ONDC Integration Guide for Sellers and D2C Brands
How ONDC works, the choice between joining through a seller app and building your own, the protocol flow, testing and what the integration demands of catalogue, orders and logistics.
ONDC is not a marketplace or an app. It is an open network where any buyer app can discover and order from any seller app using a common protocol. A brand listed once becomes visible in every buyer app on the network, and can choose logistics from providers on the same network.
How the network is organised
The network unbundles what a marketplace does into separate roles.
Two ways to join
Most sellers do not need to write protocol code.
Join through a seller app first. Build your own when order volume justifies it.
The protocol flow
ONDC uses the Beckn protocol. Every action is an asynchronous pair: the buyer side calls an API and the seller side replies through a callback. Each message is digitally signed and verified against the registry.
Building your own seller app
If you take the direct route, plan for these components.
Testing and going live
Integration moves through staging, pre-production and production environments. You register on the participant portal, generate signing keys, subscribe to the registry and run the required flows for your domain, such as grocery, food and beverage or fashion. Certification involves submitting logs of each flow for verification before production access is granted. Each domain has its own mandatory attributes and scenarios.
What it demands operationally
Buyer apps rank and suppress sellers on fulfilment performance, so the technical integration is only half the work. Inventory must be accurate, orders accepted within the time limits, and cancellations kept low. Product data needs the attributes the network requires, including statutory details for packaged goods and food licences for food sellers.
This article explains what to build, not legal advice. Rules change; confirm against the current official text before relying on it.
