# ApeChain

Markdown version of https://ethbeat.org/layer2s/projects/apechain

## Summary

**Warning:** Critical contracts can be upgraded by an EOA which could result in the loss of all funds.

**Warning:** Why is the project listed in others? There are less than 5 external actors that can submit challenges. Consequence: projects without a sufficiently decentralized set of challengers rely on few entities to safely update the state. A small set of challengers can collude with the proposer to finalize an invalid state, which can cause loss of funds. Learn more about the [recategorisation](https://medium.com/l2beat/framework-update-l2-projects-recategorisation-5d43b0d1fe50).

- Total Value Secured: $13.93 M (-8.09% compared to seven days ago; canonically bridged $0.00, natively minted $0.00, externally bridged $13.93 M; 100% with additional trust assumptions compared to the tokens involved and the Stage assigned to the project's canonical messaging bridge)
  - **Warning:** The APE token associated with ApeChain accounts for 100% of the TVS! (sentiment: bad)
- TVS by asset: Other $13.93 M (100%)
- Associated tokens: APE: $13.93 M (100% of TVS)
- Past day UOPS: 1.01 (+1.13% compared to seven days ago)
- Gas token: APE
- Type: Other
- Purpose: Universal
- Host chain: Arbitrum One
- Chain ID: 33139
- Risks shown: combined with host chain Arbitrum One; Risk analysis also lists each separately

### Risks

- Sequencer failure: Self sequence (sentiment: good)
- State validation: Fraud proofs (INT) (6d 8h challenge period; sentiment: bad)
- Data availability: External (DAC) (sentiment: bad)
- Exit window: None (sentiment: bad)
- Proposer failure: Self propose (sentiment: good)

### About

ApeChain is an Optimistic Rollup built on the Arbitrum Orbit stack utilizing $APE as its native gas token. It fuels culture by being the chain for digital and IRL communities, builders, creators, collectors, gamers and beyond.

### Links

- Website: https://apechain.com/
- Bridge: https://apechain.com/portal
- Docs: https://docs.apechain.com/
- Explorer: https://apescan.io/
- Repository: https://github.com/ape-foundation
- Social: https://twitter.com/apecoin, https://discord.gg/apecoindao, https://t.me/apechainofficial
- Contracts explorer (Disco): https://disco.l2beat.com/ui/p/apechain

### Badges

- EVM: This project uses the Ethereum Virtual Machine to run its smart contracts and supports the Solidity programming language
- Data Availability Committee: There is a Data Availability Committee that provides/attests to data availability
- Espresso: This project is posting its data to Espresso
- Built on Arbitrum Orbit: The project is built on Arbitrum Orbit
- Built on top of Arbitrum: The project has Arbitrum as its host chain
- Espresso Preconfs: The project integrates with Espresso preconfirmations. The chain batch poster publishes blocks to Espresso Network and runs in a Trusted Execution Environment (TEE) programmed to verify that only Espresso-validated batches reach the host chain.
- Caldera: This project was deployed via the rollup-as-a-service provider Caldera

## Value Secured

The interactive TVS charts are shown on [the HTML page](https://ethbeat.org/layer2s/projects/apechain#tvs).

Token by token: [TVS breakdown](https://ethbeat.org/layer2s/projects/apechain/tvs-breakdown).

- [TVS chart (JSON)](https://ethbeat.org/api/scaling/tvs/apechain)
- [TVS breakdown by token (JSON)](https://ethbeat.org/api/scaling/tvs/apechain/breakdown)

## Activity

The interactive activity chart is shown on [the HTML page](https://ethbeat.org/layer2s/projects/apechain#activity).

- [Activity chart (JSON)](https://ethbeat.org/api/scaling/activity/apechain)

## Milestones & Incidents

- 2024-10-19: [Mainnet Launch](https://x.com/apecoin/status/1847731593437155673). ApeChain launches its Mainnet.

## Risk summary

There are 3 additional risks coming from the host chain [Arbitrum One](https://ethbeat.org/layer2s/projects/arbitrum)

**Warning:** The project relies on program hashes that could not be successfully reproduced from their published sources (CRITICAL).

**Warning:** Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.

### Funds can be stolen if

1. a contract receives a malicious code upgrade. There is no delay on code upgrades (CRITICAL),
2. none of the whitelisted verifiers checks the published state. Fraud proofs assume at least one honest and able validator (CRITICAL).

### Funds can be lost if

3. the sequencer posts an unavailable transaction root (CRITICAL),
4. the data is not available on the external provider (CRITICAL),
5. the external data becomes unavailable (CRITICAL).

### Users can be censored if

6. the committee restricts their access to the external data.

### MEV can be extracted if

7. the operator exploits their centralized position and frontruns user transactions.

## Risk analysis

The L3 risks depend on the individual properties of L3 and those of the host chain combined.

**Warning:** Critical contracts can be upgraded by an EOA which could result in the loss of all funds.

**Warning:** Fraud proof system is fully deployed but is not yet permissionless as it requires Validators to be whitelisted.

|  | Sequencer failure | State validation | Data availability | Exit window | Proposer failure |
| --- | --- | --- | --- | --- | --- |
| Arbitrum One (L2) | Self sequence (sentiment: good) | Fraud proofs (INT) (sentiment: good) | Onchain (sentiment: good) | None (sentiment: bad) | Self propose (sentiment: good) |
| ApeChain (L3, individual) | Self sequence (sentiment: good) | Fraud proofs (INT) (sentiment: bad) | External (DAC) (sentiment: bad) | None (sentiment: bad) | Self propose (sentiment: good) |
| ApeChain (L3, combined) | Self sequence (sentiment: good) | Fraud proofs (INT) (sentiment: bad) | External (DAC) (sentiment: bad) | None (sentiment: bad) | Self propose (sentiment: good) |

### L3 combined risks

The information below reflects combined L2 & L3 risks.

#### Sequencer failure

Self sequence (sentiment: good)

In the event of a sequencer failure, users can force transactions to be included in the project's chain by sending them to L1. There can be up to a 4d delay on this operation.

#### State validation

Fraud proofs (INT) (6d 8h challenge period; sentiment: bad)

No actor outside of the single Proposer can submit fraud proofs. Interactive proofs (INT) require multiple transactions over time to resolve. The challenge protocol can be subject to delay attacks. There is a 6d 8h challenge period.

#### Data availability

External (DAC) (sentiment: bad)

Proof construction relies fully on data that is NOT published onchain. There exists a Data Availability Committee (DAC) with a threshold of 5/7 that is tasked with protecting and supplying the data.

#### Exit window

None (sentiment: bad)

There is no window for users to exit in case of an unwanted upgrade since contracts are instantly upgradable.

#### Proposer failure

Self propose (sentiment: good)

Anyone can become a Proposer after 12d 17h of inactivity from the currently whitelisted Proposers.

