Arc Testnet Guide: Faucet, RPC and First Transactions

The Arc public testnet went live on October 28, 2025 and is genuinely busy — roughly 13.5 million transactions in the week of August 13–19, 2026. With public mainnet still ahead on September 16, 2026, testnet is where every Arc build currently happens.

What are the Arc testnet parameters?

Verified against docs.arc.network in August 2026. These are testnet values only — Circle has not published mainnet chain ID, RPC or explorer, and nothing on this hub invents them.

Step 1: Connect your wallet

Add Arc as a custom EVM network using the values above. In MetaMask that is the network selector, then Add a custom network, then the six fields. Set the currency symbol to USDC — MetaMask may warn about a symbol mismatch, which is expected for a chain that uses a stablecoin as gas.

The full wallet setup walkthrough, including Ledger and other wallets, is here.

Step 2: Claim test USDC from Circle's faucet

Go to faucet.circle.com, select Arc testnet, and paste the address you want funded. The faucet sends test USDC directly; there is nothing to buy and nothing to bridge. Because gas on Arc is USDC, that single drip covers both your balance and your fees — you do not need a second faucet for a native coin, because there isn't one.

If the balance does not appear immediately, check the address on testnet.arcscan.app. The explorer is the source of truth; a wallet showing zero while the explorer shows a balance means the wallet is on a stale RPC connection.

Step 3: Send your first transaction

Send a small amount of test USDC to a second address you control. Watch two things:

• Finality. Arc's Malachite consensus produces deterministic finality in roughly 780 milliseconds. The transaction is settled when consensus commits, not probabilistically final after N confirmations. In practice it feels instant.
• The fee. Testnet transactions have averaged about $0.004. Note that the fee line is denominated in USDC, which is the whole point of the chain. Why that matters.

Then open the transaction hash on testnet.arcscan.app and read it end to end — sender, recipient, value, fee, status. How to read Arcscan properly.

Step 4: Deploy something

Arc is EVM-compatible, so the standard toolchain applies without modification. Point Hardhat or Foundry at https://rpc.testnet.arc.io with chain ID 5042002 and deploy as usual. Solidity contracts that compile for Ethereum compile for Arc.

If you would rather not write or deploy contracts by hand, Team Finance's no-code flow covers token creation, liquidity locks, team locks, vesting, staking pools, airdrops and multisender. Launching a token on Arc without coding walks the whole path.

Moving to mainnet

Arc mainnet opens on 16 September 2026 and every value in this guide changes with it. Nothing you have configured for Circle's Arc testnet carries over untouched, so treat the cutover as a new environment rather than a find-and-replace.

The chain ID changes. Testnet is 5042002; mainnet is 1243 (hex 0x4db) per ChainList. Anywhere that ID is hardcoded — a wallet network config, a deployment script, a front-end network switcher — needs a second branch, not an edited value, because testnet keeps running.

The RPC and explorer URLs do not exist yet. As of 6 September 2026 Circle had not published an official Arc mainnet RPC endpoint or block explorer. Testnet's are https://rpc.testnet.arc.io and testnet.arcscan.app and remain correct for testnet. Copy the mainnet values from docs.arc.io the moment they are published, and from nowhere else. Do not infer them from the testnet pattern, and do not accept one from a post, a Discord message or an ad — a fake "official mainnet RPC" is the most predictable attack of a chain launch week, and it works because everyone is in a hurry on the day.

Contract addresses are reissued, not migrated. Circle's published addresses — USDC, EURC, USYC, the CCTP messenger, the Gateway pair — are testnet-only, with mainnet equivalents marked not yet available. Any address baked into source, a subgraph manifest or an indexer config is a value you will be replacing, not a deployment you will be reusing.

Faucet USDC becomes real USDC. Gas on Arc is paid in USDC, so the mainnet version of "top up from the faucet" is a funded treasury operation: a gas wallet somebody owns, a balance somebody monitors, and gas booked as an operating cost. A hot wallet that runs to zero USDC on Arc does not degrade — it stops.

One useful sanity check before you cut over: not everything you depend on will move on the 16th. Plenty of projects that announced Arc integrations will still be testnet-only weeks later, and several are still on Circle's Arc testnet as of 7 September 2026. If a dependency of yours is on that list, its mainnet date is its own, not Arc's.

What can you not test yet?

Anything mainnet-specific. That includes the mainnet chain ID and RPC, real bridged USDC via CCTP, and any listing or venue integration that depends on mainnet contracts. Public mainnet opens September 16, 2026.

Also worth stating plainly: there is no ARC token to test, farm or claim. The May 2026 whitepaper describes a potential coordination asset in exploratory terms and Circle has made no decision to launch one. Testnet activity is not a confirmed airdrop qualification, and any site telling you it is has invented that. What is actually confirmed about the ARC token.

A short pre-mainnet checklist

• Network added and verified against the explorer.
• Faucet funds received; a first transfer executed and read on Arcscan.
• Contracts deployed and exercised on testnet, not just compiled.
• Launch mechanics rehearsed end to end: mint, lock liquidity, vest, distribute.
• Bookmarks saved for arc.io and docs.arc.network, so mainnet parameters come from Circle rather than from a search result on the day.

Rehearsing the launch sequence is the part most teams skip and most regret. Team Finance has been non-custodial since 2020 and has secured over $2.7 billion across 40,000+ projects on 26 chains — practise the flow now, at $0.004 a transaction, so mainnet day is muscle memory. Start with minting a token.