Please describe your proposed solution

Cirrus: A mobile/web PWA app that brings Cardano Lightning to the everyday user.

Cirrus combines secure instant payments and invoicing in one QR-based experience. Users can create direct payment channels to merchants or connect through a payment hub, enhancing transaction flexibility.

Cirrus's focus is to be easy to use by normal users but without compromising: your keys are yours; your channels are no different to any other channel on the CL network.

A light node works in contexts with limited resources and network access on devices that aren't always on-line, like a mobile. Connect to the network with sensible plug-and-play defaults, or role-your-own infra or a third party provider and Mithril for security.

Initially released as a PWA, Cirrus will be accessible via any browser and installable across multiple platforms, with plans to evolve into a native app for even broader reach.

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

Cirrus will significantly enhance Cardano's real-world applications by introducing fast, accessible, and secure mobile payments to the ecosystem. To achieve widespread adoption Cardano needs solutions that bridge the gap between digital and physical transactions.

Key Benefits

• Bringing Cardano to Real-World Finance: By providing a frictionless mobile app for instant payments, Cirrus enables Cardano users to make crypto transactions at physical locations, creating a foundation for “banking the unbanked.”

• Expansion to Online Retail: With mobile QR code scanning, Cirrus also extends Cardano’s reach to online retail, allowing payments even through digital displays, broadening the scope for e-commerce applications.

• User-Friendly Channel and Invoice Management: Cirrus simplifies complex tasks like channel creation and management, QR-based invoicing, and confirmations, making it an ideal tool for businesses and individuals seeking streamlined payment options on Cardano.

In Numbers

• Installations & Channel Setups: Measuring user adoption through app installations and the number of channels created.

• Transaction Volume: Tracking the value transacted across channels through Cirrus, gauging real-world utility and adoption rates.

• User Engagement and Retention: Monitoring metrics like daily active users (DAU) and repeat transactions to assess user satisfaction and retention.

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?

Capability

We are experienced team of Cardano developers (please check team information for more details).

We are are already working on the concept phase proposal for Cardano Lightning. This MVP proposal is a natural continuation of the above concept phase which will turn part of the design into the code.

We were experimenting with L2's on our own before as well:

• Dominic Algernon Wallis already prototyped in Aiken subbit.xyz which is related to this design phase but an independent micropayments proposal.

• Tomasz Rybarczyk is a core maintainer of Marlowe and a CIP contributor. Designed a micropayments capability in the context of Marlowe - the implementation is in the Marlowe Roadmap.

Development process will be public and open-source

Both the output and the development process will be public and open-source. This approach provides an easy way for the Catalyst team and the Cardano community to evaluate the progress at each step of the process.

We will form a working group around the idea and facilitate the discussion so everything will be transparent and easy to track on our pages: <https://github.com/cardano-lightning> and https://cardano-lightning.org

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

Milestone 1: Design

a. Milestone Outputs:

• Feature Requirements Outline: Descriptions of each feature, detailing required functionality and how users will interact with it (e.g., QR code scanning, channel state management).
• User Flow Documentation: Clear, concise user flows for core functions, such as setting up a channel, making a payment, generating invoices, and backing up data.
• Wireframes: Layout, key elements, and interactions for each feature (channel management, payments, key management, etc.).

b. Acceptance Criteria

• Documented requirements for each feature, outlining core functionality and user interactions.
• Documented user flows for key actions, showing step-by-step paths for each feature (in visual or non visual form).
• Wireframes

c. Evidence of Completion

• Post: Design walkthrough with an overview of core UX/UI decisions.
• Documentation and implementation available under project GitHub organization: <https://github.com/cardano-lightning>

*Posts are blog posts that are accessible either at the public github and the https://cardano-lightning.org website.

Milestone 2: Development Foundations

a. Milestone Outputs:

• Repository setup with stack choices.
• Initial “end-to-end” (e2e) tests, ensuring the initial setup and build produce installable artifacts.
• HTTP server serving PWA artifacts with SSL.

b. Acceptance Criteria:

• Public GitHub repo with stack selection, development setup, and a basic CI/CD pipeline.
• Documentation explaining stack choices and basic usage of the e2e tests.
• PWA app available online for testing and installation.

c. Evidence of Completion:

• Post: Design walkthrough with an overview of core UX/UI decisions.
• Initial GitHub repo with readme and setup instructions under CL organization: <https://github.com/cardano-lightning>.
• PWAs page available online for testing and installation.

