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Sarafu Network

Sarafu Network helps communities exchange digital vouchers that represent commitments to provide goods, services, or labor. The implementation covered here uses Celo, which became an Ethereum layer 2 network in March 2025.

84% of 855 active users surveyed in April–June 2025 reported a positive income effect from Sarafu

Community exchange · Kenya

Institutional context

Communities can have goods, skills, and time available while lacking enough conventional money to coordinate exchange. Grassroots Economics developed community-currency programs in Kenya to help participants use that local capacity and support mutual aid.

Sarafu builds on this approach through Community Asset Vouchers: digital records of commitments by individuals, groups, and businesses to provide goods, services, or labor.

System design

A participant issues vouchers representing an agreed commitment, such as goods, services, or labor. Other participants can receive and transfer those vouchers. Vouchers can also be exchanged through shared pools that define which vouchers can be exchanged and under what conditions, including any limits on exchanges. These shared exchange arrangements are called commitment pools.

Grassroots Economics provides open-source software, smart contracts, and interfaces for this system. The system can also connect services such as USSD, the menu-based technology used on basic mobile phones, to the underlying digital records. This allows people to use Sarafu without directly interacting with blockchain software. That convenience introduces an operator responsible for the service and custody arrangement.

The voucher record does not itself provide the promised goods or labor. Issuers and communities still agree on what a voucher represents, how it can be redeemed, and what happens when a commitment is not fulfilled.

Ethereum’s role

The Sarafu implementation covered here uses smart contracts on Celo to manage vouchers and exchange pools. Celo operated as a separate blockchain during the earlier part of the period covered by this case study. On 26 March 2025, it became an Ethereum layer 2 network, processing transactions separately while relying on Ethereum for security. Earlier activity should therefore not be described as activity on an Ethereum layer 2.

Public records allow exchanges and the rules governing exchange pools to be independently reviewed. The technology does not replace local governance. Communities still determine which vouchers they accept, how exchanges are governed, how commitments are fulfilled, and who is responsible when problems arise.

Status and milestones

  1. 21 July 2025

    Grassroots Economics published findings from phone interviews with 855 active users in April–June 2025. Among respondents, 84% reported a positive effect on their income, 74% reported increased savings, and 78% said Sarafu enabled purchases they otherwise could not have made.

  2. 20 July 2025

    The project’s Celo snapshot records 26,367 users and 285,197 peer-to-peer exchanges since 5 July 2023.

  3. 26 March 2025

    Celo moved from operating as an independent blockchain to operating as an Ethereum layer 2, a network that processes transactions separately while relying on Ethereum for security.

  4. 30 October 2024

    Grassroots Economics reported 33 commitment pools, 239 vouchers, and 3,149 monthly active users as of September 2024, alongside community labor and environmental activities.

  5. July 2023

    Grassroots Economics moved its technology to Celo, according to its subsequent implementation report.

Implementation considerations

A voucher is only useful when participants accept it and its issuer can honor the underlying commitment. Pool rules, redemption expectations, and ways to resolve disagreements are as important as the software.

Services that manage accounts on behalf of users can make participation easier, but they also create dependence on the service operator and require clear arrangements for access, recovery, and accountability. Public transaction data requires care to avoid exposing sensitive community relationships.

Sources