Cosmex Pay – L2 Hydra-like payment system

[GENERAL] Name and surname of main applicant

[GENERAL] Are you delivering this project as an individual or as an entity (whether formally incorporated or not)

[GENERAL] Please specify how many months you expect your project to last (from 2-12 months)

[GENERAL] Please indicate if your proposal has been auto-translated into English from another language

[GENERAL] Summarize your solution to the problem (200-character limit including spaces)

Extend Cosmex L2 Exchange to support fast, secure and asynchronous off-chain payments on Cardano using Hydra-like state channels and ZK rollups.

[GENERAL] Does your project have any dependencies on other organizations, technical or otherwise?

[GENERAL] If YES, please describe what the dependency is and why you believe it is essential for your project’s delivery. If NO, please write “No dependencies.”

No dependencies.

[GENERAL] Will your project’s output/s be fully open source?

[GENERAL] Please provide here more information on the open source status of your project outputs

Smart contracts will be open sourced under Apache 2 license.

[SOLUTION] Please describe your proposed solution

Cosmex Exchange is building an L2 order book exchange that uses state channels for trading.

The same mechanism can be extended for fast off-chain payments.

With additional research it's possible to leverage new Plutus V3 builtins for Zero Knowledge rollups instead of state channel updates.

Our solution will provide a sequencer that will allow near-instant payments of Ada and CNTs between Cosmex Pay users.

Our design allows asynchronous interactions, meaning that a receiver doesn't have to be online to receive the payment, and clients can go on/off line whenever they want.

[IMPACT] Please define the positive impact your project will have on the wider Cardano community

This will be the first L2 off-chain near-instant payment system on Cardano.

Looks quite impactful.

[CAPABILITY & FEASIBILITY] What is your capability to deliver your project with high levels of trust and accountability? How do you intend to validate if your approach is feasible?

I’m a former compiler engineer at IOG, I worked on Marlowe DSL (https://marlowe.iohk.io).

I'm the author of Scalus – DApp development platform on Cardano

I'm the author and designer of Cosmex L2 Exchange

[PROJECT MILESTONES] What are the key milestones you need to achieve in order to complete your project successfully?

Cosmex Pay Litepaper & Whitepaper.

Extend Cosmex smart contracts to support payments.

Extend Cosmex API to support payments.

Research and development of leveraging Zero Knowledge Rollups for account balances updates.

Test the Cosmex Pay proof of concept on Testnet. Write documentation.

Demo the payment system on Testnet. Produce final report.

[RESOURCES] Who is in the project team and what are their roles?

The main proposer, Alexander Nemish will be actively working on the proposal.

I’m a former compiler engineer at IOG, I worked on Marlowe DSL (https://marlowe.iohk.io).

I’m a senior Scala engineer with more than 10 years of Scala development experience with companies like UBS and Deutsche Bank.

I'm the author and designer of Cosmex L2 Exchange

I'm the author of Scalus – DApp development platform on Cardano

Ruslan Shevchenko rssh – PhD in CS, prominent Scala engineer, compilers engineer and system architect.

[BUDGET & COSTS] Please provide a cost breakdown of the proposed work and resources

We estimated 3 months of research and development

3 month x 160h x $75 = 36000 / 0.30 = 120,000 ADA

[VALUE FOR MONEY] How does the cost of the project represent value for money for the Cardano ecosystem?

We'll have a L2 asynchronous off-chain near-instant payments PoC on Cardano for 100k ADA.

What's not to like?