VESPR: Any-Payment Mobile Deep Link and SDK 🌐 | Streamlining Cross-Application Requests

[GENERAL] Name and surname of main applicant

VESPR Team

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

Entity (Incorporated)

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

9

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

No

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

We will create an enhanced deep link standard that enables any browser, mobile app, game or physical store to communicate with Cardano wallets for seamless payment requests, and message signing.

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

No

[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?

Yes

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

The new deep linking standard will be done publicly with community collaboration as a Cardano Improvement Proposal (CIP).

The SDK code will be open-sourced on Github under MIT License.

[METADATA] Horizons

Developer Tools

[SOLUTION] Please describe your proposed solution

Our solution expands the current Cardano deep linking standard to allow seamless communication between external browsers, mobile apps, games and physical stores with Cardano wallets. Today, mobile dApp connectors only work in in-app browsers, limiting their use across platforms. Physical stores also lack a reliable method to request and track Cardano payments, which hinders adoption for real-world use.

Problem Solved:

We will create a universal deep link standard where wallets can receive a request URL and request ID, allowing any browser, app, games, or store to send payment requests, prove identity or verify ownership securely. This solution reduces friction and simplifies transactions across platforms.

Approach:

Our deep link standard will enable wallets to securely fetch transaction details through a URI scheme, providing a user-friendly way to handle purchases, payments, identity verification, message signing, and asset verification. This enhances cross-platform compatibility for wallets, dApps, games, and stores.

Engagement and Beneficiaries:

• Developers can easily integrate Cardano payments into their mobile and web dApps and apps.
• Users will enjoy more intuitive payment experiences across web, mobile, and physical stores.
• Businesses can use dynamic QR codes or deep linking to request and track Cardano payments in-store.

Impact:

We will track success through the number of integrations, transaction volume, and feedback from developers and users, demonstrating the real-world use of Cardano payments.

Unique Value:

This solution bridges the gap between dApps, mobile, browsers, and physical stores, making Cardano payment and verification requests frictionless and driving broader adoption in real-world commerce.

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

Our project will enhance the Cardano ecosystem by simplifying payment requests and transaction tracking across various platforms. By making these processes more accessible, we create a smoother user experience, enabling dApps, mobile apps, and physical stores to easily interact with Cardano wallets. This will increase the utility and adoption of ADA in everyday use cases, fostering a more vibrant and active community.

Positive Impact on the Cardano Community:

• Developers: Our SDK will reduce the technical complexity of integrating Cardano payments, allowing developers to focus on building innovative applications without needing deep expertise in blockchain. This opens the door for more diverse and creative dApps, encouraging growth in the Cardano development ecosystem.
• Businesses: By enabling physical stores and online merchants to handle Cardano payments more easily, our project will help increase real-world adoption of ADA as a payment method. Businesses can offer their customers secure, efficient payment options, expanding Cardano’s reach in commerce.
• End Users: Cardano holders will enjoy a more user-friendly payment experience, with the ability to seamlessly complete transactions and verify ownership in various contexts, whether online, in mobile apps, or in physical stores. This ease of use will encourage more frequent use of ADA for transactions, fostering wider adoption and engagement.

Sharing Outputs:

We will release the SDK as an open-source project, along with comprehensive documentation, and support materials to help developers and businesses integrate it into their services. By engaging with the Cardano community through forums, social media, and collaborative platforms, we’ll ensure that the SDK and deep link standard gain wide visibility and usage. The goal is to make Cardano payments easier and more intuitive for everyone, fostering long-term engagement and utility across the ecosystem.

[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?

Our team is well-positioned to deliver this project with trust and accountability, thanks to our experience as co-proposers of CIP-0099 (Proof of Onboarding), which uses a similar URI scheme for airdrops via QR codes. This standard was highly successful and widely used at recent Cardano events, showcasing our ability to implement similar solutions.

Capability & Expertise:

We have deep expertise in building Cardano-integrated SDKs and URI schemes, demonstrated by our successful work on CIP-0099 and other projects like the VESPR Wallet. Our previous open-source SDK developments, such as the Ledger Flutter SDK and Ledger Flutter Cardano Plugin, further highlight our ability to execute developer-friendly and reliable solutions.

Feasibility:

This project builds on our prior experience with URI schemes and is validated by the success of CIP-0099, proving the approach is practical and scalable. Our team’s familiarity with the technology ensures efficient delivery, and community feedback will guide the solution’s development.

Trust & Accountability:

We will maintain transparent fund management, with regular updates and open-source development on GitHub. Our track record shows we can manage funds responsibly, and all work will be visible to the community to ensure accountability.

In short, our success with CIP-0099 and other Cardano projects demonstrates we are capable of delivering this project reliably and transparently.

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

Research Stage and CIP Drafting

• Outputs: Conduct research and draft a Cardano Improvement Proposal (CIP) to formally define the enhanced deep linking standard and SDK. This includes documenting the technical specifications, use cases, and benefits of the solution.
• Acceptance Criteria: A PR containing completed CIP document, outlining the standard and technical details, published on GitHub for community review and feedback.
• Evidence: The PR containing the CIP markdown document is publicly available on GitHub, serving as the formal proposal and foundation for the project.

Prototype Development

• Outputs: Develop a working prototype of the enhanced deep link standard and the SDK. This will include basic functionality, such as transaction request handling and payment status tracking.
• Acceptance Criteria: A functional prototype capable of sending transaction requests to Cardano wallets, receiving responses, and tracking payment statuses.
• Evidence: Demonstration video or screenshots showing a successful payment request and response using the prototype.

