How to add Arc to MetaMask (RPC, chain ID, and the safe way to do it)

Arc isn't in MetaMask's default network list, so you add it as a custom network by hand. The testnet settings below are confirmed and safe to copy today; the mainnet ones are only partly published, and the single most dangerous thing you can do is paste an RPC URL a stranger sent you. Here's how to do it right.

The short answer: to add Arc you open your wallet's "Add a custom network" screen and enter five fields — network name, RPC URL, chain ID, currency symbol, and block explorer. For Arc testnet those values are confirmed. For mainnet (live 16 September 2026), the chain ID is known but the official RPC and explorer weren't published as of 1 Sep 2026, so you must copy them from docs.arc.io when the network goes live. Never take them from anywhere else.

First, the safety rule that matters more than any setting

An RPC URL is the address your wallet talks to for every balance check and every transaction. A malicious RPC can lie to you — show fake balances, misreport what a transaction will do, and route you into signing something you'd never approve. Feeding people a fake "official" RPC is a well-worn wallet-drainer vector, and it spikes around any high-profile mainnet launch. Arc's is exactly the kind of launch that attracts it.

So, one rule before anything else: only ever get Arc's network values from the official source, https://docs.arc.io. Not from a Discord DM, not from a reply under a launch tweet, not from a "helpful" support account, not from this article's numbers if they conflict with what docs.arc.io shows on the day. If someone sends you an RPC URL and tells you to add it to transact with them, treat that as an attempted theft. There is no legitimate reason a stranger needs you to add their custom RPC. (More patterns like this in our guide to Arc memecoin scams and how to stay safe.)

The Arc testnet settings (confirmed as of 1 Sep 2026)

These are live and correct today. Use them if you're testing before mainnet.

• Network name: Arc Testnet
• RPC URL: https://rpc.testnet.arc.io
• WebSocket (optional): wss://rpc.testnet.arc.io
• Chain ID: 5042002
• Currency symbol: USDC
• Currency decimals: 18
• Block explorer: https://testnet.arcscan.app
• Test USDC faucet: https://faucet.circle.com

Gas on Arc is paid in USDC, so the currency symbol is USDC, not ETH — with 18 decimals. You'll need test USDC from the Circle faucet above before you can send anything (see the gas note below). Reviewed as of 1 Sep 2026.

The Arc mainnet settings (partly published — read this carefully)

Arc mainnet is scheduled for 16 September 2026. As of 1 Sep 2026, only one value is public:

• Chain ID: 1243 (hex 0x4db), per ChainList's Arc entry.
• RPC URL: not yet published. Copy it from https://docs.arc.io at mainnet.
• Block explorer: not yet published. Same — from docs.arc.io.
• Currency symbol: USDC, 18 decimals (same model as testnet).

Don't fill in a mainnet RPC from memory, a cached page, or a third party. The chain ID being public doesn't help an attacker; a fake RPC does. When mainnet is live, the correct move is: open docs.arc.io yourself, copy the RPC and explorer it lists, and enter those. If ChainList and docs.arc.io ever disagree, docs.arc.io wins — it's the issuer's own documentation.

Adding a custom network, step by step

This works the same in MetaMask and, with minor wording changes, in most EVM wallets (the field names are near-identical across Rabby, Coinbase Wallet, OKX Wallet, and others).

1. Open your wallet and click the network selector — the dropdown at the top showing your current network (e.g. "Ethereum Mainnet").
2. Choose Add network, then Add a network manually (in MetaMask) or Custom network / Add custom network (other wallets).
3. Fill the five fields from the correct block above: Network name, RPC URL, Chain ID, Currency symbol, and Block explorer URL.
4. If the wallet warns that the chain ID doesn't match a known network, that's expected for a new chain — but it's also your cue to double-check the RPC came from docs.arc.io.
5. Save, then switch to Arc from the same network dropdown.

If your wallet refuses the network, the usual cause is a chain ID that doesn't match what the RPC reports, or an RPC that's unreachable. Re-check the chain ID against the official source rather than trying a different RPC someone offered you.

Why you need USDC in the wallet before you can do anything

On most chains you hold the native gas token (ETH, BNB) to pay fees. Arc is different: gas is paid in USDC. That's deliberate — Arc is Circle's stablecoin-native Layer-1, so fees are dollar-denominated and predictable. But it has a practical consequence: an Arc wallet with zero USDC can't transact at all. There's no separate gas token to top up; if you can't cover the USDC fee, the transaction won't send.

On testnet, get test USDC from https://faucet.circle.com. On mainnet, you'll need real USDC on Arc, which means bridging it in — Circle's own CCTP moves USDC across chains by burn-and-mint, and there are non-custodial routes for it. Our walkthrough on bridging to Arc covers the options and the order of operations (fund first, then transact). Not financial advice.

One display note: because the gas token is USDC, wallets built to show custom gas tokens render Arc fees most cleanly. Standard EVM wallets still transact fine — the fee just shows in USDC terms. If you want a wallet chosen for how well it handles this, see which wallets work best with Arc.

Hardware wallet users (Ledger and similar)

A hardware wallet doesn't change any of the above. You add the Arc network in the software wallet you pair with the device (MetaMask, for instance), using the exact same settings, and the Ledger signs Arc transactions as it would on any EVM chain. The safety rule is identical — and arguably matters more, since the whole point of a hardware wallet is that you verify what you sign. A malicious RPC undercuts that by misrepresenting the transaction on screen, so the "only from docs.arc.io" rule is not optional just because your keys live on a device.

Where this fits

Adding the network is step one; what you do next — bridging USDC, then looking at what's launching — is where the real risk lives. Meme Central indexes Arc launches with automatic impersonation and ticker-collision flags, and never picks coins for you. If you're evaluating where tokens are being created on Arc, our roundup of the launchpads operating on Arc lays out the landscape neutrally. You can also start from the TrustSwap Arc hub. Meme Central is part of the TrustSwap ecosystem.

Not financial advice. Memecoins are extremely high risk.

Frequently asked questions

What is the Arc chain ID?

Testnet is 5042002 (confirmed). Mainnet is 1243, hex 0x4db, per ChainList. Always confirm the current value against https://docs.arc.io, especially at and after the 16 September 2026 mainnet launch.

What is the official Arc RPC URL?

Testnet's confirmed RPC is https://rpc.testnet.arc.io. The official mainnet RPC was not yet published as of 1 Sep 2026 — copy it from https://docs.arc.io when mainnet is live, and never from a URL someone sends you.

Why does MetaMask show USDC instead of ETH for gas on Arc?

Because Arc pays gas in USDC (18 decimals) by design — it's Circle's stablecoin-native chain, so fees are dollar-denominated. That's expected, not a misconfiguration.

Can I use a Ledger or other hardware wallet with Arc?

Yes. Add the Arc network in the software wallet paired with your device and use the same settings; the hardware wallet signs Arc transactions like any EVM chain.

I have USDC bridged but transactions still fail — why?

Most often the wallet is pointed at an unreachable or wrong RPC, or the chain ID doesn't match. Re-verify both against docs.arc.io. Also confirm the USDC is actually on Arc, not on the chain you bridged from.

Is it safe to add an RPC someone sent me so we can trade?

No. A custom RPC controls what your wallet sees and signs, and fake "official" RPCs are a known wallet-drainer tactic. There's no legitimate reason a stranger needs you to add theirs. Only use values from https://docs.arc.io.