OpenRouter introduced the Fusion API on 2026-06-13, positioning it as a cost-efficient compound model that matches Fable’s intelligence while costing half as much. The announcement (amplified by @pedrouid) labels Fusion the market’s “smartest compound model” and includes a linked thread promising technical details on how it works.
OpenRouter announced the Fusion API (shared by @pedrouid on 2026-06-13), branding it as “the smartest compound model in the market.”
OpenRouter cooked with this one 👌
OpenRouter (@OpenRouter)
Introducing the Fusion API, the smartest compound model in the market.
Fusion achieves Fable-level intelligence at half the price.
How it works 👇
— https://nitter.net/OpenRouter/status/2065856853989270011#m