### Terms and Conditions
- [x] I agree to the [Grant Agreement](https://9ba4718…c-5c73-47c3-a024-4fc4e5278803.usrfiles.com/ugd/9ba471_6ff6db4095fd4c4ba21babec361e927e.pdf) terms if funded
- [x] I agree to [Provide KYC information](https://9ba4718c-5c73-47c3-a024-4fc4e5278803.usrfiles.com/ugd/9ba471_7d9e73d16b584a61bae92282b208efc4.pdf) if funded above $50,000 USD
- [x] I agree to disclose conflicts of interest
- [x] I understand that this grant program is only eligible for completed work, as it is a retroactive grant program. Applications for planned or partially completed work will not be considered. All completed work will be verified and accepted by its intended users or their representatives, who will confirm that the outputs meet the required quality, functionality, and usability before the work is listed as an option for Coinholder voting.
- [x] I agree that for any new open-source software, I will create a CONTRIBUTING.md file that reflects the high standards of Zcash development, using the [`librustzcash` style guides](https://github.com/zcash/librustzcash/blob/main/CONTRIBUTING.md#styleguides) as a primary reference.
- [x] I understand when contributing to existing Zcash code, I am required to adhere to the project specific contribution guidelines, paying close attention to any [merge](https://github.com/zcash/librustzcash/blob/main/CONTRIBUTING.md#merge-workflow), [branch](https://github.com/zcash/librustzcash/blob/main/CONTRIBUTING.md#branch-history), [pull request](https://github.com/zcash/librustzcash/blob/main/CONTRIBUTING.md#pull-request-review), and [commit](https://github.com/zcash/librustzcash/blob/main/CONTRIBUTING.md#commit-messages) guidelines as exemplified in the librustzcash repository.
- [x] I understand all grants are valued in USD but will be disbursed in Shielded ZEC. I acknowledge and accept that disbursement amounts may fluctuate based on the ZEC/USD exchange rate at the time of payment.
### Application Owners (@octocat, @octocat1)
@dadybayo
### Organization or Individual Name
Horizontal Systems - Unstoppable Wallet
### Additional Team Members
```team-members.yaml
- Name: Dan Dadybayo
Role: Research & Strategy
- Name: Anton S.
Role: iOS Engineer
- Name: Ermat A.
Role: Lead Engineer
- Name: Chyngyz O.
Role: Android Engineer
- Name: Bakyt A.
Role: Lead Engineer
```
### How did you learn about the Lockbox: Coinholder Retroactive Grants Program?
We are an active wallet contributor to the Zcash ecosystem and our team members regularly engage on the community forum.
### Requested Grant Amount (USD)
$50,000
### Category
Wallets
### Project Summary
We continued expanding Zcash support in Unstoppable Wallet beyond core wallet functionality into a liquidity, execution and distribution layer.
This work enables users to:
- Swap ZEC across chains using aggregated liquidity
- Access multiple liquidity providers through a single interface
- Choose between DEX and CEX providers for swap
- Evaluate execution risk alongside the price and swap duration
- Access ZEC swaps across mobile, web, and messenger bot-based interfaces
- Benefit from improved sync performance and wallet reliability
### Project Description
Following earlier improvements (shielding UX, unified balances, SDK upgrades), we identified two remaining limitations:
- Limited cross-chain liquidity for ZEC
- Operational friction in shielded wallet usage and recovery
To address this, we extended our existing swap aggregation system with additional liquidity sources, routing logic and distribution channels.
We expanded the aggregation layer by integrating:
- On-chain liquidity via DEXes like - NEAR Intents and Maya Protocol
- Additional RFQ providers: LetsExchange, QuickEx, Swapuz, StealthEX, Exolix
This resulted in:
- Broader liquidity coverage and expanded trading pairs
- Improved execution reliability through multiple routing paths
- Increased effective liquidity depth
- Ability to swap ZEC across chains and into a wide range of assets
By combining on-chain and RFQ liquidity, the system enables hybrid routing, improving both execution success rate and flexibility.
We also introduced a provider risk classification system in the swap interface. Each provider is labeled as Auto, Flexible, PreCheck, or Controlled, allowing users to evaluate execution reliability, potential delays or rejections and tradeoffs between price and certainty.
In addition, we expanded swap access across multiple distribution channels:
- Web interface (swap.unstoppable.money)
- Telegram swap bot
- Simplex-based bot
All channels use the same aggregation and routing engine, enabling consistent execution and access to liquidity across environments. We also implemented Zcash-specific improvements:
- Faster sync performance and balance updates
- Shielded address rotation to improve privacy
- Birthday height editing and rescan for reliable recovery
### Technical Approach (how you did it)
We extended our existing swap aggregation infrastructure by integrating additional liquidity sources and implementing a hybrid routing system.
Key components:
- Integration of on-chain routing via NEAR Intents and Maya Protocol
- Integration of multiple RFQ providers into a unified aggregation layer
- Parallel quote querying and route selection logic
- Implementation of a hybrid routing engine combining DEX and RFQ execution paths
We introduced a provider-level risk classification system, assigning each route a predefined execution type (Auto, Flexible, PreCheck, Controlled) based on execution model and expected behavior.
