Past Tezos Amendments

A list of past successful protocol upgrades and their features.

Athens (Pt24m4xiP)

Athens was the first proposed protocol amendment for Tezos. Two proposals - “Athens A” and “Athens B” were injected by the development team, Nomadic Labs in February 2019.

Of the two proposals, Athens A sought to increase the gas limit and reduce the roll size required to bake from 10,000 tez to 8,000 tez. Athens B sought to just increase the gas limit. Athens A was autonomously activated onto the protocol in May 2019.

For a full list of changes be sure to read the corresponding blog post from Nomadic Labs and reflection by Jacob Arluck.

Babylon (PsBABY5nk)

The Babylon proposal was injected in August 2019 with contributions by development teams Nomadic Labs, Cryptium Labs (Metastate), and Marigold.

Notable changes included a new consensus algorithm variant (Emmy+), addition of new Michelson features to aid smart contract developers, an account rehaul that enabled clearer distinction between tz and kt accounts, as well as refinements to the quorum formula and addition of a 5% proposed quorum threshold.

Babylon was autonomously activated onto the protocol in October 2019.

For a full list of changes be sure to read the corresponding blog posts from Nomadic Labs, and Cryptium Labs (Metastate).

Carthage (PtCarthav)

The Carthage proposal was injected in December 2019 with contributions by development teams Nomadic Labs and Cryptium Labs (Metastate).

Notable changes included increasing the gas limit per block and operation by 30%, improving the accuracy of the formula used for calculating baking and endorsing rewards, as well as several minor improvements to Michelson.

Carthage was autonomously activated onto the protocol in March 2020.

For a full list of changes be sure to read the corresponding changelog and blog posts from Nomadic Labs and Cryptium Labs (Metastate).

Delphi (PsDELPH1K)

The Delphi proposal was injected in September 2020 with contributions by development teams Nomadic Labs, Metastate, and Gabriel Alfour.

Notable changes included improving the performance of the Michelson interpreter, improving gas costs by adjusting the gas model, reducing storage costs by 4x, and various other small fixes.

Delphi was autonomously activated onto the protocol in November 2020.

For a full list of changes be sure to read the corresponding changelog and blog post from Nomadic Labs.

Edo (PtEdoTezd)

The Edo proposal was injected in November 2020 with contributions by Nomadic Labs, Metastate, and Gabriel Alfour.

Edo adds two major features for Tezos smart contracts

  • Sapling and BLS12-381 to enable privacy-preserving smart contracts

  • Tickets for native on-chain permissions and asset issuance

Among other features, Edo also updates the Tezos amendment process by lowering period length to 5 cycles and by adding a 5th Adoption Period. A full changelog is available here