Building a WhatsApp-native Zcash wallet for Tanzania.
In Tanzania, almost everyone knows how to buy airtime.
A small percentage of this, knows how to buy Zcash.
I don’t think that’s because people don’t value financial privacy. I think it’s because the path to using Zcash is still too complicated for someone who simply wants to send money.
That observation led me to spend the past few months building Pesa Ya Siri—Swahili for “Secret Money.” It is a WhatsApp-native interface for Zcash designed to make private digital cash as familiar and accessible as sending a message or buying an airtime voucher.
The Problem
Tanzania has one of the highest rates of mobile money adoption in Africa. From market vendors and motorcycle taxi riders to small businesses and large retailers, mobile money has become part of everyday life.
The convenience is undeniable, but it comes with a trade-off: every transaction leaves a record. Payment providers maintain detailed transaction histories, creating a financial trail that users have little control over.
For many people this may not seem important. For journalists, activists, small business owners, cross-border traders, or anyone who simply values financial privacy, it matters.
Zcash was designed to address exactly this challenge. Through shielded transactions, it allows users to transact without publicly revealing the sender, recipient, or transaction amount on the blockchain.
The challenge is not the technology—it is accessibility.
For someone new to cryptocurrency, getting started with Zcash typically involves downloading a wallet, securing a recovery phrase, understanding different address types, and finding a reliable way to acquire ZEC.
For many potential users, this is where the journey ends.
Why Zcash, and Why Now?
The upcoming Ironwood network upgrade represents another important milestone in the evolution of Zcash. Rather than building against temporary infrastructure, Pesa Ya Siri is being developed with the intention of integrating directly with the post-Ironwood network, allowing the production version to launch on the latest generation of Zcash shielded technology.
This provides an opportunity to introduce new users to Zcash using modern infrastructure from the outset.
What I Built
Instead of asking users to learn another application, I decided to bring Zcash to a platform they already use every day.
Pesa Ya Siri is a conversational interface for Zcash that operates entirely through WhatsApp.
A user sends CREATE to the Pesa Ya Siri WhatsApp number.
The system creates a wallet associated with their phone number.
From there they can check their balance, send funds to another user, redeem voucher codes, and eventually purchase mobile airtime—all through simple WhatsApp commands.
The goal is not to replace existing Zcash wallets, but to reduce the barriers to entry for first-time users.
A Different Approach to Onboarding
One of the biggest obstacles to cryptocurrency adoption is acquiring digital assets.
Pesa Ya Siri addresses this by introducing a voucher system inspired by the distribution model of traditional airtime scratch cards.
Voucher codes are generated by the platform, printed onto physical scratch cards, and distributed through local vendors.
A customer purchases a voucher using Tanzanian Shillings, scratches the card, and sends the redemption code through WhatsApp. Once validated, the corresponding value in ZEC is credited to the user’s wallet.
The value of each voucher is calculated using live market pricing, with a small pricing buffer to account for market movements between voucher generation and redemption.
Planned denominations include 2,000, 5,000, 10,000, 25,000, and 50,000 Tanzanian Shillings.
For users, the experience is intentionally familiar. They purchase a voucher in much the same way they purchase airtime today, without needing to navigate exchanges or cryptocurrency marketplaces.
Current Project Status
Pesa Ya Siri has progressed beyond the concept stage.
A functional MVP has been completed and is backed by a persistent database.
Current functionality includes:
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Wallet creation
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User registration
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Balance management
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Transaction workflows
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Voucher redemption
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Administrative voucher generation
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Live ZEC price retrieval
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Persistent data storage
The backend is publicly accessible:
https://web-production-fe8ba0.up.railway.app/health
The source code is available on GitHub:
Making the project open source is intentional. It allows anyone in the Zcash community to inspect the implementation, follow its progress, and contribute feedback.
From Prototype to Production
When I first shared this idea with members of the Zcash community, the response was simple:
“Build it first.”
The initial ZCG application on Github
That was good advice.
Rather than continuing to describe the idea, I focused on building a working implementation.
Today, the backend is operational, the chatbot processes real commands, application data persists correctly, and the complete source code is publicly available.
The remaining work is infrastructure.
The current implementation uses mocked blockchain interactions while the surrounding architecture is completed. Following the Ironwood upgrade, the next stage is integrating a production Zcash Full Node, lightwalletd, WhatsApp Business, and commercial airtime services to support live transactions.
What’s Next
The immediate objective is to transition Pesa Ya Siri from a functional MVP into a production-ready pilot.
The next development phase includes:
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Production infrastructure deployment
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Dedicated Zcash Full Node and lightwalletd
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WhatsApp Business integration
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Airtime API integration
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Production security and monitoring
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Swahili educational content
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Pilot deployment with real users
To support this work, I will be applying for an initial grant through ZecHub.
Why This Matters
Technology is adopted when it fits naturally into people’s existing habits.
In Tanzania, WhatsApp is already how people communicate.
Airtime vouchers are already how many people purchase digital value.
Pesa Ya Siri brings those familiar experiences together with the privacy guarantees provided by Zcash.
The objective is not simply to build another wallet. It is to make private digital cash accessible to people who may never have considered using cryptocurrency before.
The MVP is complete.
The code is public.
The next step is connecting the platform to the live Zcash network and validating it through real-world use.
If you’re part of the Zcash ecosystem, I’d genuinely value your feedback. Whether it’s technical criticism, questions about the architecture, or ideas for improving the user experience, those conversations will help shape the next phase of the project.
Asante sana.
Clemence Douglas