Fuel v1 logoFuel v1

Fuel v1 is the first Optimistic Rollup live on Ethereum, supporting payments.
Value Locked



Canonically Bridged
Externally Bridged
Natively Minted
  • Tokens
  • Daily TPS
    Coming soon
  • 30D tx count
    Coming soon
  • Stage
    Stage 2
  • Type
    Optimistic Rollup
  • Purpose
  • ...


    Fuel v1 is live on Mainnet

    2020 Dec 31st

    First trustless Optimistic Rollup is live on Mainnet.

    Learn more
    Risk summary
    Risk analysis
    Sequencer failureState validationData availabilityExit windowProposer failure

    State validation

    Fraud proofs (1R)

    Fraud proofs allow actors watching the chain to prove that the state is incorrect. Single round proofs (1R) only require a single transaction to resolve.

    Data availability

    On chain

    All of the data needed for proof construction is published on chain.

    Exit window

    Users can exit funds at any time because contracts are not upgradeable.

    Sequencer failure

    Self sequence

    In the event of a sequencer failure, users can force transactions to be included in the project’s chain by sending them to L1.

    Proposer failure

    Self propose

    Anyone can be a Proposer and propose new roots to the L1 bridge.

    Rollup stage
    Fuel v1Fuel v1 is a
    Stage 2
    Optimistic Rollup.
    Learn more about Rollup stages
    Please keep in mind that these stages do not reflect rollup security, this is an opinionated assessment of rollup maturity based on subjective criteria, created with a goal of incentivizing projects to push toward better decentralization. Each team may have taken different paths to achieve this goal.

    Fraud proofs ensure state correctness

    After some period of time, the published state root is assumed to be correct. For a certain time period, usually one week anyone can submit a fraud proof that shows that the state was incorrect.

    • Funds can be stolen if there is no one that checks the published state. Fraud proofs assume at least one honest and able validator.

    1. Background - Fuel documentation

    All data required for proofs is published on chain

    All the data that is used to construct the system state is published on chain in the form of cheap calldata. This ensures that it will always be available when needed.

    1. Background - Fuel documentation
    State derivation
    Node software

    The node software source code can be found here.

    Genesis state

    The bridge contracts deployments are the genesis state of the rollup chain. The bridge contracts of mainnet and testnet (rinkeby) deployment block number are available here.

    Data format

    The data format details are documented in the Data Structure subsection here.


    The system has a centralized sequencer

    While proposing blocks is open to anyone the system employs a privileged sequencer that has priority for submitting transaction batches and ordering transactions.

    • MEV can be extracted if the operator exploits their centralized position and frontruns user transactions.

    1. Architecture: A High-Level View - Fuel documentation
    2. Mainnet deployment parameters - Fuel documentation

    Users can force any transaction

    Because the block production is open to anyone if users experience censorship from the operator they can propose their own blocks which would include their transactions.

    • Users can be censored if the operator refuses to include their transactions and users lack resources to propose blocks themselves.

    1. Architecture: A High-Level View - Fuel documentation

    Regular exit

    The user initiates the withdrawal by submitting a regular transaction on this chain. When the block containing that transaction is finalized the funds become available for withdrawal on L1. The process of block finalization usually takes several days to complete. Finally the user submits an L1 transaction to claim the funds. This transaction requires a merkle proof.

    1. Withdraw.yulp#L40 - Fuel documentation
    Smart contracts

    The system consists of the following smart contracts:

    This contract stores the following tokens: ETH, DAI, USDC, USDT.

    1. Source code
    Knowledge nuggets
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