# Arbitrum

> LOPW on Arbitrum through the EVM binding: chain ids and CAIP-2 ids for Arbitrum Sepolia and Arbitrum One, native USDC addresses, explorers, the Chainlink oracle note, and the LOPW contract addresses or the deployment status for each network.

*LOPW documentation · Networks.* Canonical page: https://lopw.com/docs/networks/arbitrum.html · This Markdown twin: https://lopw.com/docs/networks/arbitrum.md · Index of all pages: https://lopw.com/llms.txt · Everything in one file: https://lopw.com/llms-full.txt

Arbitrum runs LOPW through the shared [EVM binding](https://lopw.com/docs/networks/evm.html): Solidity contracts, EIP-712 typed data signed with secp256k1, native USDC with 6 decimals, Chainlink feeds for P6 and x402 `exact` with EIP-3009. Arbitrum One and Arbitrum Sepolia: an optimistic rollup with native USDC and Chainlink feeds; the same EVM binding applies unchanged.

**EVM binding**

## At a glance

| Item | Arbitrum Sepolia | Arbitrum One |
| --- | --- | --- |
| Network name (API paths) | `arbitrum-sepolia` | `arbitrum` |
| CAIP-2 | `eip155:421614` | `eip155:42161` |
| Chain id | 421614 | 42161 |
| USDC (native, 6 decimals) | [0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d](https://sepolia.arbiscan.io/address/0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d) | [0xaf88d065e77c8cC2239327C5EDb3A432268e5831](https://arbiscan.io/address/0xaf88d065e77c8cC2239327C5EDb3A432268e5831) |
| Explorer | [sepolia.arbiscan.io](https://sepolia.arbiscan.io) | [arbiscan.io](https://arbiscan.io) |
| P6 oracle | Chainlink feed, verified on-chain at deployment | Chainlink feed, verified on-chain at deployment |
| LOPW deployment | None published | None published |

## LOPW contracts

### Arbitrum Sepolia

Not deployed No LOPW deployment is published on this network yet.

### Arbitrum One

Not deployed No LOPW deployment is published on this network yet.

## Oracle note

P6 terms on Arbitrum name a Chainlink `AggregatorV3Interface` feed and its pair label as `bytes32`. The seller cites the `roundId` it used; the validator reads `getRoundData(roundId)` on-chain, applies `max_oracle_age` to the round’s `updatedAt`, and proves a breach with the exact integer deviation test. Every feed address is verified on-chain (`description()`, `decimals()`) before use and recorded in `deployments/.json`.

## What is identical to every other EVM network

- The Solidity contracts, their functions, errors and events.
- The EIP-712 type strings and the domain `LOPW` / `1`; only `chainId` and `verifyingContract` change.
- The wire form: 0x-hex ABI encoding of `SignedOffer` and `SignedReceipt`.
- USDC with 6 decimals as stake and payment token; x402 `exact` with EIP-3009.
- Indexing after `EVM_CONFIRMATIONS` confirmations, writing the same `events`, `services` and `claims` rows with `network` set to the names above.

## For agents

> **For agents**
>
> | Item | Value |
> | --- | --- |
> | Network name in API paths | `arbitrum-sepolia` (Arbitrum Sepolia), `arbitrum` (Arbitrum One); served once a LOPW deployment is published for the network |
> | CAIP-2 id | `eip155:421614`, `eip155:42161` |
> | Wire encoding of `extensions.lopw` | 0x-hex ABI encoding of `SignedOffer` (`info.offer`) and `SignedReceipt` (`receipt`); schemas [offer-evm.json](https://lopw.com/docs/schemas/offer-evm.json) and [receipt-evm.json](https://lopw.com/docs/schemas/receipt-evm.json) |
> | Explorer | `https://sepolia.arbiscan.io/tx/{hash}`, `https://sepolia.arbiscan.io/address/{address}` |
> | USDC | `0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d` (Arbitrum Sepolia), `0xaf88d065e77c8cC2239327C5EDb3A432268e5831` (Arbitrum One) |

- [EVM binding](https://lopw.com/docs/networks/evm.html): Types, EIP-712 hashing, contracts, P6 with Chainlink, x402 with EIP-3009, SDK.
- [All networks](https://lopw.com/docs/networks/): Stellar as the reference binding, the EVM networks, and the planned Solana binding.