## Stage

ApeChain is not even a Stage 0 project.

**Warning:** The requirement for available node software is under review.

### Stage 0

1 issue needs fixing.

- Met: The project self-identifies as a Validium or Optimium.
- Met: State roots are posted to Ethereum L1.
- Met: A complete and functional proof system (fraud or validity proofs) is deployed.
- Under review: A source-available node exists that can reconstruct the L2 state when DA is accessible. Please note that the ETHBEAT team has not verified the validity of the node source code.
- Issue: Fraud proof submission is not sufficiently decentralized.

### Stage 1

4 issues need fixing.

**Principle**

- Issue: Compromising ≥75% of the Security Council to push a malicious upgrade, or sequencer+DA-committee collusion to withhold data and finalize invalid state roots, should be the only ways (other than bugs) to steal funds or block withdrawals indefinitely.

**Guidelines**

- Met: Users are able to exit without the help of the permissioned operators, provided DA is accessible.
- Issue: Upgrades executed by actors with more centralized control than a Security Council provide less than 7d for users to exit if the permissioned operator is down or censoring.
- Issue: The Security Council is not properly set up.
- Issue: Not all program sources are public or not all program hashes can be independently regenerated.

[Learn more about Stages](https://ethbeat.org/stages).

Please keep in mind that these stages do not reflect project security, this is an opinionated assessment of project 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.

## Data availability

Set of parties responsible for signing and attesting to the availability of data.

### Risk analysis

#### Economic security

None (sentiment: bad)

There are no onchain assets at risk of being slashed in case of a data withholding attack, and the committee members are not publicly known.

#### Fraud detection

None (sentiment: bad)

There is no fraud detection mechanism in place. A data withholding attack can only be detected by nodes downloading the full data from the DA layer.

#### Committee security

5/7 (sentiment: bad)

The committee does not meet basic security standards, either due to insufficient size, lack of member diversity, or poorly defined threshold parameters. The system lacks an effective DA bridge and it is reliant on the assumption of an honest sequencer, creating significant risks to data integrity and availability.

#### Upgradeability

No delay (sentiment: bad)

There is no delay in the upgradeability of the bridge. Users have no time to exit the system before the bridge implementation update is completed.

#### Relayer failure

No mechanism (sentiment: bad)

The relayer role is permissioned, and the DA bridge does not have a Security Council or a governance mechanism to propose new relayers. In case of relayer failure, the DA bridge will halt and be unable to recover without the intervention of a centralized entity.

### Technology

#### Architecture
![Anytrust architecture](https://ethbeat.org/images/da-layer-technology/anytrust/architecture7.png#center)

The DAC uses a data availability solution built on the AnyTrust protocol. It is composed of the following components:
- **Sequencer Inbox**: Main entry point for the Sequencer submitting transaction batches.
- **Data Availability Committee (DAC)**: A group of members responsible for storing and providing data on demand.
- **Data Availability Certificate (DACert)**: A commitment ensuring that data blobs are available without needing full data posting on the L1 chain.

Committee members run servers that support APIs for storing and retrieving data blobs.
The Sequencer API allows the rollup Sequencer to submit data blobs for storage, while the REST API enables anyone to fetch data by hash.
When the Sequencer produces a data batch, it sends the batch along with an expiration time to Committee members, who store it and sign it.
Once enough signatures are collected, the Sequencer aggregates them into a valid DACert and posts it to the L1 chain inbox.
If the Sequencer fails to collect enough signatures, it falls back to posting the full data to the L1 chain as calldata.

A DACert includes a hash of the data block, an expiration time, and proof that the required threshold of Committee members have signed off on the data.
The proof consists of a hash of the Keyset used in signing, a bitmap indicating which members signed, and a BLS aggregated signature.
L2 nodes reading from the sequencer inbox verify the certificate’s validity by checking the number of signers, the aggregated signature, and that the expiration time is at least two weeks ahead of the L2 timestamp.
If the DACert is valid, it provides a proof that the corresponding data is available from honest committee members.

#### DA Bridge Architecture
![Anytrust bridge architecture](https://ethbeat.org/images/da-bridge-technology/anytrust/architectureL3.png#center)

The DA commitments are posted to the destination chain through the sequencer inbox, using the inbox as a DA bridge.
The DA commitment consists of Data Availability Certificate (DACert), including a hash of the data block, an expiration time, and a proof that the required threshold of Committee members have signed off on the data.
The sequencer distributes the data and collects signatures from Committee members offchain. Only the DACert is posted by the sequencer to the destination chain inbox (the DA bridge), achieving destination chain transaction ordering finality in a single onchain transaction.

**Risks**

- Funds can be lost if a malicious committee attests to an invalid data availability certificate.
- Funds can be lost if the bridge contract or its dependencies receive a malicious code upgrade. There is no delay on code upgrades.

**References**

- [Inside AnyTrust - Arbitrum Docs](https://docs.arbitrum.io/how-arbitrum-works/inside-anytrust)

## State validation

![A diagram of the state validation](https://ethbeat.org/static/images/state-validation/orbit.b691a319.png)

Updates to the system state can be proposed and challenged by a set of whitelisted validators. If a state root passes the challenge period, it is optimistically considered correct and made actionable for withdrawals.

### State root proposals

Whitelisted validators propose state roots as children of a previous state root. A state root can have multiple conflicting children. This structure forms a graph, and therefore, in the contracts, state roots are referred to as nodes. Each proposal requires a stake, currently set to 0.1 ETH, that can be slashed if the proposal is proven incorrect via a fraud proof. Stakes can be moved from one node to one of its children, either by calling `stakeOnExistingNode` or `stakeOnNewNode`. New nodes cannot be created faster than the minimum assertion period by the same validator, currently set to 15m. The oldest unconfirmed node can be confirmed if the challenge period has passed and there are no siblings, and rejected if the parent is not a confirmed node or if the challenge period has passed and no one is staked on it.

**Risks**

- Funds can be stolen if none of the whitelisted verifiers checks the published state. Fraud proofs assume at least one honest and able validator (CRITICAL).

**References**

- [How is fraud proven - Arbitrum documentation FAQ](https://docs.arbitrum.io/get-started/arbitrum-introduction)

### Challenges

A challenge can be started between two siblings, i.e. two different state roots that share the same parent, by calling the `startChallenge` function. Validators cannot be in more than one challenge at the same time, meaning that the protocol operates with [partial concurrency](https://medium.com/l2beat/fraud-proof-wars-b0cb4d0f452a). Since each challenge lasts 6d 8h, this implies that the protocol can be subject to [delay attacks](https://medium.com/offchainlabs/solutions-to-delay-attacks-on-rollups-434f9d05a07a), where a malicious actor can delay withdrawals as long as they are willing to pay the cost of losing their stakes. If the protocol is delayed attacked, the new stake requirement increases exponentially for each challenge period of delay. Challenges are played via a bisection game, where asserter and challenger play together to find the first instruction of disagreement. Such instruction is then executed onchain in the WASM OneStepProver contract to determine the winner, who then gets half of the stake of the loser. As said before, a state root is rejected only when no one left is staked on it. The protocol does not enforces valid bisections, meaning that actors can propose correct initial claim and then provide incorrect midpoints.

