# Facet Markdown version of https://l2beat.com/layer2s/projects/facet ## Summary - Total Value Secured: $704.66 K (+0.42% compared to seven days ago; canonically bridged $0.00, natively minted $0.00, externally bridged $704.66 K; 99.9% with additional trust assumptions compared to the tokens involved and the Stage assigned to the project's canonical messaging bridge) - Past day UOPS: <0.01 (-5.26% compared to seven days ago) - Stage: Stage 2 - Gas token: FCT - Type: Optimistic Rollup - Purpose: Universal - Host chain: Ethereum - Chain ID: 1027303 ### Risks - Sequencer failure: Self sequence (sentiment: good) - State validation: Fraud proofs (1R, ZK) (sentiment: good) - Data availability: Onchain (sentiment: good) - Exit window: ∞ (sentiment: good) - Proposer failure: Self propose (sentiment: good) ### About Facet is a based rollup built on OP-Succinct. It uses FCT as its native gas token, which is mintable by burning ETH on L1. ## Value Secured Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/layer2s/projects/facet#tvs). - [TVS chart (JSON)](https://l2beat.com/api/scaling/tvs/facet) - [TVS breakdown by token (JSON)](https://l2beat.com/api/scaling/tvs/facet/breakdown) ## Activity Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/layer2s/projects/facet#activity). - [Activity chart (JSON)](https://l2beat.com/api/scaling/activity/facet) ## Onchain costs Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/layer2s/projects/facet#onchain-costs). ## Liveness Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/layer2s/projects/facet#liveness). ## Milestones & Incidents - 2026-05-18: [Rollup redeployed](https://etherscan.io/address/0x026902ef5a0931f25cbb78b5dd7a72ee998569ae). New Rollup contract takes over state-root proposals with a new SP1VerifierGateway. - 2025-07-02: [SP1 proof system deployed](https://etherscan.io/tx/0x2c76f9fb8d18290ae8d75b8bcfe6ee2bd5a7548983fa1d400f83ed9db11d0b84). Facet launches its optimistic rollup contract with SP1 zk fault proofs. - 2024-12-10: [Mainnet Launch](https://x.com/0xFacet/status/1866610169620336761). Facet launches at Ethereum block 21373000. ## Risk analysis ### Sequencer failure Self sequence (sentiment: good) Users can self sequence transactions by sending them on L1. There is no privileged operator. ### State validation Fraud proofs (1R, ZK) (sentiment: good) Actors watching the chain can challenge state proposals, and challenged proposals must provide ZK proofs. SNARKs are zero knowledge proofs that ensure state correctness, but require trusted setup. ### Data availability Onchain (sentiment: good) All of the data needed for proof construction is published on Ethereum L1. ### Exit window ∞ (sentiment: good) Users can exit funds at any time because contracts are not upgradeable. ### Proposer failure Self propose (sentiment: good) Anyone can propose blocks if accompanied by a validity proof. Only the whitelisted proposers can propose state roots for recent blocks optimistically. Anyone can propose optimistically for L2 blocks that are older than 14d. ## Stage Facet is a Stage 2 Optimistic Rollup. ### Scope of assessment #### In scope - Sequencing mechanism via L1 through the Inbox and state validation mechanism via the Rollup proof system - The Rollup contract and its upgradability #### Not in scope - Bridges built on top of the Rollup, including the legacy L1Bridge (eth:0x4e2eba30…, immutably bound to the deprecated Rollup) and the operator-controlled FacetEtherBridgeV6 fast bridge — each bridge carries its own trust assumptions and must be assessed separately - Bridged token compatibility with other DeFi applications e.g., Bluebird WETH (BBWETH) - The soundness of the ZK proof system of Rollup ### Stage 0 - [x] A complete and functional proof system is deployed. - [x] The project calls itself a rollup. - [x] State roots are posted to Ethereum L1. - [x] Inputs for the state transition function are posted to Ethereum L1. - [x] A source-available node exists that can recreate the state from Ethereum L1 data. Please note that the L2BEAT team has not verified the validity of the node source code. [View code](https://github.com/0xFacet/facet-op-succinct) ### Stage 1 - [x] Principle: Compromising ≥75% of the Security Council is the only way (other than bugs) for