{"slug": "gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets", "title": "Gemini introduces Custom Combos RFQ API for beta testing in prediction markets push", "summary": "Gemini has launched Custom Combos, a sealed-bid Request-for-Quote (RFQ) API for multi-leg prediction market contracts, now in beta testing in its sandbox environment. The system gives market makers a 1-second window to submit quotes, the requester 5 seconds to accept, and the winning maker a 1-second confirmation, completing trades in about 7 seconds. Gemini entered prediction markets in late 2025, and Custom Combos differentiate it from rivals Kalshi and Polymarket, which rolled out similar combo features earlier in 2026.", "body_md": "Via gemini.com\n\n# Gemini introduces Custom Combos RFQ API for beta testing in prediction markets push\n\nThe crypto exchange's new sealed-bid auction system for multi-leg prediction contracts enters sandbox testing as competition heats up with Kalshi and Polymarket\n\nGemini is rolling out a new trading tool that brings Wall Street-style execution mechanics to prediction markets. The exchange’s Custom Combos feature, now live for beta testing in its sandbox environment, lets market makers submit sealed bids on multi-leg prediction market contracts through a Request-for-Quote API.\n\n## How the system actually works\n\nThe RFQ process runs on a tight clock. Market makers get a 1-second window to submit their quotes after a request comes in. The requester then has 5 seconds to accept the best bid. Finally, the winning maker gets a 1-second “last-look” confirmation period to finalize the trade.\n\nThat entire lifecycle runs through a series of defined states: OPEN, PENDING_ACCEPTANCE, CONFIRMING, and FINALIZING. The whole thing wraps up in roughly 7 seconds.\n\nThe sealed-bid design means competing market makers can’t see each other’s quotes. Only the winning bid gets disclosed after the auction concludes.\n\nContracts require at least two legs, which means traders can construct custom combinations of prediction market positions rather than being limited to single-outcome bets.\n\nProduction access remains locked down during this controlled beta phase. Developers and market makers can only integrate and test through the sandbox environment. Gemini’s documentation for the feature was last updated on August 11, 2026, laying out the full operational flow, messaging formats, and timing specifications.\n\n## The prediction markets arms race\n\nGemini entered the prediction markets space in late 2025, and Custom Combos represent its bid to differentiate in an increasingly crowded field. Kalshi and Polymarket both rolled out similar combo capabilities earlier in 2026.\n\nWhere Gemini’s approach diverges is in the execution model. Rather than matching orders on a central limit order book, the RFQ system creates a private marketplace where institutional liquidity providers compete for flow.\n\n**Disclosure:** This article was edited by Editorial Team. For more information on how we create and review content, see our\n\n[Editorial Policy](https://cryptobriefing.com/editorial-policy/).", "url": "https://wpnews.pro/news/gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets", "canonical_source": "https://cryptobriefing.com/gemini-custom-combos-rfq-api-beta/", "published_at": "2026-08-11 16:55:35+00:00", "updated_at": "2026-08-11 17:25:51.108836+00:00", "lang": "en", "topics": ["ai-products", "ai-tools"], "entities": ["Gemini", "Kalshi", "Polymarket"], "alternates": {"html": "https://wpnews.pro/news/gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets", "markdown": "https://wpnews.pro/news/gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets.md", "text": "https://wpnews.pro/news/gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets.txt", "jsonld": "https://wpnews.pro/news/gemini-introduces-custom-combos-rfq-api-for-beta-testing-in-prediction-markets.jsonld"}}