Milestone 3: Key Management

a. Milestone Outputs:

• Key management functionality, including mnemonic generation, key derivation.
• Backup abstraction layer with encryption.

b. Acceptance Criteria:

• Key management functionality accessible and working in the app, with passphrase protection.
• Backup system in place, allowing for local storage of the data.

c. Evidence of Completion:

• Code available under the GitHub organization: <https://github.com/cardano-lightning>.
• New PWAs version available online for testing and installation.

Milestone 4: L1 Abstraction and Network Providers

a. Milestone Outputs:

• Abstraction layer for Level 1 (L1) blockchain interaction, allowing for flexible provider integrations.
• Basic status page to display L1 connection health (e.g., last connection status, current L1 provider).
• Implementation of the provider layer with 2 providers (eg Blockfrost).
• Experimental Mithril integration, subject to maturity.

b. Acceptance Criteria:

• Functional status page showing real-time L1 connection information.
• App capable of switching between network providers.
• App possibly able to use Mithril as L1 state verifier.

c. Evidence of Completion:

• Post: Explanation of the L1 abstraction and demo of the status page.
• New PWAs version available online for testing and installation.
• GitHub code updates showcasing the L1 interface and provider options.

Milestone 5: Channel Management and Peer-to-Peer (P2P) Payments

a. Milestone Outputs:

• Implementation of channel management, including opening, charging, and closing channels.
• Invoice QR code generation and scanning module.
• Routing options handling with direct channel setup or gateway detection/suggestions.

b. Acceptance Criteria:

• App version with features for creating and managing channels.
• Demonstration of a P2P payment workflow from invoice to confirmation.

c. Evidence of Completion:

• Post: Update with screenshots and explanations of the channel management functionality.
• PWAs available for testing and installation.
• Code available under project github organization: <https://github.com/cardano-lightning/>

Final Milestone: Close-out

a. Milestone Outputs:

• Final close-out report
• Final closeout video

b. Acceptance Criteria:

• Final closeout report is publicly available
• Final closeout video is publicly available

c. Evidence of Completion:

• Link to final closeout report
• Link to final closeout video

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

Tomasz Rybarczyk

• Professional experience:
• Nearly 20 years of coding and software design.
• Tons of open source.
• Cardano experience: ~3 years
• Member of Marlowe Team
• Profiles:
• Github Profile
• LinkedIn Profile

Dominic Algernon Wallis

• Professional experience:
• Phd in geometric topology. Former Data scientist/ ML eng.
• 10 years in software development.
• Cardano experience: ~3 years
• Runs artisan dapp dev house, Kompact.io
• Profiles:
• Github Profile
• LinkedIn Profile

Nicolas Henin (Consultant/Reviewer)

• Professional experience:
• 15 years in software development.
• North American Start-ups operating in Health/Wearable, Ad and Fin Tech industry.
• Cardano experience: More than 3 years
• Delivered on Cardano Mainnet: ICO Mechanism, an audited Smart Contract for World Mobile
• Member of Marlowe Team
• Profiles:
• Github Profile
• LinkedIn Profile
• Core Maintainer of Marlowe

Please provide a cost breakdown of the proposed work and resources

M1: 8 days

M2: 4 days

M3: 15 days

M4: 15 days

M5: 25 days

M6: 3 days

Contingency: 5 days

-------------

Total: 75 days

Cost per day: 1875₳ (3.33 Ada / $) ~ 570$

Total: 75 * 1875₳ = 150000₳

No dependencies

How does the cost of the project represent value for money for the Cardano ecosystem?

Our experienced team of Cardano developers is well-prepared to maximize impact through this MVP phase, building on the foundational concept work already underway for the Cardano Lightning Network. By investing in this MVP, Cardano will gain a functional, user-friendly app that extends the ecosystem into fast, accessible payments, opening up real-world applications and commercial use cases.

Our costings are based on prevailing European rates for researchers and developers, applied consistently across the team. With decades of collective experience, we bring a rare combination of technical and domain expertise, enabling us to deliver on complex blockchain integrations without delays for onboarding or learning curves. By building on our previous work and focusing on reusable, scalable components, this proposal will deliver significant value to the Cardano ecosystem efficiently and cost-effectively.