# (PtMumbaii)
**URL:** https://forum.tezosagora.org/t/ptmumbaii/4988
**Category:** Proposals
**Created:** [January 17, 2023, 4:34pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988 "2023-01-17T16:34:55Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@tezosagora](https://forum.tezosagora.org/u/tezosagora)
#### Post date: [January 17, 2023, 4:34pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/1 "2023-01-17T16:34:55Z")
_UPDATE: Mumbai has been approved by the community and will go live on mainnet at block 3,268,609, currently estimated to occur around March 29, 2:24:00 PM UTC._
_This is a joint post from Nomadic Labs, Marigold, TriliTech, Oxhead Alpha, Tarides, DaiLambda & Functori._
We’re happy to announce that Mumbai, our next Tezos protocol proposal, is ready. As usual, Mumbai’s ‘true’ name is its hash, which is `PtMumbaiiFFEGbew1rRjzSPyzRbA51Tm3RVZL5suHPxSZYDhCEc`.
The main features of this protocol upgrade proposal are:
- [Smart rollups are activated](https://research-development.nomadic-labs.com/mumbai-preview.html#smart-rollups-activated): Smart rollups are fully operational on Mainnet offering a powerful scaling solution. Anyone can deploy decentralized WebAssembly applications with dedicated computational and networking resources.
- [Epoxy makes its first appearance](https://research-development.nomadic-labs.com/mumbai-preview.html#epoxy-validity-rollups-on-mondaynet-testnet): Validity Rollups (aka ZK-rollups) arrive on the Mondaynet testnet. Epoxy allows for instant finality due to SNARK’s proof-of-validity.
- [Block time reduced to 15 seconds](https://research-development.nomadic-labs.com/mumbai-preview.html#pipelining-is-fully-deployed-giving-us-15-second-block-times): With improved pipelining fully deployed, block propagation times are significantly reduced – this allows for the minimal block time to be cut in half to 15 seconds!
- [Ticket transfers between accounts](https://research-development.nomadic-labs.com/mumbai-preview.html#other-improvements): In Mumbai, tickets can be [transferred between user accounts](https://gitlab.com/tezos/tezos/-/merge_requests/6108) (aka. implicit accounts) and not just to/from smart contracts and rollups.
- [RPCs for ticket balances](https://research-development.nomadic-labs.com/mumbai-preview.html#other-improvements): Two new RPC endpoints were added to improve the visibility of ticket ownership. /all\_ticket\_balances returns a complete list of tickets owned by a given contract. And /ticket\_balance returns the given-contract’s balance of the ticket with specified ticketer, content type, and content.
- [New Michelson operations](https://research-development.nomadic-labs.com/mumbai-preview.html#other-improvements): Michelson opcodes AND, OR, XOR, NOT, LSL and LSR were extended to support [logical operations on bytes](https://gitlab.com/tezos/tezos/-/merge_requests/6055), similar to those on nat. And an opcode was added to [convert between bytes and nat](https://gitlab.com/tezos/tezos/-/merge_requests/6681).
To learn more about Mumbai’s contents, see our [full preview post](https://research-development.nomadic-labs.com/mumbai-preview.html).
In addition to these exciting new features and steady progress, the Mumbai proposal disables [Transaction Optimistic Rollups](https://research-development.nomadic-labs.com/toru-introduction.html) (TORUs) on `Mainnet`. TORUs were the first optimistic rollup implementation on `Mainnet` enabled with [Jakarta](https://research-development.nomadic-labs.com/jakarta-is-live.html) mid 2022, and the first step of the scalability [roadmap presented](https://research-development.nomadic-labs.com/tezos-is-scaling.html) last March.
Transaction rollups were always intended to be an temporary solution, as clearly indicated by the sunset they were released with. Now that smart rollups are reaching Tezos `Mainnet`, it makes little sense to keep transaction rollups enabled, as this functionality can easily be implemented through Smart Rollups. It is important to understand that, if Mumbai is voted in by the community, the transaction rollup subsystem will be completely disabled as soon as the protocol becomes activate on `Mainnet`. This means tickets deposited on transaction rollups will be lost forever, and operators will not be able to reclaim their ꜩ 10,000 bond. Currently, no transaction rollups have been originated on `Mainnet`.