a rollup to indefinitely block an L2→L1 message (e.g. a withdrawal) or push an invalid L2→L1 message (e.g. an invalid withdrawal) with a <7d exit window. - [x] Users are able to exit without the help of the permissioned operators. - [x] In case of an unwanted upgrade by actors more centralized than a Security Council, users have at least 7d to exit. - [x] The proof system meets the minimum trusted setup requirements defined in the L2BEAT [trusted setup assessment framework](https://forum.l2beat.com/t/the-trusted-setups-framework-for-zk-catalog/381). - [x] Prover source code is published. - [x] Onchain verifiers' smart contracts can be independently regenerated from the verifier source code. - [x] The sources of all programs used are public and program hashes can be independently regenerated. ### Stage 2 - [x] Fraud proof submission is open to everyone. - [x] Upgrades unrelated to onchain provable bugs provide at least 30d to exit. ## State validation Facet implements a dual-track proving system that combines optimistic proposals with bonds with ZK validity proofs. The system allows bypassing the 7-day fraud proof window by providing a ZK proof. ### Challenges The system operates on two parallel tracks: an optimistic track where whitelisted proposers submit state roots with ETH bonds that can be challenged within a time window, and a validity-proof track where anyone can submit direct ZK proofs for immediate resolution. Validity proofs bypass the optimistic flow and can invalidate multiple incorrect optimistic proposals simultaneously targeting the same state root. When optimistic proposals are challenged, proposers must defend their claims by providing ZK proofs within the proving window. ### Validity proofs The system uses Succinct's SP1 zkVM and Prover Network to generate zero-knowledge proofs that verify L2 state transitions. Anyone can submit a validity proof through the proveBlock() function of the Rollup contract to bypass the optimistic flow and settle an anchor block. Submitting a validity proof during a challenge settles the dispute in a single transaction. **References** - [Facet ZK Fault Proofs - GitHub Repository](https://github.com/0xFacet/zk-fault-proofs) ## Updates Shown as an interactive chart or widget on [the HTML page](https://l2beat.com/layer2s/projects/facet#updates). ## Operator ### There is no central operator There is no privileged entity that sequences transactions or produces blocks. This activity is permissionless and open to anyone. ### Users can force any transaction Because the state of the system is based on transactions submitted on the underlying host chain and anyone can submit their transactions there it allows the users to circumvent censorship by interacting with the EOA inbox on the host chain directly. ## Sequencing ### Based Sequencing Facet uses a based sequencing model where transaction ordering is determined entirely by Ethereum L1. Users submit transactions to an immutable address on Ethereum with transaction information encoded as RLP calldata. Facet blocks preserve the exact order in which Ethereum includes these transactions. Additionally, L1 smart contracts can create Facet transactions by emitting events with the Facet event signature, where the event data payload contains the same RLP-encoded transaction data. **References** - [Facet Inbox Address - Etherscan](https://etherscan.io/address/0x00000000000000000000000000000000000face7) ## Withdrawals ### Regular messaging The user initiates L2->L1 messages by submitting a regular transaction on this chain. When the block containing that transaction is settled, the message becomes available for processing on L1. The process of block finalization takes a challenge period of 7d to complete. The challenge period can be shortened if the block is proven by providing a ZK proof. ## Other considerations ### No canonical bridge Facet's `Rollup` contract publishes L2 state roots but is not paired with a canonical bridge escrow. Anyone can deploy a bridge that reads the `Rollup`'s anchor state root to bridge arbitrary tokens; each bridge has its own L2 counterpart, so the same L1 token bridged through different bridges results in different L2 representations. Trust assumptions (operator role, upgradeability, withdrawal