_fork_value)

let Byzantium

EIP-140 REVERT, EIP-211 returndata; precompiles 0x05-0x08.

let Byzantium : int(byzantium_fork_value) = sizeof(byzantium_fork_value)

let Constantinople

EIP-145 shifts, EIP-1014 CREATE2, EIP-1052 EXTCODEHASH.

let Constantinople : int(constantinople_fork_value) = sizeof(constantinople_fork_value)

let Istanbul

EIP-1344 CHAINID, EIP-2200 SSTORE metering.

let Istanbul : int(istanbul_fork_value) = sizeof(istanbul_fork_value)

let Berlin

EIP-2929/2930 access lists and warm/cold access costs.

let Berlin : int(berlin_fork_value) = sizeof(berlin_fork_value)

let London

EIP-1559 fee market and EIP-3529 refund reduction.

let London : int(london_fork_value) = sizeof(london_fork_value)

let ArrowGlacier

Difficulty-bomb-only schema fork; execution rules remain London.

let ArrowGlacier : int(arrow_glacier_fork_value) = sizeof(arrow_glacier_fork_value)

let GrayGlacier

Difficulty-bomb-only schema fork; execution rules remain London.

let GrayGlacier : int(gray_glacier_fork_value) = sizeof(gray_glacier_fork_value)

let Paris

EIP-4399 PREVRANDAO replaces DIFFICULTY.

let Paris : int(paris_fork_value) = sizeof(paris_fork_value)

let Shanghai

EIP-3651 warm coinbase, EIP-3855 PUSH0, EIP-3860 initcode.

let Shanghai : int(shanghai_fork_value) = sizeof(shanghai_fork_value)

let Cancun

EIP-1153/4844; precompiles 0x01-0x0a.

let Cancun : int(first_blob_fork_value) = sizeof(first_blob_fork_value)

let Prague

EIP-7623 calldata floor; BLS precompiles 0x0b-0x11.

let Prague : int(prague_fork_value) = sizeof(prague_fork_value)

let Osaka

EIP-7883 modexp gas, EIP-7825 cap; precompile 0x100.

let Osaka : int(osaka_fork_value) = sizeof(osaka_fork_value)

let BPO1

First blob-parameter-only fork; execution rules remain Osaka.

let BPO1 : int(bpo1_fork_value) = sizeof(bpo1_fork_value)

let BPO2

Second blob-parameter-only fork; execution rules remain Osaka.

let BPO2 : int(bpo2_fork_value) = sizeof(bpo2_fork_value)

let Amsterdam

EIP-7954 code/initcode size bump (65536/131072).

let Amsterdam : int(amsterdam_fork_value) = sizeof(amsterdam_fork_value)