ONDC

India’s DPI story is often told through scale. This guide looks at it through structure. It maps the digital rails, protocols, access layers, and public data systems that increasingly shape lending, onboarding, verification, payments, and underwriting in India. From Aadhaar, UPI, DigiLocker, and Account Aggregator to OCEN, ONDC, ULI, and the expanding universe of public data APIs, the guide explains what each layer does, where it fits, and where the gaps still remain.