**References**

- [Fraud Proof Wars: Arbitrum Classic](https://medium.com/l2beat/fraud-proof-wars-b0cb4d0f452a)

### Program Hashes

#### ArbOS wasmModuleRoot Apechain

A commitment to the exact WASM binary version used for Orbit stack optimistic dispute games.

- Hash: `0x2dc824fed99dcdf659f2523ad68d1ec70bd5f08e3c533996be3a2d2b19813e83`
- Repository: code unknown
- Verification: unsuccessful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

##### Verification steps

The sources for this program are located in a private repository, shared with ETHBEAT to independently regenerate the wasm module root. This value is not reproducible by members of public, but we attest that it can be obtained from sources.

#### Apechain TEE Enclave hash

- Hash: `0x025b20bb8cd6aebf15f787050c19291014ec2ef70cf045f756c3a90d2a672373`
- Repository: code unknown
- Verification: unsuccessful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

#### Apechain TEE Enclave hash

- Hash: `0x583e7aa038d9dbd6ac02ff85270ad47c76b68899886f63563c59e7e1589d2145`
- Repository: code unknown
- Verification: not verified
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

#### Nitro TEE Verifer

Verifies correctness of a single TEE attestation for correctly running Arbitrum Nitro within a trusted enclave.

- Hash: `0x00643c7149cf335e7ec9d3f3301e69658a7f0ef2bc7546509c257ed8809f28e1`
- Repository: https://github.com/automata-network/aws-nitro-enclave-attestation/tree/8607619cc620a93d029a9569bccf752f341aad99/crates/sp1-methods/sp1-verifier
- Verification: successful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain), [Appchain](https://ethbeat.org/layer2s/projects/appchain), [Molten Network](https://ethbeat.org/layer2s/projects/molten)

##### Verification steps

Prepare:

1. Install sp1 toolchain: `curl -L https://sp1up.succinct.xyz/ | bash`
2. Make sure SP1 v6.1.0 is active: `sp1up -v 6.1.0` (must match the workspace `sp1-sdk = "^6.1.0"` dependency)
3. Install docker [https://docs.docker.com/get-docker/](https://docs.docker.com/get-docker/)

Verify:

1. Checkout the correct branch in [automata-network/aws-nitro-enclave-attestation](https://github.com/automata-network/aws-nitro-enclave-attestation/tree/feat/reproducible_build) repo: `git checkout feat/reproducible_build`. Commit hash should be `8607619cc620a93d029a9569bccf752f341aad99`.
2. Make sure docker is running by running `docker ps`.
3. From the repo root: `cargo clean -p sp1-methods` to clear any stale build artifacts.
4. From the repo root run: `REPRODUCIBLE_BUILD=docker cargo run --release -p nitro-attest-cli --no-default-features --features sp1 -- program-id --sp1`. The `REPRODUCIBLE_BUILD=docker` env var triggers the SP1 docker reproducible rebuild of `sp1-verifier` and `sp1-aggregator` ELFs (replacing `USE_DOCKER=1` used on older branches). The CLI then prints `Verifier ID`, `Verifier Proof ID`, and `Aggregator ID`.

#### Nitro TEE Aggregated Verifer

Verifies correctness of several aggregated TEE attestations for correctly running Arbitrum Nitro within a trusted enclave.

- Hash: `0x00294928e44f0cdc9c74848c4cafcdb29f733a3bc07408c240be3d5afe750b3e`
- Repository: https://github.com/automata-network/aws-nitro-enclave-attestation/tree/8607619cc620a93d029a9569bccf752f341aad99/crates/sp1-methods/sp1-aggregator
- Verification: successful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain), [Appchain](https://ethbeat.org/layer2s/projects/appchain), [Molten Network](https://ethbeat.org/layer2s/projects/molten)

##### Verification steps

Prepare:

1. Install sp1 toolchain: `curl -L https://sp1up.succinct.xyz/ | bash`
2. Make sure SP1 v6.1.0 is active: `sp1up -v 6.1.0` (must match the workspace `sp1-sdk = "^6.1.0"` dependency)
3. Install docker [https://docs.docker.com/get-docker/](https://docs.docker.com/get-docker/)

Verify:

1. Checkout the correct branch in [automata-network/aws-nitro-enclave-attestation](https://github.com/automata-network/aws-nitro-enclave-attestation/tree/feat/reproducible_build) repo: `git checkout feat/reproducible_build`. Commit hash should be `8607619cc620a93d029a9569bccf752f341aad99`.
2. Make sure docker is running by running `docker ps`.
3. From the repo root: `cargo clean -p sp1-methods` to clear any stale build artifacts.
4. From the repo root run: `REPRODUCIBLE_BUILD=docker cargo run --release -p nitro-attest-cli --no-default-features --features sp1 -- program-id --sp1`. The `REPRODUCIBLE_BUILD=docker` env var triggers the SP1 docker reproducible rebuild of `sp1-verifier` and `sp1-aggregator` ELFs (replacing `USE_DOCKER=1` used on older branches). The CLI then prints `Verifier ID`, `Verifier Proof ID`, and `Aggregator ID`.

## Upgrades & Governance

### Past upgrades

The metrics include upgrades on the currently used proxy contracts. Historical proxy contracts and changes of such are not included.

