Connect RPC

Point your wallet at https://rpc.arc-scan.io. One click below, then one thing to check by hand.

Nothing is signed. It only changes a setting inside your own wallet.

The button offers this endpoint to the wallet you pick. It cannot make your wallet select it — that last click is yours:

MetaMaskcheck step 6 — the endpoint is added but not selected.

Rabbycheck steps 3 and 4 — confirm the form Rabby opens.

Chain ID5042USDC · 18 decimals

By hand, in the wallet

Open the network selector

Open the MetaMask extension and click the network chip below the tabs.

Open Manage networks

In the Select network dialog, scroll to the bottom and click Manage networks.

The Select network dialog scrolled to the bottom, with an arrow pointing at the Manage networks button beneath the list of networks.

Edit the Arc network

Find Arc in the list, click the three-dot menu at the right-hand end of its row, then choose Edit.

A single row of the network list: the Arc network, its current endpoint printed underneath the name, and an arrow pointing at the three-dot menu button at the right-hand end of the row.

Add a new RPC URL

On the Edit network screen, open the Default RPC URL dropdown and click + Add RPC URL.

The Edit network screen, with Network name set to Arc. The Default RPC URL dropdown is open, listing the endpoints the wallet already had, and an arrow points at the “+ Add RPC URL” entry at the bottom of that list.

Paste the endpoint

Enter https://rpc.arc-scan.io in the RPC URL field and click Add URL. RPC Name is optional.

The Add RPC URL screen. The RPC URL field contains https://rpc.arc-scan.io, the optional RPC Name field is still empty, and an arrow points at the Add URL button at the bottom.

Select it as the active endpointthe button can’t do this

Adding the URL does not switch to it. Back in the network list, click the small arrow beside the endpoint name under Arc and pick rpc.arc-scan.io.

An endpoint added but not selected changes nothing — the wallet keeps calling whichever one was already active.

The Arc row in the network list, with an arrow pointing at the small chevron beside the endpoint name printed under the word Arc.

Done

Arc now shows rpc.arc-scan.io as its endpoint.

The Arc row in the network list showing rpc.arc-scan.io as the endpoint underneath the network name, with no arrow or annotation on it.

Troubleshooting— MetaMask

“This Chain ID is currently used by the Arc network”

You are on Add network, not Edit. Go back and follow step 3.

Saved, but nothing changed

The endpoint was added and never selected. Repeat step 6.

Requests fail after switching

Reload the site, or close and reopen the extension. If it keeps failing, tell us — that is a bug on our side.

Open settings

Open Rabby and click the gear icon in the top-right corner.

The Rabby extension’s home screen. The gear icon sits in the top-right corner of the blue header, beside the account name, and is marked with an arrow.

Go to Custom Network

Scroll to the bottom of the settings list and click Add Custom Network. Despite the name, every custom network is managed there.

Rabby’s settings panel scrolled to the bottom of the Settings group, with the Add Custom Network row at the end marked with an arrow.

Edit Arc

Find Arc in the list — its row reads Currency: USDC and ID: 5042 — and click the pencil icon on the right of it.

Don’t see Arc? Click Add Custom Network at the bottom instead — same form, values in the table below.

Rabby’s Custom Network screen listing Arc, with its currency and chain id beneath the name, and the pencil icon on the right of the Arc row marked with an arrow.

Paste the endpoint and confirm

Replace the RPC URL with https://rpc.arc-scan.io and click Confirm. Leave the other fields as they are.

Two things look odd and are not: the form is headed Add Custom Network while you edit, and the Chain ID is plain text, not a field.

Rabby’s network form with the chain id 5042 printed above the fields, https://rpc.arc-scan.io filled into the RPC URL field, and the Confirm button at the bottom; both are marked with arrows.

Troubleshooting— Rabby

“Rabby cannot verify the security of custom networks”

A standing notice about custom networks in general, shown for every network on the list.

The Chain ID cannot be edited

Expected. Rabby fixes it once the network exists; only the RPC URL is left to change.

“Chain ID already exists” when adding

Arc is already on your list. Use the pencil icon on the existing entry — step 3.

Requests fail after switching

Reload the dapp, then close and reopen the extension. If it keeps failing, tell us.

Network details— if a wallet asks for all of them

Network name

Arc

RPC URL

https://rpc.arc-scan.io

Chain ID

5042 0x13b2

Currency symbol

USDC

Decimals

Block explorer

https://arc-scan.io

18 decimals is not a typo: Arc’s gas is USDC and the native balance is denominated like any EVM native currency. The ERC-20 USDC contract has 6.