On the Zcash side, we:
- Optimized the sync pipeline for faster initial synchronization and updates
- Implemented shielded address rotation compatible with existing SDK flows
- Added birthday height override and rescan mechanisms for recovery scenarios
We also designed a shared execution layer used across:
- Mobile wallet
- Web interface
- Messaging-based bots
This ensures consistent routing logic and execution behavior across all distribution channels.
### Time Period of Work Completion
Q1 2026 - Q2 2026 - January 2026 - April 2026
### Total Budget (USD)
$50,000
### Budget Breakdown
- Compensation:
- $(USD): 30,000
- Justification: Core engineering and development work extension of the existing aggregation engine, integration of additional liquidity providers (DEX and RFQ), implementation of hybrid routing logic, provider risk scoring system, and Zcash-specific improvements (sync optimization, address rotation, recovery mechanisms), including development of the multi-channel distribution layer (web interface and bot-based integrations).
- Technology/Software:
- $(USD): 10,000
- Justification: UX and UI implementation for swap aggregation, provider selection and risk classification system across mobile, web and bot interfaces.
- Infrastructure/Hosting:
- $(USD): 7,000
- Justification: Integration testing across multiple liquidity providers, routing validation, performance optimization and debugging to ensure reliable cross-chain swap execution.
- Services/Contractors:
- $(USD): 3,000
- Justification: QA, project coordination, release management and monitoring of provider integrations and routing performance.
- Total $(USD): 50,000
### Previous Funding
Yes
### Previous Funding Details
We previously received funding through the Zcash Coinholder Grants program for improving core Zcash support in Unstoppable Wallet.
That work focused on bringing Zcash integration to a stable and production-ready level, including:
- Migration to the latest ECC Zcash SDK
- Implementation of unified shielded (z-address) and transparent (t-address) balance view
- Introduction of a one-tap shielding flow
- Improvements in sync performance, memo handling and transaction reliability
These upgrades were delivered across versions 0.41.0–0.45.0 and are fully open-source. The impact of this work was a significant improvement in usability of shielded transactions, lowering the barrier for users to interact with Zcash’s privacy features.
This proposal represents a continuation of that work, with a shift in scope:
- Previous grant: focused on core wallet functionality, usability and stability of shielded transactions
- Current proposal: focuses on expanding Zcash into liquidity, execution, and distribution layers
Specifically, this includes:
- Extending the existing aggregation system with additional liquidity providers (DEX and RFQ)
- Enabling cross-chain swaps for ZEC
- Introducing provider-level risk awareness in swap execution
- Expanding access through web and bot-based distribution channels
### Other Funding Sources
No
### Other Funding Sources Details
_No response_
### Success Metrics
During this phase, we observed measurable growth in ZEC usage across our products.
- In April alone, over $1.5M in swap volume involving ZEC was processed
- This indicates increasing demand for cross-chain usage of ZEC and growing interest in the asset beyond its native ecosystem
**Usability and reliability improvements**
- Faster sync and improved balance updates
- More reliable recovery via birthday height editing and rescan
- Access to swaps across mobile, web and bot interfaces
**Privacy improvements** (standards-first approach)
We implemented shielded address rotation compatible with existing Zcash SDK flows. We intentionally avoided custom implementations to preserve interoperability between wallets. Some wallets use non-standard approaches, which can limit compatibility and user mobility.
**Risk-aware execution**
We introduced a provider risk classification system, becoming one of the first wallets to surface execution risk in swap routing.
Providers are labeled (Auto, Flexible, PreCheck, Controlled), allowing users to evaluate:
- execution reliability
- potential delays or rejections
- tradeoffs between price and certainty
**Summary**
This work:
- Increased ZEC cross-chain volume
- Improved usability and reliability
- Strengthened privacy practices
- Introduced transparency in swap execution
### Proof of completion
- Repository/Commit:
- [Version 0.47.0](https://github.com/horizontalsystems/unstoppable-wallet-android/releases/tag/0.47.0)
- [Version 0.48.0](https://github.com/horizontalsystems/unstoppable-wallet-android/releases/tag/0.48.0)
- Publication:
- [Post on X ](https://x.com/unstoppablebyhs/status/2043364152060588109)
- Deployment/Release:
- [Google Play Store – Unstoppable Wallet](https://play.google.com/store/apps/details?id=io.horizontalsystems.bankwallet)
[Apple App Store – Unstoppable Wallet](https://apps.apple.com/us/app/unstoppable-crypto-wallet/id1447619907?ls=1)
- Other Evidence:
- [GitHub Repository](https://github.com/horizontalsystems) – full open-source codebase available under MIT license
### Conflict of Interest Disclosure
_No response_
### Community Forum Posting
- [x] I understand it is my responsibility to post a link to this issue on the [Zcash Community Forums](https://forum.zcashcommunity.com/t/about-the-retroactive-grants-category/52106) after this application has been submitted so the community can give input. I understand this is required in order for the community to discuss and vote on this grant application. Note: If you are unable to post on the forum (for example, due to new user restrictions), please leave a comment below, and we will adjust your posting permissions.
