Public-works programmes are widespread in developing countries, in part because this form of social protection is potentially self-targeting. However, public works can also be administratively demanding, costly and corrupt. This study pilots a proposed welfare scheme designed to retain the self-targeting aspect of public works while improving accessibility and reducing operational complexity and fraud: beneficiaries are paid to solve educational micro-tasks on a smartphone. Hence, while participants in traditional public-works schemes typically build or maintain physical infrastructure, participants in the piloted scheme would build their own human capital. In a randomised-controlled trial in Karnataka, South India, it recruited 114 illiterate workers with experience of India’s flagship public-works scheme. The treatment group was given access to the pilot scheme for a week. The intervention increased the number of characters recognised from the local script by 65%, and more than half the test users reported preferring the piloted scheme over the exist- ing public-works programme. It also reports on an earlier pilot that had no effect on character recognition, probably due to an overly ambitious ‘syllabus’.