Prediction markets are attracting hedge funds, family offices and millions of retail traders. Rain wants to make the infrastructure behind them easier to access.
The decentralized prediction market protocol has released SDK v2 on Arbitrum One, replacing its original development kit with a new system covering market creation, trading, settlement, disputes and resolution.
The SDK is also machine-readable, allowing AI coding agents to interact with Rain's infrastructure and launch applications.
Prediction Markets Are Moving Beyond Retail #
The release comes as prediction markets move deeper into mainstream finance. Platforms such as Kalshi and Polymarket have helped turn event contracts into a significant trading category spanning elections, economics, sports and crypto.
Institutional finance is moving in as well. Cantor Fitzgerald has started offering Kalshi contracts to institutional clients, including hedge funds and family offices, according to The Wall Street Journal.
Yet much of the activity remains concentrated on a handful of large platforms. Rain is taking a different position in the market by providing the underlying infrastructure rather than competing primarily for traders.
"Prediction markets have grown exceptionally over the past few years, but they are still far from what they can become," said Roy Shaham, CEO of Rain Protocol.
"As the market expands, we expect the biggest shift to come from users being less passive and increasingly a part of the building process."
Developers Can Choose How Their Markets Trade #
SDK v2 gives developers greater control over how individual markets operate, including a choice between an automated market maker, or AMM, and an onchain order book.
AMMs use liquidity pools and algorithms to determine prices, while order books match buy and sell orders directly onchain. Rain lets builders choose the structure that fits each market.
The SDK also cuts down on transaction approvals. Users can approve access once and continue trading during the session rather than authorizing every action individually.
Resolution and Disputes Are Built In #
Rain SDK v2 includes infrastructure for resolving markets, managing disputes and handling appeals, removing another layer developers would otherwise have to build themselves.
Users can split collateral into matching Yes and No positions and later convert them back into collateral without affecting the market price. The SDK also provides real-time updates on trades and market activity.
AI Agents Can Build Markets Too #
Rain's SDK and documentation are machine-readable, with agent skills that allow AI coding systems to understand the protocol and build on top of it.
That could make it easier to launch specialized prediction markets without developing every component from scratch. Rain also supports private invitation-only markets, account abstraction, AI-assisted market and dispute resolution and cross-chain functionality.
"Our goal with SDK v2 is to give developers the freedom to build new types of markets, explore new ways they can be used, and shape them around their own ideas," Shaham said.
Rain SDK v2 is now available for developers building on Arbitrum One.