What Are Solvers in Crypto?

Key Functions of Solvers

• Order Matching & Execution: Solvers receive batches of user intents (e.g., trade orders) and compete in auctions to provide the most favorable execution, such as the best price or lowest slippage. The solver offering the best solution wins the right to execute the batch12.
• MEV Protection: Solvers are designed to protect users from Miner Extractable Value (MEV) attacks, such as frontrunning and sandwich attacks, by optimizing trade execution and routing34.
• Profit Incentives: Solvers earn profits through small margins on each transaction and may receive protocol incentives (e.g., COW tokens on CoW Swap). They invest in infrastructure and strategies to outcompete others, often acting similarly to market makers or centralized exchange operators5.
• Decentralization & Competition: In permissionless systems, anyone can become a solver by meeting certain requirements (e.g., staking tokens or being whitelisted). This fosters competition, but over time, the market may centralize around a few sophisticated, well-capitalized solvers675.

How Solvers Work (Example: CoW Protocol)

1. User submits an intent (e.g., a trade order).
2. Intents are batched and an auction is held.
3. Solvers submit solutions for the batch, competing to maximize user surplus.
4. Best solver wins and executes the batch, moving tokens on behalf of users using smart contract permissions12.
5. Compensation: Solvers are rewarded for their services, often in the protocol's native token.

Technical Structure

• Driver: Handles blockchain interactions, prepares data, and executes settlements.
• Solver Engine: Implements algorithms to match orders optimally, considering both on-chain and private liquidity2.

Why Are Solvers Important?

• They abstract away complexity for users, ensuring efficient, secure, and MEV-resistant execution.
• They make blockchain applications more accessible by handling the technical details of transaction fulfillment4.

Example Use Cases

• Trade Execution: Finding the best route and price for token swaps.
• Airdrop Claims: Automating the process of claiming multiple airdrops on behalf of users8.