- Snapshot is a tool used for off-chain governance that allows for gasless voting
Communities create and maintain an individual "space" on Snapshot for their community. Space admins control the specific requirements to submit proposals, as well as the token that controls voting power.
Whenever a proposal is submitted, the system takes a "snapshot" of token balances at that block to apportion voting weight. Any tokens transferred after the snapshot only impact voting power for future proposals. Proposers can set the voting period length, vote options, and proposal description for their Snapshot proposals.
Snapshot users sign messages off-chain to cast their vote, which avoids the need to pay transaction fees. Signed messages are then durably stored via a decentralized file storage solution such as IPFS or Arweave.
The main weakness of this approach is that the votes are not submitted and broadcast on chain, so a trusted entity is required to review the final vote count and enact the results. Projects utilizing snapshot such as Yearn Finance and Sushiswap have generally relied on multisigs with community elected signers and time-lock mechanisms to ensure that votes are executed faithfully.