- Count of upgrades: 3
- Last upgrade: 1y ago
- Avg upgrade interval: 10mo 19d

- 2025-10-14 19:31 UTC, upgrade of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0xf2787805eb5c45529aacb68a446f51693fa2ffabbbe77585921d236a9b43d97a](https://arbiscan.io/tx/0xf2787805eb5c45529aacb68a446f51693fa2ffabbbe77585921d236a9b43d97a), implementations: [0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575](https://arbiscan.io/address/0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575#code) ([diff](https://disco.l2beat.com/diff/arb1:0x0DD7dA1805d207511bb3Edabe9352B9E316048bE/arb1:0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575))
- 2025-06-13 13:06 UTC, upgrade of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544](https://arbiscan.io/tx/0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544), implementations: [0x0DD7dA1805d207511bb3Edabe9352B9E316048bE](https://arbiscan.io/address/0x0DD7dA1805d207511bb3Edabe9352B9E316048bE#code) ([diff](https://disco.l2beat.com/diff/arb1:0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe/arb1:0x0DD7dA1805d207511bb3Edabe9352B9E316048bE))
- 2025-06-13 13:06 UTC, upgrade of [Inbox](https://arbiscan.io/address/0x1B98e4ED82Ee1a91A65a38C690e2266364064D15#code): transaction [0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544](https://arbiscan.io/tx/0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544), implementations: [0xFa76A234b41f932Fa769f92d85574e1BEEfE8218](https://arbiscan.io/address/0xFa76A234b41f932Fa769f92d85574e1BEEfE8218#code) ([diff](https://disco.l2beat.com/diff/arb1:0xCd26Db56B29e88b5394063aEA727DB1a03E961a7/arb1:0xFa76A234b41f932Fa769f92d85574e1BEEfE8218))
- 2024-08-28 16:45 UTC, deployment of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe](https://arbiscan.io/address/0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe#code)
- 2024-08-28 16:45 UTC, deployment of [Inbox](https://arbiscan.io/address/0x1B98e4ED82Ee1a91A65a38C690e2266364064D15#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xCd26Db56B29e88b5394063aEA727DB1a03E961a7](https://arbiscan.io/address/0xCd26Db56B29e88b5394063aEA727DB1a03E961a7#code)
- 2024-08-28 16:45 UTC, deployment of [RollupProxy](https://arbiscan.io/address/0x374de579AE15aD59eD0519aeAf1A23F348Df259c#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d](https://arbiscan.io/address/0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d#code), [0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4](https://arbiscan.io/address/0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4#code)
- 2024-08-28 16:45 UTC, deployment of [Bridge](https://arbiscan.io/address/0x6B71AFb4b7725227ab944c96FE018AB9dc0434b8#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x20B3C55fe4ecd989beB56E13b2A726110f0c3619](https://arbiscan.io/address/0x20B3C55fe4ecd989beB56E13b2A726110f0c3619#code)
- 2024-08-28 16:45 UTC, deployment of [ChallengeManager](https://arbiscan.io/address/0xAB2182C8c9a9d853Cf06A77967D2b3971A453ee1#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x6Feb471ce7D32ee16047F1A983ac4f592df96526](https://arbiscan.io/address/0x6Feb471ce7D32ee16047F1A983ac4f592df96526#code)
- 2024-08-28 16:45 UTC, deployment of [UpgradeExecutor](https://arbiscan.io/address/0xe032d15909e90f9A36901abB08944653e9E87d72#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786](https://arbiscan.io/address/0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786#code)
- 2024-08-28 16:45 UTC, deployment of [Outbox](https://arbiscan.io/address/0x4F405BA65291063d8A524c2bDf55d4e67405c2aF#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x4D92EE5cCA2A93b30549a6398C063861F18B6726](https://arbiscan.io/address/0x4D92EE5cCA2A93b30549a6398C063861F18B6726#code)
- 2024-08-28 16:45 UTC, deployment of [RollupEventInbox](https://arbiscan.io/address/0xf383814AE1eD316ed7d6FeA28810C77E8a15A49F#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96](https://arbiscan.io/address/0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96#code)

## Updates

Each date links the update on the HTML page, which also shows its contract diffs.

### [2026-10-27 15:08 UTC](https://ethbeat.org/layer2s/projects/apechain?update=e7b32daf) (high severity, 2 changes)

EspressoNitroTEEVerifier: 1 enclave hash and 1 signer added.

### [2026-10-20 10:09 UTC](https://ethbeat.org/layer2s/projects/apechain?update=125c2130) (1 change)

SequencerInbox `sequencerVersion` 0x00 → 0x88: batches are DAC certificates again since 2026-10-15.

### [2026-10-09 08:12 UTC](https://ethbeat.org/layer2s/projects/apechain?update=3155cbda) (1 change)

EspressoTEEVerifier owner Safe: member rotated.

### [2026-10-01 21:59 UTC](https://ethbeat.org/layer2s/projects/apechain?update=b43ed98f) (1 change)

SequencerInbox: since 2026-08-31 batches are posted as calldata on Arbitrum One instead of AnyTrust DAC certificates.

### [2026-08-10 11:02 UTC](https://ethbeat.org/layer2s/projects/apechain?update=5a25c5bb) (1 change)

SequencerInbox: the latest batch was posted as an AnyTrust DAC certificate rather than as data on the host chain.

### [2026-07-03 10:11 UTC](https://ethbeat.org/layer2s/projects/apechain?update=88cae8ff) (3 changes)

SequencerInbox `sequencerVersion` flipped `0x88` → `0x00`: latest batch posted as Ethereum calldata instead of a DAC certificate (AnyTrust fall-back). ApeChainMultisig dropped one signer; threshold 3/7 → 3/6.

### [2026-06-26 08:39 UTC](https://ethbeat.org/layer2s/projects/apechain?update=c39eceb9) (26 changes)

Removed SGX TEE verifier flow from tee attestation verification, leaving only Nitro.

Registered new wasm module root (ArbOS commitment) and valid TEE enclave hash. Both are not known from other depoloyments and are not verified.

Also, rotated one Apechain ms member and added two more.

### [2026-06-05 10:09 UTC](https://ethbeat.org/layer2s/projects/apechain?update=82c06f40) (high severity, 7 changes)

Switched to checking TEE attestations with zk in the style of Appchain. Appchain contracts resued (a slightly older version though): https://disco.l2beat.com/diff/eth:0x9E490ce0203d191Cae0ABF5614D561cC6fdc771f/arb1:0x9bE8dA826D2C6E6708372f0d056f57B97e6dB029, the only difference is that owner can change the TEE verifier contact.

### [2026-05-08 09:35 UTC](https://ethbeat.org/layer2s/projects/apechain?update=140387ab) (2 changes)

Shared SafeL2 (`0x6Dc61D9E...`) — signer `0x5582a8A4` removed. Threshold unchanged at 2; total signers 4 → 3 (50% → 67%). Same shared multisig change observed on `appchain` (same address on Ethereum), `molten`, `rari`.

### [2026-02-10 15:07 UTC](https://ethbeat.org/layer2s/projects/apechain?update=f0c9fc8a) (high severity, 4 changes)

Ownership of Espresso TEE verifier contracts (EspressoSGXTEEVerifier, EspressoTEEVerifier, EspressoNitroTEEVerifier) transferred from EOA to new SafeL2 multisig.

### [2025-12-03 08:34 UTC](https://ethbeat.org/layer2s/projects/apechain?update=438bbd07) (high severity, 5 changes)

Reintroduce known standard EspressoNitroTEEVerifier.

### [2025-11-24 08:51 UTC](https://ethbeat.org/layer2s/projects/apechain?update=48b558be) (high severity, 5 changes)

upgrade: espressoNitroTEEVerifier is bypassed with `return True` and `onlyOwner` funcs. The new contract can be used to spoof any signature.
https://disco.l2beat.com/diff/arb1:0xC17cd192bd0aF90a0a5c6021ee038E9223bf390C/arb1:0x27d3F7fB1F155F81E633f4E29b2322b7ffafe8e4

### [2025-11-18 11:38 UTC](https://ethbeat.org/layer2s/projects/apechain?update=85a6fb0f) (1 change)

New registered AWS TEE signer.

