Glossary
Coprocessor
An off-chain service that runs heavy computation over a blockchain's data and returns a verifiable proof, letting smart contracts use results they could never afford to compute on-chain.
A coprocessor is an off-chain compute layer that performs expensive calculations over a blockchain's historical or current state, then hands a smart contract a cryptographic proof that the result is correct. Instead of paying gas to loop over thousands of blocks or events on-chain, a contract asks the coprocessor for the answer and verifies a compact proof — usually a ZK-SNARK — that binds the output to real chain data.
The pattern extends what contracts can do without changing the base protocol: computing time-weighted averages, aggregating a user's activity across many blocks, or running machine-learning inference that would be impossibly costly in the EVM. Because the result is proven rather than trusted, there is no honest-majority or oracle assumption to rely on. Projects such as Axiom, Brevis, and RISC Zero's Bonsai popularised the design, and coprocessors are often paired with rollups and oracles to give applications rich, trust- minimised access to data.