Hangzhou (PtHangzHo)

The Hangzhou proposal features several major improvements to the protocol, as well as numerous minor improvements. Below, we present some of the most interesting and important changes:


Timelock encryption makes it possible for smart contract authors to include strong countermeasures against Block Producer Extractable Value (referred to as “MEV” on proof-of-work chains).


Views are a new kind of entrypoints for smart contracts, which make internal state information more easily accessible to other smart contracts.


Caching provides faster access to regularly accessed data and lowers the associated gas cost. It does so by splitting state storage between a “hot” storage, kept in RAM, and a “cold” storage, kept on disk. Caching directly increases the throughput of Tezos and can be built upon to further improve the performance of various parts of the protocol.

Global Table of Constants

The global table of constants can be used by smart contract developers to register Michelson expressions as “constants” and reference them in contracts. This allows developers to create larger and more complex contracts than they otherwise could. It will also serve as the foundation for smart contracts libraries in Tezos.

Context Flattening

Context flattening is a rewriting of the protocol’s database internals. It optimizes storage use, and will also enable future optimisations in order to speed up the processing of blocks and operations.

Liquidity baking

Hangzhou includes a small increase to the liquidity baking sunset level. Without this, the subsidy would halt during the lifespan of this protocol.

We invite you to look at the changelog for a full description of the contents of the proposal.

Proposal archive


Has there been absolutely no discussion on Agora for this proposal? That seems a bit odd.

There has also been a critical bug found.

There are two recommended paths of action. Vote NO and patch or let the vote ride out and use the User Activated Protocol Override mechanism

Is anyone else leaning towards voting ‘No’ to avoid the mess last time we needed all bakers to simultaneously upgrade?

We are far enough in the process to where I say we vote “yes” and go for the simultaneous upgrade.

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Congrats on the approval!

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