### [2025-11-05 22:23 UTC](https://ethbeat.org/layer2s/projects/apechain?update=db9f688d) (2 changes)

New registered AWS TEE signers.

### [2025-10-15 14:24 UTC](https://ethbeat.org/layer2s/projects/apechain?update=65f832b4) (high severity, 18 changes)

Apechain now uses Espresso sequencer.

### [2025-07-14 13:11 UTC](https://ethbeat.org/layer2s/projects/apechain?update=262a3d1c) (16 changes)

Discovery rerun on the same block number with only config-related changes.

### [2025-06-18 11:54 UTC](https://ethbeat.org/layer2s/projects/apechain?update=1dd6bed9) (high severity, 14 changes)

late upgrade to standard orbit implementations.

### [2024-10-21 08:58 UTC](https://ethbeat.org/layer2s/projects/apechain?update=9a647e2e) (18 changes)

Standard Orbit stack AnyTrust optimium with APE gas token and max supply premint (bridged via LayerZero) on L3.

## Operator

The section considers only the L3 properties. For more details please refer to [Arbitrum One](https://ethbeat.org/layer2s/projects/arbitrum)

### The system has a centralized sequencer

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

**Risks**

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

**References**

- [Sequencer - Arbitrum documentation](https://docs.arbitrum.io/how-arbitrum-works/inside-arbitrum-nitro#the-sequencer)

### 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 smart contract on the host chain directly. After a delay of 3d in which a Sequencer has failed to include a transaction that was directly posted to the smart contract, it can be forcefully included by anyone on the host chain, which finalizes its ordering.

**References**

- [SequencerInbox.sol - source code, forceInclusion function](https://arbiscan.io/address/0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575#code)
- [Sequencer Isn't Doing Its Job - Arbitrum documentation](https://docs.arbitrum.io/how-arbitrum-works/sequencer#unhappyuncommon-case-sequencer-isnt-doing-its-job)

## Sequencing

### Delayed forced transactions

To force transactions from the host chain, users must first enqueue "delayed" messages in the "delayed" inbox of the Bridge contract. Only authorized Inboxes are allowed to enqueue delayed messages, and the so-called Inbox contract is the one used as the entry point by calling the `sendMessage` or `sendMessageFromOrigin` functions. If the centralized sequencer doesn't process the request within some time bound, users can call the `forceInclusion` function on the SequencerInbox contract to include the message in the canonical chain. The time bound is hardcoded to be 3d.

## Withdrawals

The section considers only the L3 properties. For more details please refer to [Arbitrum One](https://ethbeat.org/layer2s/projects/arbitrum)

### 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 usually takes several days to complete.

**References**

- [Transaction lifecycle - Arbitrum documentation](https://developer.offchainlabs.com/tx-lifecycle)
- [L2 to L1 Messages - Arbitrum documentation](https://docs.arbitrum.io/how-arbitrum-works/deep-dives/l2-to-l1-messaging)
- [Mainnet for everyone - Arbitrum Blog](https://offchain.medium.com/mainnet-for-everyone-27ce0f67c85e)

### Autonomous exit

Users can (eventually) exit the system by pushing the transaction on L1 and providing the corresponding state root. The only way to prevent such withdrawal is via an upgrade.

## Other considerations

### EVM compatible smart contracts are supported

Arbitrum One uses Nitro technology that allows running fraud proofs by executing EVM code on top of WASM.

**References**

- [Inside Arbitrum Nitro](https://developer.offchainlabs.com/inside-arbitrum-nitro/)

## Permissions

Explore these contracts and permissions in Disco, ETHBEAT's contract explorer: https://disco.l2beat.com/ui/p/apechain

### Arbitrum One

#### Actors

##### ApeChainMultisig

Addresses: [0x2B1FbeE3c7D278bFD9E179893FF304fE49FA7DDF](https://arbiscan.io/address/0x2B1FbeE3c7D278bFD9E179893FF304fE49FA7DDF)

A Multisig with 3/6 threshold.
- Can upgrade **with no delay**
  - Inbox [via: UpgradeExecutor → ProxyAdmin]
  - RollupProxy [via: UpgradeExecutor]
  - Outbox [via: UpgradeExecutor → ProxyAdmin]
  - Bridge [via: UpgradeExecutor → ProxyAdmin]
  - ChallengeManager [via: UpgradeExecutor → ProxyAdmin]
  - UpgradeExecutor [via: UpgradeExecutor → ProxyAdmin]
  - SequencerInbox [via: UpgradeExecutor → ProxyAdmin]
  - RollupEventInbox [via: UpgradeExecutor → ProxyAdmin]
- Can interact with RollupProxy
  - Pause and unpause and set important roles and parameters in the system contracts: Can delegate Sequencer management to a BatchPosterManager address, manage data availability, DACs and the fastConfirmer role, set the Sequencer-only window, introduce an allowList to the bridge and whitelist Inboxes/Outboxes [via: UpgradeExecutor]

Participants (6): [0xe2d8761a2a87b06413e39D08C31b683cDD4dF4a4](https://arbiscan.io/address/0xe2d8761a2a87b06413e39D08C31b683cDD4dF4a4), [0x6c447467FED500eEa91309c0b0c302Aa9763412d](https://arbiscan.io/address/0x6c447467FED500eEa91309c0b0c302Aa9763412d), [0xd125c9222160C308EdC5Cf642573Ca8a14D9d33c](https://arbiscan.io/address/0xd125c9222160C308EdC5Cf642573Ca8a14D9d33c), [0xbc1Cb7133f080eB61262dafB77788B95e208B77F](https://arbiscan.io/address/0xbc1Cb7133f080eB61262dafB77788B95e208B77F), [0x8765bb776b00A14198025283988c23F72D330E2a](https://arbiscan.io/address/0x8765bb776b00A14198025283988c23F72D330E2a), [0x65c10dD3d50B10D0E1Bb459675b03367B1b52eD1](https://arbiscan.io/address/0x65c10dD3d50B10D0E1Bb459675b03367B1b52eD1)

##### SafeL2

Addresses: [0x6Dc61D9E366697979f69D89a154f2F8cd2F11dA5](https://arbiscan.io/address/0x6Dc61D9E366697979f69D89a154f2F8cd2F11dA5)

A Multisig with 2/3 threshold.
- Can interact with EspressoTEEVerifier
  - add, remove or disable supported enclave hashes
  - change the TEE verifier contract

Participants (3): [0xb9e40b6E60CcD5361774cf4D36d1fCe66B649b63](https://arbiscan.io/address/0xb9e40b6E60CcD5361774cf4D36d1fCe66B649b63), [0x5E768dd03BD821703ef825e057434De85913EEAC](https://arbiscan.io/address/0x5E768dd03BD821703ef825e057434De85913EEAC), [0xd16384742f34511ade0555bC6312A284Ab1339bA](https://arbiscan.io/address/0xd16384742f34511ade0555bC6312A284Ab1339bA)

