Protocol Alpha

This page documents the changes brought by protocol Alpha with respect to Paris (see Protocol naming).

For changes brought by Paris with respect to Oxford, see Protocol Paris.

The code can be found in directory src/proto_alpha of the master branch of Octez.

Environment Version

This protocol requires a different protocol environment version than Paris. It requires protocol environment V13, compared to V12 for Paris.

  • Removed the 4th version of the WASM PVM, added the 5th version of the WASM PVM. (MR !12999)

Smart Rollups

  • Michelson values of type contract _ are now allowed in messages exchanged between smart contracts and smart rollups. In particular, it is now possible for smart rollups to use typed callbacks in outbox messages. (MR !11130)

  • Bumped WASM PVM to V5. (MR !12999)

  • Reworked constants migration to preserve the various period duration instead of indiscriminately imposing them (e.g., imposing 2 weeks for the challenge window or 15 minutes for the commitment period). (MR !13821)

Operation receipts

  • To better differentiate Deposits coming from ‘rewards from bakers own stakes’ from ‘the edge bakers may take from their stakers rewards’, the balance updates field has been specialized. The field {“staker”:{“baker”: <delegate_pkh>}} is now split into {“staker”:{“baker_own_stake”: <delegate_pkh>}} and {“staker”:{“baker_edge”: <delegate_pkh>}}. (MR !12258)


  • The validate.operation.inconsistent_sources and validate.operation.inconsistent_counters errors have been expanded with information on the problematic sources and counters. The error messages have been updated accordingly, but the error IDs remain unchanged. (MR !13138)

  • The message of the validate.operation.incorrect_reveal_position error has been updated to specify that the incorrectly placed revelation concerns the fee payer. (MR !13290)

8s Blocks Time (MR !)

Blocks time have been reduced from 10 seconds to 8 seconds. That is, a block can be produced with a delay of 8 seconds with respect to the previous block, if both blocks have round 0. This change comes with updating many related protocol parameters in order to match the reduced blocks time. In particular, the following quantities are kept the same:

  • the minimal time period of a cycle (namely, 2 days, 20 hours, and 16 minutes),

  • the length of the nonce revelation period (namely, around 2 hours and 8 minutes)

  • the number of nonce commitments per cycle (namely, 128),

  • the number of stake snapshots per cycle (namely, 16),

  • the maximum rewards per minute (namely 80 tez), and therefore roughly the same issuance,

  • the minimal “time to live” of an operation (namely, 1 hour),

  • the block gas limit per minute (namely, 10400000 gas),

  • the ratio between the liquidity baking subsidy and the maximum rewards per block (namely, 1/16).

Changes to protocol parameters

Parameter (unit)

Old (Paris) value

New value

minimal_block_delay (seconds)



delay_increment_per_round (seconds)



blocks_per_cycle (blocks)



blocks_per_commitment (blocks)



nonce_revelation_threshold (blocks)



max_operations_time_to_live (blocks)



hard_gas_limit_per_block (gas unit)