Syndicate is an infrastructure network for building application-specific blockchains (“appchains”) with programmable onchain sequencers. It lets developers control their chain’s network, sequencer, and economics, including custom transaction ordering and permissions, while deploying with rollup frameworks such as Arbitrum Orbit and OP Stack on EVM settlement layers like Ethereum or Base. The stack covers mempool, sequencer, onchain sequencing, translation, rollup execution, and proposing.