##### EspressoTEEVerifier

Addresses: [0x9440e52851706A261965c128A6CB3b5C455177Fb](https://arbiscan.io/address/0x9440e52851706A261965c128A6CB3b5C455177Fb)

TEE gateway contract that can be used to 1) register signers that were generated inside a TEE and 2) verify the signatures of such signers. It supports AWS Nitro TEEs through modular contracts.
- Can interact with EspressoNitroTEEVerifier
  - set the enclaveHash (hash of enclave's code and initial data) and delete all registered signers

##### EOA 1

Addresses: [0x3918b6ecc471211a942B0A904fbFb36302348f6B](https://arbiscan.io/address/0x3918b6ecc471211a942B0A904fbFb36302348f6B)

- Can interact with SequencerInbox
  - Add/remove batchPosters (Sequencers)
  - Can submit transaction batches or commitments to the SequencerInbox contract on the host chain

##### EOA 2

Addresses: [0xAcB7D670bb95144B88a5Cd1883B87bC5021FD10a](https://arbiscan.io/address/0xAcB7D670bb95144B88a5Cd1883B87bC5021FD10a)

- Can interact with RollupProxy
  - Can propose new state roots (called nodes) and challenge state roots on the host chain

##### EOA 3

Addresses: [0xba1E3EFfD2DD8CEb7054FEfb0cee8C4300D82C1a](https://arbiscan.io/address/0xba1E3EFfD2DD8CEb7054FEfb0cee8C4300D82C1a)

- Can interact with NitroEnclaveVerifier
  - set the root certificate, add/remove ZK verifier routes, update verifier and aggregator program IDs, and change the ZK coprocessor configuration

##### EOA 4

Addresses: [0xFb259F30199B4f4AB9c9a26019f83b195837075E](https://arbiscan.io/address/0xFb259F30199B4f4AB9c9a26019f83b195837075E)

- Can upgrade **with no delay**
  - EspressoTEEVerifier [via: ProxyAdmin]

## Smart contracts

![A diagram of the smart contract architecture](https://ethbeat.org/static/images/architecture/orbit-optimium.5e9f33fb.png)

Explore these contracts and permissions in Disco, ETHBEAT's contract explorer: https://disco.l2beat.com/ui/p/apechain

### Arbitrum One

#### RollupProxy

Addresses: [0x374de579AE15aD59eD0519aeAf1A23F348Df259c](https://arbiscan.io/address/0x374de579AE15aD59eD0519aeAf1A23F348Df259c#code), [0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d](https://arbiscan.io/address/0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d#code) (Implementation #1 (Upgradable)), [0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4](https://arbiscan.io/address/0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4#code) (Implementation #2 (Upgradable)), [0xe032d15909e90f9A36901abB08944653e9E87d72](https://arbiscan.io/address/0xe032d15909e90f9A36901abB08944653e9E87d72#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [RollupProxy](https://arbiscan.io/address/0x374de579AE15aD59eD0519aeAf1A23F348Df259c#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d](https://arbiscan.io/address/0x2733fc1C97f6562466E9B29D64bCc6dC833cC88d#code), [0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4](https://arbiscan.io/address/0x230cf5A0FE4cC58deaf8a147A42ACF3f3C20A8C4#code)

Central contract for the project's configuration like its execution logic hash (`wasmModuleRoot`) and addresses of the other system contracts. Entry point for Proposers creating new Rollup Nodes (state commitments) and Challengers submitting fraud proofs (In the Orbit stack, these two roles are both held by the Validators).
- Roles:
  - **admin**: UpgradeExecutor; ultimately ApeChainMultisig
  - **owner**: UpgradeExecutor; ultimately ApeChainMultisig
  - **validators**: EOA 2

Can be upgraded by: ApeChainMultisig with no delay

#### Bridge (escrow)

Addresses: [0x6B71AFb4b7725227ab944c96FE018AB9dc0434b8](https://arbiscan.io/address/0x6B71AFb4b7725227ab944c96FE018AB9dc0434b8#code), [0x20B3C55fe4ecd989beB56E13b2A726110f0c3619](https://arbiscan.io/address/0x20B3C55fe4ecd989beB56E13b2A726110f0c3619#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [Bridge](https://arbiscan.io/address/0x6B71AFb4b7725227ab944c96FE018AB9dc0434b8#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x20B3C55fe4ecd989beB56E13b2A726110f0c3619](https://arbiscan.io/address/0x20B3C55fe4ecd989beB56E13b2A726110f0c3619#code)

Escrow contract for the project's gas token (can be different from ETH). Keeps a list of allowed Inboxes and Outboxes for canonical bridge messaging.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig

The following tokens are included in the value secured calculation: APE

Can be upgraded by: ApeChainMultisig with no delay

#### ChallengeManager

Addresses: [0xAB2182C8c9a9d853Cf06A77967D2b3971A453ee1](https://arbiscan.io/address/0xAB2182C8c9a9d853Cf06A77967D2b3971A453ee1#code), [0x6Feb471ce7D32ee16047F1A983ac4f592df96526](https://arbiscan.io/address/0x6Feb471ce7D32ee16047F1A983ac4f592df96526#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [ChallengeManager](https://arbiscan.io/address/0xAB2182C8c9a9d853Cf06A77967D2b3971A453ee1#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x6Feb471ce7D32ee16047F1A983ac4f592df96526](https://arbiscan.io/address/0x6Feb471ce7D32ee16047F1A983ac4f592df96526#code)

Contract that allows challenging state roots. Can be called through the RollupProxy by Validators or the UpgradeExecutor.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig

Can be upgraded by: ApeChainMultisig with no delay

#### SequencerInbox

Addresses: [0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code), [0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575](https://arbiscan.io/address/0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: 2, Last upgrade: 1y ago, Avg upgrade interval: 8mo 25d)

- 2025-10-14 19:31 UTC, upgrade of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0xf2787805eb5c45529aacb68a446f51693fa2ffabbbe77585921d236a9b43d97a](https://arbiscan.io/tx/0xf2787805eb5c45529aacb68a446f51693fa2ffabbbe77585921d236a9b43d97a), implementations: [0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575](https://arbiscan.io/address/0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575#code) ([diff](https://disco.l2beat.com/diff/arb1:0x0DD7dA1805d207511bb3Edabe9352B9E316048bE/arb1:0xCfAfB803EF1FEc576138Cebc79Ad41Aa6760C575))
- 2025-06-13 13:06 UTC, upgrade of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544](https://arbiscan.io/tx/0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544), implementations: [0x0DD7dA1805d207511bb3Edabe9352B9E316048bE](https://arbiscan.io/address/0x0DD7dA1805d207511bb3Edabe9352B9E316048bE#code) ([diff](https://disco.l2beat.com/diff/arb1:0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe/arb1:0x0DD7dA1805d207511bb3Edabe9352B9E316048bE))
- 2024-08-28 16:45 UTC, deployment of [SequencerInbox](https://arbiscan.io/address/0xE6a92Ae29E24C343eE66A2B3D3ECB783d65E4a3C#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe](https://arbiscan.io/address/0x51120FA6D564A70E9F80874c0a55A4ee0c7396Fe#code)

