The Bombay Stock Exchange (BSE), on September 25, 2026, notified the introduction of upgraded Trading System APIs as part of its initiative to strengthen market infrastructure, improve efficiency and support innovation. The Exchange will upgrade member-facing interfaces including Enhanced Transaction Interface (ETI), Enhanced Market Data Interface (EMDI) and Enhanced Order Book Interface (EOBI), while Direct NFCAST will remain unchanged. ETI API version 13.0 and EOBI API version 3.0 have been released with updated specifications, message definitions and implementation guidance.
The upgraded ETI API 13.0 introduces decimal quantity support and aligned interface structures. EOBI API 3.0 introduces decimal quantity support, Auction Best Bid/Offer and Auction Top-of-Book messages, Mass Instrument State Change messages, Gateway-In Timestamp (RequestTime), enhanced sequencing and recovery mechanisms, duplicate and gap detection, snapshot synchronisation and failover handling. It also includes additional reference-data and extensibility fields and revised message layouts covering execution summaries, order management, instrument summaries, complex instruments, auctions and instrument state changes.
The new APIs are planned to be made available in the simulation test environment from October 2026, with tentative rollout timelines of Currency Derivatives – October 2026, Equity Derivatives – November 2026 and Equity Cash Market – December 2026. Trading Members, ISVs, algo vendors, data vendors and trading application vendors are encouraged to begin development, testing and readiness activities. The upgraded APIs are independent of the current production environment, which will continue to operate on ETI API 1.6.15 and EOBI API 1.4 until the trading platform upgrade is completed.
[Notice No. 20260925-31]