logic) are bridge-specific and do not propagate from the `Rollup`. The risk analysis on this page covers the `Rollup` and its proof system only; any bridge built on top must be assessed separately. Known bridges today include the `FacetEtherBridgeV6` fast ETH bridge, whose withdrawals are processed by a permissioned EOA operator and do not depend on the `Rollup` state, and a legacy `L1Bridge` immutably bound to `RollupDeprecated`, which no longer receives state-root proposals. **References** - [Rollup - Etherscan](https://etherscan.io/address/0x026902ef5a0931f25cbb78b5dd7a72ee998569ae) - [FacetEtherBridgeV6 (fast bridge) - Etherscan](https://etherscan.io/address/0x0000000000000b07ED001607f5263D85bf28Ce4C) - [Legacy L1Bridge - Etherscan](https://etherscan.io/address/0x4e2eba30a786c0643699b92234d74a71e958c08e) ### Gas Token Minting Facet uses FCT as its native gas token, which is minted through L1 gas consumption rather than being pre-minted. FCT issuance is directly tied to the amount of L1 ETH burned to pay calldata gas in Ethereum transactions, calculated as: FCT minted = ETH burned for calldata × mint rate ETH burned for calldata = L1 base fee × (total L1 gas cost - 21,000) The system targets issuing ~78,300 FCT every 500 Facet blocks. If less than the target is minted in 500 blocks, the mint rate increases proportionally (up to a maximum 4x increase). If the target is reached in fewer than 500 blocks, the mint rate decreases proportionally (up to a maximum 75% decrease). The maximum supply of FCT is ~1.65B. Once 50% of the supply is minted, the per-period target (now ~78,300) will be halved. It will be halved again at 75%, then at 87.5%, and so forth. The period target and period length are selected so that halvings will occur approximately every 5,256,000 blocks. This mechanism is similar to standard OP Stack guaranteed gas markets, where L1 gas is burned to purchase L2 gas for deposits through an EIP-1559-style fee market. However, on Facet, gas purchased in this way accrues to the purchaser's native balance on the L2, whereas in the OP Stack it can only be used for a single transaction. ![Facet Token Minting and Bridging](https://l2beat.com/images/other-considerations/facet.png#center). **References** - [FCT Issuance Formula - Facet Documentation](https://docs.facet.org/native-gas-token/fct-issuance-calculation) - [OP Stack Guaranteed Gas Market Specification](https://specs.optimism.io/protocol/guaranteed-gas-market.html?highlight=gas#rationale-for-burning-l1-gas) ## Permissions ### Ethereum #### Actors ##### Facet Multisig Addresses: [0xb2B01DeCb6cd36E7396b78D3744482627F22C525](https://etherscan.io/address/0xb2B01DeCb6cd36E7396b78D3744482627F22C525) A Multisig with 2/3 threshold. It uses the following modules: FacetSafeModule (Module that allows the Safe to send Facet transactions). * Can interact with Rollup * can set the whitelisted proposers * Can interact with RollupDeprecated * can set the whitelisted proposers ##### EOA 1 Addresses: [0x615452db5467849689E98a8C5C242A96cF768a94](https://etherscan.io/address/0x615452db5467849689E98a8C5C242A96cF768a94) * Can interact with Rollup * Can propose state roots optimistically without a ZK proof. Note that anyone can propose with a ZK proof, and anyone can propose optimistically after the fallback timeout * Can interact with RollupDeprecated * Can propose state roots optimistically without a ZK proof. Note that anyone can propose with a ZK proof, and anyone can propose optimistically after the fallback timeout ## Smart contracts ### Ethereum #### Rollup Addresses: [0x026902EF5a0931F25cbB78b5dd7a72EE998569AE](https://etherscan.io/address/0x026902EF5a0931F25cbB78b5dd7a72EE998569AE#code) Core rollup contract that manages the state of the rollup and its ZK fault proof system. * Roles: * **owner**: Facet Multisig * **whitelistedProposers**: EOA 1 #### RollupDeprecated Addresses: [0x686E7d01C7BFCB563721333A007699F154C04eb4](https://etherscan.io/address/0x686E7d01C7BFCB563721333A007699F154C04eb4#code) Core rollup contract that manages the state of the rollup and its ZK fault proof system. * Roles: * **owner**: Facet Multisig * **whitelistedProposers**: EOA 1 #### L1Bridge Addresses: [0x4E2eBa30a786c0643699b92234d74a71e958C08E](https://etherscan.io/address/0x4E2eBa30a786c0643699b92234d74a71e958C08E#code) An immutable ETH bridge built on top of a Rollup contract. Facet does not designate any single canonical bridge — multiple bridges of this kind can exist in parallel against a given Rollup, and each must be assessed independently. Note that the token received on L2 has a different ticker/symbol than the token sent on L1. #### L1ETHLockbox Addresses: [0x8F75466D69a52EF53C7363F38834bEfC027A2909](https://etherscan.io/address/0x8F75466D69a52EF53C7363F38834bEfC027A2909#code), [0x77764Bdf2B52C4B2635A73927945541B65DF74E9](https://etherscan.io/address/0x77764Bdf2B52C4B2635A73927945541B65DF74E9#code) (Implementation (Upgradable)), [0xe2A3bda6CD571943DD4224d0B8872e221EB5997C](https://etherscan.io/address/0xe2A3bda6CD571943DD4224d0B8872e221EB5997C#code) (Admin) Deprecated entry point to deposit ERC20 tokens from host chain to this chain. Currently just holds ETH that the Facet multisig can withdraw. #### FastExternalBridge Addresses: [0x0000000000000b07ED001607f5263D85bf28Ce4C](https://etherscan.io/address/0x0000000000000b07ED001607f5263D85bf28Ce4C#code), [0x68c56f4D88846A4Cdce966d92D92a0636baf40FE](https://etherscan.io/address/0x68c56f4D88846A4Cdce966d92D92a0636baf40FE#code) (Implementation (Upgradable)), [0x0000000000000000000000000000000000000000](https://etherscan.io/address/0x0000000000000000000000000000000000000000#code) (Admin) A Facet implementation of the ETH Bridge. This bridge is also called "fast bridge" as it uses a permissioned EOA as operator for faster withdrawal processing. #### SP1Verifier Addresses: [0x0459d576A6223fEeA177Fb3DF53C9c77BF84C459](https://etherscan.io/address/0x0459d576A6223fEeA177Fb3DF53C9c77BF84C459#code) Verifier contract for SP1 proofs (v5.0.0). #### FacetSafeModule Addresses: [0x3235AdE33cF7013f5b5A51089390396e931e6BCF](https://etherscan.io/address/0x3235AdE33cF7013f5b5A51089390396e931e6BCF#code) Module that allows the Safe to send Facet transactions. #### SP1Verifier Addresses: [0x50ACFBEdecf4cbe350E1a86fC6f03a821772f1e5](https://etherscan.io/address/0x50ACFBEdecf4cbe350E1a86fC6f03a821772f1e5#code) Verifier contract for SP1 proofs (v5.0.0). #### SP1VerifierGatewayDeprecated Addresses: [0x70C7FdB9e543bD15cd392df04e6d4BD05AfD8A66](https://etherscan.io/address/0x70C7FdB9e543bD15cd392df04e6d4BD05AfD8A66#code) This contract is the router for zk proof verification. It stores the mapping between identifiers and the address of onchain verifier contracts, routing each identifier to the corresponding verifier contract. #### SP1VerifierGateway Addresses: [0xa236E6E31d94b613923d18313f534CE5b6b98eE1](https://etherscan.io/address/0xa236E6E31d94b613923d18313f534CE5b6b98eE1#code) This contract is the router for zk proof verification. It stores the mapping between identifiers and the address of onchain verifier contracts, routing each identifier to the corresponding verifier contract. #### FacetSafeProxy Addresses: [0xC9F2d55C56Ef9fE4262c4d5b48d8032241AF4d25](https://etherscan.io/address/0xC9F2d55C56Ef9fE4262c4d5b48d8032241AF4d25#code) Helper of the Safe Module that allows to send Facet transactions. ### Facet #### L2Bridge Addresses: [0x016bE6d77b783aBdDccaF3fea49ffa9c1CA660D4](https://explorer.facet.org/address/0x016bE6d77b783aBdDccaF3fea49ffa9c1CA660D4#code) ERC20 minter counterpart to an L1 bridge. Mints new ERC20 tokens on L2 once a token deposit is made on L1. Facet does not designate any single canonical bridge — multiple bridges of this kind can exist in parallel against a given Rollup, and each must be assessed independently. Note that the token received on L2 could have a different ticker/symbol than the token sent on L1. #### L2ToL1MessagePasser Addresses: [0x4200000000000000000000000000000000000016](https://explorer.facet.org/address/0x4200000000000000000000000000000000000016#code), [0xC0D3C0d3C0d3c0d3C0d3C0D3c0D3c0d3c0D30016](https://explorer.facet.org/address/0xC0D3C0d3C0d3c0d3C0d3C0D3c0D3c0d3c0D30016#code) (Implementation (Upgradable)), [0x4200000000000000000000000000000000000018](https://explorer.facet.org/address/0x4200000000000000000000000000000000000018#code) (Admin) L2 -> L1 message passer at the OP Stack predeploy address, used by L1Bridge-style canonical bridges to relay withdrawal requests from L2 to L1.