The Espresso TEE sequencer (registered in this contract) can submit transaction batches or commitments here.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig
  - **batchPosterManager**: EOA 1
  - **batchPosters**: EOA 1

Can be upgraded by: ApeChainMultisig with no delay

#### UpgradeExecutor

Addresses: [0xe032d15909e90f9A36901abB08944653e9E87d72](https://arbiscan.io/address/0xe032d15909e90f9A36901abB08944653e9E87d72#code), [0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786](https://arbiscan.io/address/0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [UpgradeExecutor](https://arbiscan.io/address/0xe032d15909e90f9A36901abB08944653e9E87d72#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786](https://arbiscan.io/address/0xdbE68E9e47c4AC96Ab1300902b4B87A7E6470786#code)

Central contract defining the access control permissions for upgrading the system contract implementations.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig
  - **executors**: ApeChainMultisig

Can be upgraded by: ApeChainMultisig with no delay

#### Inbox

Addresses: [0x1B98e4ED82Ee1a91A65a38C690e2266364064D15](https://arbiscan.io/address/0x1B98e4ED82Ee1a91A65a38C690e2266364064D15#code), [0xFa76A234b41f932Fa769f92d85574e1BEEfE8218](https://arbiscan.io/address/0xFa76A234b41f932Fa769f92d85574e1BEEfE8218#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: 1, Last upgrade: 1y 4mo ago, Avg upgrade interval: 1y 1mo)

- 2025-06-13 13:06 UTC, upgrade of [Inbox](https://arbiscan.io/address/0x1B98e4ED82Ee1a91A65a38C690e2266364064D15#code): transaction [0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544](https://arbiscan.io/tx/0xe385aeb814e7282eac24484389ea3b1f4e6b612a750b25b547bacc5dffb70544), implementations: [0xFa76A234b41f932Fa769f92d85574e1BEEfE8218](https://arbiscan.io/address/0xFa76A234b41f932Fa769f92d85574e1BEEfE8218#code) ([diff](https://disco.l2beat.com/diff/arb1:0xCd26Db56B29e88b5394063aEA727DB1a03E961a7/arb1:0xFa76A234b41f932Fa769f92d85574e1BEEfE8218))
- 2024-08-28 16:45 UTC, deployment of [Inbox](https://arbiscan.io/address/0x1B98e4ED82Ee1a91A65a38C690e2266364064D15#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xCd26Db56B29e88b5394063aEA727DB1a03E961a7](https://arbiscan.io/address/0xCd26Db56B29e88b5394063aEA727DB1a03E961a7#code)

Facilitates sending L1 to L2 messages like depositing ETH, but does not escrow funds.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig

Can be upgraded by: ApeChainMultisig with no delay

#### Outbox

Addresses: [0x4F405BA65291063d8A524c2bDf55d4e67405c2aF](https://arbiscan.io/address/0x4F405BA65291063d8A524c2bDf55d4e67405c2aF#code), [0x4D92EE5cCA2A93b30549a6398C063861F18B6726](https://arbiscan.io/address/0x4D92EE5cCA2A93b30549a6398C063861F18B6726#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [Outbox](https://arbiscan.io/address/0x4F405BA65291063d8A524c2bDf55d4e67405c2aF#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0x4D92EE5cCA2A93b30549a6398C063861F18B6726](https://arbiscan.io/address/0x4D92EE5cCA2A93b30549a6398C063861F18B6726#code)

Facilitates L2 to L1 contract calls: Messages initiated from L2 (for example withdrawal messages) eventually resolve in execution on L1.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig

Can be upgraded by: ApeChainMultisig with no delay

#### NitroEnclaveVerifier

Addresses: [0x1b467761E7a125381c4f654e11B397023Fc53DD8](https://arbiscan.io/address/0x1b467761E7a125381c4f654e11B397023Fc53DD8#code)

ZK-backed verifier for AWS Nitro enclave attestations. Verifies ZK proofs (RiscZero, Succinct SP1 or Pico) that attest AWS Nitro cert chain validation was executed correctly off-chain.
- Roles:
  - **owner**: EOA 3

#### ProxyAdmin (0x1E5f…b507)

Addresses: [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code)

- Roles:
  - **owner**: UpgradeExecutor

#### OneStepProverHostIo

Addresses: [0x4aBF0E8C011142bAb19ff3C921880B71E68150Ca](https://arbiscan.io/address/0x4aBF0E8C011142bAb19ff3C921880B71E68150Ca#code)

One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

#### OneStepProverMemory

Addresses: [0x550B7B23Ed78BA25B3aBCBb290ADf1190aC28E19](https://arbiscan.io/address/0x550B7B23Ed78BA25B3aBCBb290ADf1190aC28E19#code)

One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

#### OneStepProverMath

Addresses: [0x8A4ed18B4d31bCeA908B0f96B4347a9F99e816b3](https://arbiscan.io/address/0x8A4ed18B4d31bCeA908B0f96B4347a9F99e816b3#code)

One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

#### ProxyAdmin (0x927d…0870)

Addresses: [0x927dCF5D08795eEFd7C2bEC89777CFCD67950870](https://arbiscan.io/address/0x927dCF5D08795eEFd7C2bEC89777CFCD67950870#code)

- Roles:
  - **owner**: EOA 4

#### OneStepProver0

Addresses: [0xa301f8EdD4Cdf10553b6aB39d9724c56d7ab582F](https://arbiscan.io/address/0xa301f8EdD4Cdf10553b6aB39d9724c56d7ab582F#code)

One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

#### OneStepProofEntry

Addresses: [0xa3180c7a17dd46DEf808477093592D8231e024a8](https://arbiscan.io/address/0xa3180c7a17dd46DEf808477093592D8231e024a8#code)

One of the modular contracts used for the last step of a fraud proof, which is simulated inside a WASM virtual machine.

#### ValidatorUtils

Addresses: [0xaB36aec5517C346D21b9C19429BAA5aa87D17fCa](https://arbiscan.io/address/0xaB36aec5517C346D21b9C19429BAA5aa87D17fCa#code)

This contract implements view only utilities for validators.