API and SDK Finalization

• Outputs: Finalize the deep link API and SDK with complete documentation. The SDK should support various use cases such as in-app and in-store payments, and browser-to-wallet requests.
• Acceptance Criteria: A fully functional SDK with finalized API routes and a comprehensive set of documentation for developers.
• Evidence: SDK available on GitHub with full documentation and integration guides.

VESPR Wallet Integration

• Outputs: Add support for the new URI into VESPR wallet, allowing third party application to request message signing and/or payments.
• Acceptance Criteria: VESPR wallet integration is complete, with all deep link functionalities working seamlessly.
• Evidence: Video demonstration or screenshots of the VESPR wallet handling a payment request from a third party partner or test application.

Beta Release, Community Feedback, and Reporting

• Outputs: Publish a beta version of the VESPR wallet with the integrated deep link standard and SDK, and gather feedback from users and developers to refine the product. Additionally, prepare and submit the Catalyst closeout report and video summarizing the project’s achievements and future outlook.
• Acceptance Criteria: Beta release with active feedback collection from early users and developers. Completion and submission of the Catalyst closeout report and video.
• Evidence: Beta version available for download, feedback reports from testers, and the Catalyst closeout report and video published and submitted to the Catalyst platform.

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

Alex Dochioiu | CEO & Senior Software Architect

• LinkedIn: https://www.linkedin.com/in/alexandru-dochioiu

Alex, founder and senior software architect of VESPR Wallet, has over 10 years of experience developing safety-critical mobile applications for major financial institutions, including American Express and Virgin Money. His extensive background ensures that VESPR adheres to industry best practices and maintains the highest technical standards. Alex brings a wealth of knowledge in handling complex, mission-critical systems, ensuring smooth execution of the technical aspects of the project.

In addition to leading VESPR, Alex is a member of Cardano's Product Committee and the Cardano Blockchain Infrastructure Alliance, where he contributes to shaping the long-term vision and strategy for the Cardano blockchain. His involvement in the committee allows him to align VESPR’s development with the broader goals of the Cardano ecosystem, ensuring that both the project and the platform evolve in tandem.

Vlad Stan | Engineering Manager and Senior Software Engineer

• LinkedIn: https://www.linkedin.com/in/stanvladut/

Vlad oversees the entire software development process, managing the project's lifecycle, coordinating resource allocation, and ensuring rigorous quality assurance. With a strong focus on performance and quality, he ensures that systems scale smoothly under heavy traffic, delivering reliable, high-quality user experiences while driving innovation in the engineering process.

He is a seasoned engineer and people leader with over 10 years of experience, known for effectively guiding high-performing teams on large-scale projects for high profile companies, such as Adobe. He led cross-functional teams across multiple geographies, delivering impactful projects to millions of users.

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

Milestone 1: Research Stage and CIP Drafting

• Project Manager (5 days @ 600 USD/day): $3,000
• Technical Writer (5 days @ 500 USD/day): $2,500
• Administrative Costs (documentation, CIP submission): $1,200
• Total for Milestone 1: $6,650

Milestone 2: Prototype Development

• Lead Software Developer (23 days @ 800 USD/day): $18,400
• API Development and Testing (8 days @ 700 USD/day): $5,600
• Infrastructure Costs (servers, cloud testing): $2,500
• Total for Milestone 2: $26,500

Milestone 3: API and SDK Finalization

• Software Developer (10 days @ 800 USD/day): $8,000
• Writing Documentation (5 days @ 400 USD/day): $2,000
• Testing and Infrastructure Costs: $2,500
• Total for Milestone 3: $12,500

Milestone 4: VESPR Wallet Integration

• Software Developer (10 days @ 800 USD/day): $8,000
• UI/UX Designer (2.5 days @ 400 USD/day): $1,000
• Backend Infrastructure (server updates, backend adjustments): $1,000
• Testing Resources (QA): $500
• Total for Milestone 4: $10,500

Milestone 5: Beta Release, Community Feedback, and Catalyst Closeout

• Beta Testing Manager (5 days @ 600 USD/day): $3,000
• Bug Fixes and Optimization (10 days @ 800 USD/day): $8,000
• Marketing and Community Engagement: $2,500
• Catalyst Closeout Report and Video: $1000
• Total for Milestone 5: $14,500

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

Our project offers substantial value for the Cardano ecosystem by addressing key challenges in payment processing and transaction requests, while keeping costs aligned with industry standards.

Justification of Costs:

The costs are based on typical contractor rates for skilled professionals, such as developers and are reflective of the complexity of building a robust SDK and deep linking standard. Project management and infrastructure costs are essential to ensure smooth execution, stability, and security in handling Cardano transactions.

Value for Money:

The enhanced deep link standard and SDK will provide long-term benefits by simplifying Cardano payment processes, driving greater adoption across dApps, mobile apps, and physical stores. By empowering developers with easy-to-use tools, the project fosters innovation and expands the real-world utility of ADA.

Proportional Costs:

The budget is proportional to industry norms, ensuring that each resource is optimally allocated without waste. Our careful planning ensures that the project will deliver significant benefits to the ecosystem at a reasonable cost.

Return on Investment for Cardano:

This project will enhance Cardano’s accessibility and usability, fostering broader adoption across various industries. The scalable nature of this solution makes it a valuable addition to the ecosystem, delivering impactful, long-term benefits.