How 1inch Fusion powers fast, MEV-protected swaps

The 1inch Fusion protocol, with its intent-based architecture, has set a new standard in DeFi. Thanks to it, users can execute fast, secure crypto swaps and access liquidity across the market.

When you make a swap on 1inch, you’re not just interacting with a simple interface - you’re tapping into a complex execution layer designed to get you the best outcome. At the core of this system sits the 1inch Fusion protocol, the engine that powers how many swaps are actually executed behind the scenes. Instead of sending a standard transaction into the mempool, Fusion uses an intent-based model where professional resolvers compete to fill your order, often covering gas fees and protecting the trade from front-running and other forms of MEV.

This architecture has recently become more visible with the upgrade of the 1inch Swap interface, which gives users more control and transparency over how their trades are executed. But regardless of what you see on the surface, Fusion remains the layer underneath that determines pricing, execution quality and protection. Understanding how it works is key to understanding why 1inch swaps behave differently - and often more efficiently - than standard DeFi trades.

How 1inch Fusion works: intents and smart execution

1inch Fusion leverages an intent-based architecture, a cutting-edge approach in DeFi that focuses on users' goals. This involves users setting intents and market professionals executing them through multi-step operations based on specific criteria. Realized in 1inch Fusion, this approach has set a new standard for efficient token swaps in DeFi.

Fusion is built on the power of 1inch's Aggregation and Limit Order protocols. Just like limit orders, Fusion swaps are executed according to presets established by users, setting rate and duration limits. Orders are filled by resolvers—professional market makers who undergo thorough verification and pay the associated gas fees, freeing users from this burden.

Under the Dutch auction model, Fusion swaps' filling rates decrease over time, influenced by swap volume and selected presets. A smooth rate curve ensures better order fill rates, with rapid transactions possible thanks to the price curve adjusting instantly based on market gas prices. Fusion orders are divided into parts, allowing resolvers to fill them partially, minimizing price impact even for large-volume swaps.

Users can also decide how quickly their orders are executed, offering more flexibility and efficiency compared to regular swaps or limit orders. Resolvers bridge liquidity from multiple sources, including the 1inch Aggregation Protocol, AMMs, PMMs, centralized exchanges and their own sources, ensuring sufficient liquidity for swaps.

Fusion-powered swaps are executed directly by resolvers who combine them with other transactions in a bundle for block inclusion, thus protecting them against MEV bot attacks.

Thanks to its intent-based architecture, 1inch Fusion elevates swaps by offering streamlined, user-centric execution along with no gas fees, optimal token rates, market-wide liquidity bridging, MEV protection and more, providing a seamless and efficient DeFi experience.

1inch Swap API integration

Web3 platforms, projects, wallets, bots and more can leverage the 1inch Swap API, powered by the 1inch Fusion protocol, to offer streamlined and efficient swaps to their users. Available on 1inch Business, this API ensures seamless functionality with a response time below 400 ms, making it one of the fastest on the market.

Enjoy the most efficient swaps on 1inch, powered by 1inch Fusion. Visit 1inch Business if you are interested in integrating the 1inch Swap API or other APIs.