#### EspressoNitroTEEVerifier

Addresses: [0xBA7E3C18A16FfD8062047422c63027459105BB35](https://arbiscan.io/address/0xBA7E3C18A16FfD8062047422c63027459105BB35#code)

Verifies attestations of an AWS Nitro TEE.
Note: currently only Succinct proofs are used.
- Roles:
  - **teeVerifier**: EspressoTEEVerifier

#### SP1Verifier

Addresses: [0xD9d5C8456a168Dd25561064F47bF116111131B1D](https://arbiscan.io/address/0xD9d5C8456a168Dd25561064F47bF116111131B1D#code)

Verifier contract for SP1 proofs (v6.1.0).

#### RollupEventInbox

Addresses: [0xf383814AE1eD316ed7d6FeA28810C77E8a15A49F](https://arbiscan.io/address/0xf383814AE1eD316ed7d6FeA28810C77E8a15A49F#code), [0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96](https://arbiscan.io/address/0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96#code) (Implementation (Upgradable)), [0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507](https://arbiscan.io/address/0x1E5f8ff72895aEa53DD62b590dA51E92dC75b507#code) (Admin)

**Past upgrades** (Count of upgrades: No upgrades, Last upgrade: N/A, Avg upgrade interval: N/A)

- 2024-08-28 16:45 UTC, deployment of [RollupEventInbox](https://arbiscan.io/address/0xf383814AE1eD316ed7d6FeA28810C77E8a15A49F#code): transaction [0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5](https://arbiscan.io/tx/0x0d8fd55271d42815ae9dcd9820e29d18690b3a49a3cbad17308afa6431334aa5), implementations: [0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96](https://arbiscan.io/address/0xF088dccfD7d39b24Ce0D4c91a4fEC3F56e3DBC96#code)

Helper contract sending configuration data over the bridge during the systems initialization.
- Roles:
  - **admin**: ProxyAdmin; ultimately ApeChainMultisig

Can be upgraded by: ApeChainMultisig with no delay

The current deployment carries some associated risks:

- Funds can be stolen if a contract receives a malicious code upgrade. There is no delay on code upgrades (CRITICAL).

### Program Hashes

#### ArbOS wasmModuleRoot Apechain

A commitment to the exact WASM binary version used for Orbit stack optimistic dispute games.

- Hash: `0x2dc824fed99dcdf659f2523ad68d1ec70bd5f08e3c533996be3a2d2b19813e83`
- Repository: code unknown
- Verification: unsuccessful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

##### Verification steps

The sources for this program are located in a private repository, shared with ETHBEAT to independently regenerate the wasm module root. This value is not reproducible by members of public, but we attest that it can be obtained from sources.

#### Apechain TEE Enclave hash

- Hash: `0x025b20bb8cd6aebf15f787050c19291014ec2ef70cf045f756c3a90d2a672373`
- Repository: code unknown
- Verification: unsuccessful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

#### Apechain TEE Enclave hash

- Hash: `0x583e7aa038d9dbd6ac02ff85270ad47c76b68899886f63563c59e7e1589d2145`
- Repository: code unknown
- Verification: not verified
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain)

#### Nitro TEE Verifer

Verifies correctness of a single TEE attestation for correctly running Arbitrum Nitro within a trusted enclave.

- Hash: `0x00643c7149cf335e7ec9d3f3301e69658a7f0ef2bc7546509c257ed8809f28e1`
- Repository: https://github.com/automata-network/aws-nitro-enclave-attestation/tree/8607619cc620a93d029a9569bccf752f341aad99/crates/sp1-methods/sp1-verifier
- Verification: successful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain), [Appchain](https://ethbeat.org/layer2s/projects/appchain), [Molten Network](https://ethbeat.org/layer2s/projects/molten)

##### Verification steps

Prepare:

1. Install sp1 toolchain: `curl -L https://sp1up.succinct.xyz/ | bash`
2. Make sure SP1 v6.1.0 is active: `sp1up -v 6.1.0` (must match the workspace `sp1-sdk = "^6.1.0"` dependency)
3. Install docker [https://docs.docker.com/get-docker/](https://docs.docker.com/get-docker/)

Verify:

1. Checkout the correct branch in [automata-network/aws-nitro-enclave-attestation](https://github.com/automata-network/aws-nitro-enclave-attestation/tree/feat/reproducible_build) repo: `git checkout feat/reproducible_build`. Commit hash should be `8607619cc620a93d029a9569bccf752f341aad99`.
2. Make sure docker is running by running `docker ps`.
3. From the repo root: `cargo clean -p sp1-methods` to clear any stale build artifacts.
4. From the repo root run: `REPRODUCIBLE_BUILD=docker cargo run --release -p nitro-attest-cli --no-default-features --features sp1 -- program-id --sp1`. The `REPRODUCIBLE_BUILD=docker` env var triggers the SP1 docker reproducible rebuild of `sp1-verifier` and `sp1-aggregator` ELFs (replacing `USE_DOCKER=1` used on older branches). The CLI then prints `Verifier ID`, `Verifier Proof ID`, and `Aggregator ID`.

#### Nitro TEE Aggregated Verifer

Verifies correctness of several aggregated TEE attestations for correctly running Arbitrum Nitro within a trusted enclave.

- Hash: `0x00294928e44f0cdc9c74848c4cafcdb29f733a3bc07408c240be3d5afe750b3e`
- Repository: https://github.com/automata-network/aws-nitro-enclave-attestation/tree/8607619cc620a93d029a9569bccf752f341aad99/crates/sp1-methods/sp1-aggregator
- Verification: successful
- Used in: [ApeChain](https://ethbeat.org/layer2s/projects/apechain), [Appchain](https://ethbeat.org/layer2s/projects/appchain), [Molten Network](https://ethbeat.org/layer2s/projects/molten)

##### Verification steps

Prepare:

1. Install sp1 toolchain: `curl -L https://sp1up.succinct.xyz/ | bash`
2. Make sure SP1 v6.1.0 is active: `sp1up -v 6.1.0` (must match the workspace `sp1-sdk = "^6.1.0"` dependency)
3. Install docker [https://docs.docker.com/get-docker/](https://docs.docker.com/get-docker/)

Verify:

1. Checkout the correct branch in [automata-network/aws-nitro-enclave-attestation](https://github.com/automata-network/aws-nitro-enclave-attestation/tree/feat/reproducible_build) repo: `git checkout feat/reproducible_build`. Commit hash should be `8607619cc620a93d029a9569bccf752f341aad99`.
2. Make sure docker is running by running `docker ps`.
3. From the repo root: `cargo clean -p sp1-methods` to clear any stale build artifacts.
4. From the repo root run: `REPRODUCIBLE_BUILD=docker cargo run --release -p nitro-attest-cli --no-default-features --features sp1 -- program-id --sp1`. The `REPRODUCIBLE_BUILD=docker` env var triggers the SP1 docker reproducible rebuild of `sp1-verifier` and `sp1-aggregator` ELFs (replacing `USE_DOCKER=1` used on older branches). The CLI then prints `Verifier ID`, `Verifier Proof ID`, and `Aggregator ID`.