[eltontay-circle]

Adds Arc (chain 5042) and Arc Testnet (chain 5042002) to Splits Lite, with USDC and EURC in the token list. It follows the README process for new tokens and chains.

Before merging: Splits v2 needs to be deployed on Arc, and @0xsplits/splits-kit needs a release that includes Arc. Until then the SDK rejects actions on Arc; other chains are unaffected. After that release, this PR only needs the splits-kit bump, plus Arc enabled on the splits-lite Alchemy app for mainnet.

Changes

• src/constants/chains.ts: adds arc and arcTestnet.
  • Mainnet RPC uses Alchemy (arc-mainnet.g.alchemy.com), like the other chains. Arc's docs list Alchemy for mainnet only, so Arc Testnet uses Circle's public RPC (rpc.testnet.arc.io), the same way Plume uses a public RPC.
  • Mainnet sets Multicall3 (0xcA11bde05977b3631167028862bE2a173976CA11, deployed on Arc) the same way Tempo does, because viem 2.56.5 in the lockfile ships arc without it. viem 2.56.6 and later include it.
• src/constants/erc20.ts: USDC and EURC on both networks.
• public/chain-icons/arc.svg: the Arc mark from Arc's official logo.

Chain details

	Arc	Arc Testnet
Chain ID	5042	5042002
Public RPC	https://rpc.mainnet.arc.io	https://rpc.testnet.arc.io
Explorer	https://explorer.arc.io	https://explorer.testnet.arc.io
Docs	https://docs.arc.io	https://docs.arc.io

README chain requirements, checked on both networks:

• CreateX: deployed at 0xba5Ed099633D3B313e4D5F7bdc1305d3c28ba5Ed, bytecode identical to Ethereum's. The CREATE2 deployer at 0x4e59b44847b379578588920cA78FbF26c0B4956C is also present.
• EVM: Arc targets the Osaka fork, which includes Shanghai, and PUSH0 was tested with eth_call. Differences from Ethereum are listed in Arc's EVM differences.
• viem: includes arc and arcTestnet.
• Deployer gas: funding transactions for 0x60C65c9a8674DA22e89C7d09e839908B9f0ecC3a on both networks will be added here.

Tokens

Token	Arc	Arc Testnet	Decimals
USDC	0x3600000000000000000000000000000000000000	0x3600000000000000000000000000000000000000	6
EURC	0xbEf5f6d51CB62b58e6A8f77868681825C6fe21c1	0x89B50855Aa3bE2F677cD6303Cec089B5F319D72a	6

• USDC: https://www.circle.com/usdc · CoinGecko: https://www.coingecko.com/en/coins/usdc
• EURC: https://www.circle.com/eurc · CoinGecko: https://www.coingecko.com/en/coins/euro-coin
• Official addresses: https://docs.arc.io/arc/references/contract-addresses

Arc-specific notes

• USDC is Arc's native gas token. The native balance uses 18 decimals, and the ERC-20 interface at 0x3600…0000 uses 6 decimals over the same balance. Arc's docs recommend that apps "rely solely on the standard ERC-20 interface for reading balances and sending transfers", so USDC is listed here. Since the SDK always shows the native balance first, a split on Arc will currently show USDC twice for the same funds, and distributing either row pays out the same balance. Hiding the native row on Arc would fix that; happy to adjust this PR however you prefer.
• Fees: Arc's docs ask for maxFeePerGas of at least 20 gwei; transactions below that may stay pending.
• Indexing: a single ERC-20 USDC transfer emits two Transfer logs, one from the native system emitter and one from the ERC-20 contract. Splits Lite reads balances live and isn't affected; indexers should tell them apart by emitter address (docs).

Related

• Arc support request: splits-contracts-monorepo#77

Checked locally

prettier, bun run lint and bun run build pass. Token name, symbol and decimals were read on-chain on both networks.

[splits-bot-testing]

Status	Commit	Endpoint
Ready	e9f319d	ad88c127.lite.testing.splits.org

[eltontay-circle]

Mainnet transaction hash: https://explorer.arc.io/tx/0x8ef1eee4a8dc0a13687aedb47ea32eccf5478d94ccf10e62be35599191b0a2a4

Testnet transaction hash:
https://explorer.testnet.arc.io/tx/0xe8f45c9daef0b834ada72c0592df09d6b6ce266769731c7ac18ab3d0335d00db