Frame Overview

Frame is an Ethereum rollup.

Rollups are a layer 2 scaling solution built on top of Ethereum. Frame is EVM-compatible which means you can do anything on Frame that you would be able to do on Ethereum mainnet - deploy contracts, use Web3 apps, interact with wallets, etc. However, because Frame is a rollup, transactions will be cheaper and faster compared to Ethereum. Frame is an optimistic rollup which means it inherits many security properties from Ethereum.

How Rollups Work

The core idea behind a rollup is to move computation from one blockchain (such as Ethereum) onto another blockchain (the rollup) which can process transactions quicker. Rollups will execute transactions, compress and bundle the transaction data, and post this data back to the underlying blockchain (the layer 1). This data is utilized by rollup nodes to derive the correct state of the chain, as well as by the Layer 1 network to determine the validity of withdrawals.

Most rollups today have a centralized sequencer that quickly takes incoming transactions, orders the transactions, and publishes the ordering for other nodes to consume. The sequencer can process transactions quickly, which is why transactions are faster on rollups compared to mainnet (1-2 secs vs 12 secs). Users can alternatively submit transactions directly to the rollup bridge contract on L1 if they do not trust the sequencer. However, this process is slower and more expensive than submitting to a sequencer, and should only be used for deposits or in the case of a malicious sequencer.

Optimistic Rollup

Frame is an optimistic rollup which means it uses "fraud proofs" to determine whether withdrawals from the network are valid. Optimistic rollups assume that all transactions are valid by default, hence the "optimism". However, any party can submit a fraud proof to prove that a state transition in the chain is invalid. Transactions than involve L2 to L1 communication (including withdrawals) need to wait for the dispute window (~7 days) to pass before being finalized. This 7 day dispute window gives validators enough time to submit fraud proofs without being griefed from dishonest parties.

Rollup Tech

Frame is built using Arbitrum's Nitro stack (opens in a new tab). Nitro is the latest version of Arbitrum technology which includes a complete optimistic rollup system, a sequencer, token bridges, fraud proofs, and more. Complete documentation of Nitro can be found on Github (opens in a new tab).

Nitro is EVM compatible, so contracts that are written for mainnet can be deployed onto Frame without any modifications. Applications requiring read or write access to Frame can employ the same processes used on mainnet, with the only difference being a different RPC and chain ID.