The [changelog](https://tezos.gitlab.io/protocols/016_mumbai.html) provides a detailed list of changes, and a general technical overview of Mumbai can be found in the protocol proposal’s [technical documentation](https://tezos.gitlab.io/mumbai/protocol.html).
Note that, if Mumbai is voted in by the community, upgrading to Octez v16.0 (or later) will be necessary for participating in consensus. A release candidate for Octez v16.0 will be published in the coming days, and a dedicated protocol test network `Mumbainet` is also scheduled to begin soon. More information about the test network will be available on [https://teztnets.xyz/](https://teztnets.xyz/).
## [Smart Rollups and Epoxy testers wanted](https://research-development.nomadic-labs.com/mumbai-announcement.html#smart-rollups-and-epoxy-testers-wanted)
First, Smart Rollups will be active on `Mumbainet` soon. Functioning rollups implemented in Rust are currently running on `Mondaynet`. We highly encourage ecosystem participants to experiment and build with these rollups. In roughly 2 months they are expected to activate on `Mainnet`, assuming Mumbai is voted in. Smart Rollups are instrumental in our efforts to reach [1 millon TPS](https://research-development.nomadic-labs.com/smart-rollups-are-coming.html).
Second, Epoxy - Tezos’ validity rollup (aka ZK-rollup) solution makes its way onto `Mondaynet`. It’s not, however, part of the Mumbai protocol upgrade, as more time needs to be spent on validation, testing, and integration with ecosystem tools before they can be activated on Mainnet. We ask ecosystem participants to start experimenting with Epoxy on `Mondaynet`.
Broad testing and feedback from the ecosystem is invaluable in our efforts to minimize the risk of undetected issues upon `Mainnet` activation.
Read more about Tezos testnets [here](https://teztnets.xyz/), and don’t hesitate to reach out in the [Tezos Developer Slack](https://tezos-dev.slack.com/) or in the [Tezos Discord](https://discord.com/invite/5v5QVKjvc2) if you need help getting started.
Anyone interested in getting started with building a smart rollup node can reach out to [contact@nomadic-labs.com](mailto:contact@nomadic-labs.com).
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### Author:  [@Britcoin](https://forum.tezosagora.org/u/Britcoin)
#### Post date: [January 24, 2023, 1:18pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/2 "2023-01-24T13:18:24Z")
> [@tezosagora](#):
>
> Second, Epoxy - Tezos’ validity rollup (aka ZK-rollup) solution makes its way onto `Mondaynet`. It’s not, however, part of the Mumbai protocol upgrade, as more time needs to be spent on validation, testing, and integration with ecosystem tools before they can be activated on Mainnet. We ask ecosystem participants to start experimenting with Epoxy on `Mondaynet`.
In the blogpost from 8 December:
When can we expect the blogpost about Epoxy? As there is still not much info and would like to read 🙂
Maybe @germanD - do you know?
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### Author:  [@germanD](https://forum.tezosagora.org/u/germanD)
#### Post date: [January 25, 2023, 9:07pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/3 "2023-01-25T21:07:39Z")
I cannot promise dates, but this is definitely in our pipeline.
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### Author:  [@Primate411](https://forum.tezosagora.org/u/Primate411)
#### Post date: [April 6, 2023, 9:00pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/4 "2023-04-06T21:00:41Z")
Mumbai2 has already been injected as is working as intended. Do not vote for Mumbai again during governance cycle #94.
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### Author:  [@Britcoin](https://forum.tezosagora.org/u/Britcoin)
#### Post date: [April 22, 2023, 12:17am UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/5 "2023-04-22T00:17:19Z")
> [@germanD](#):
>
> I cannot promise dates, but this is definitely in our pipeline.
The announcement for the blogpost was in December 2022 and we soon will have May 2023.. I guess the Expoxy blogpost is cancelled? @germanD
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### Author:  [@germanD](https://forum.tezosagora.org/u/germanD)
#### Post date: [May 5, 2023, 9:12pm UTC](https://forum.tezosagora.org/t/ptmumbaii/4988/6 "2023-05-05T21:12:21Z")
The article is finally out 👇
> **[On the future of validity rollups on Tezos](https://research-development.nomadic-labs.com/future-validity-rollups.html)**
>
> We are combining optimistic rollups and validity rollups in a single product.
I reckon the article explains partly the reason for the delay – the last two sections at least 🙂