How to Add a Custom Subnet RPC to MetaMask Step by Step

04 October 2026

To add a custom avalanche-chain/avalanche-subnet-consensus-mechanism/">Avalanche subnet RPC to MetaMask, you need the subnet's network details - RPC URL, chain ID, currency symbol, and explorer URL - and then enter them in MetaMask's manual network addition form. This process connects your wallet to a specific subnet so you can interact with its dApps and tokens.

Before You Start

Adding a custom subnet RPC is straightforward, but a few prerequisites prevent common errors. First, ensure MetaMask is installed and unlocked. You should have the subnet's network information ready - typically provided by the subnet's documentation or dApp interface. If you don't have the chain ID or RPC URL, check the subnet's official site or GitHub repository. Also, note that each subnet has its own chain ID; using the wrong one will fail.

MetaMask supports adding networks via two methods: manually entering details or using a one-click "Add to MetaMask" button if the dApp provides one. This guide covers manual entry, which works for any subnet.

Step-by-Step Instructions

Step 1: Open MetaMask and Access Network Settings

Click the MetaMask extension icon in your browser. At the top of the wallet interface, you'll see the current network name (e.g., "Ethereum Mainnet" or "Avalanche C-Chain"). Click that network selector dropdown. A list of previously added networks appears. Scroll to the bottom and click "Add Network". This opens the network addition form.

Step 2: enter subnet network details

The form requires five fields. Fill them in precisely:

• Network Name: Enter a recognizable name for the subnet - e.g., "DFK Subnet" or "DeFi Kingdoms". This is for your reference only.
• New RPC URL: Paste the subnet's RPC endpoint. This is the URL MetaMask uses to communicate with the subnet. It often looks like https://subnet.avax.network/... or a custom domain. Double-check the URL for typos.
• Chain ID: Enter the numeric chain ID for the subnet. This is a required identifier - each subnet has a unique integer (e.g., 53935 for DFK Subnet). Incorrect chain IDs cause connection errors.
• Currency Symbol: Enter the subnet's native gas token symbol. This is not always "AVAX". Many subnets use their own token - e.g., "JEWEL" on DFK Subnet. If unsure, check the subnet's documentation.
• Block Explorer URL (Optional): Add the subnet's block explorer URL if available (e.g., https://subnet-explorer.avax.network/...). This lets you verify transactions and token balances within MetaMask.

Step 3: Save and Switch to the Subnet

After entering all details, click "Save". MetaMask may prompt you to confirm you trust this network. Confirm. The wallet will switch to the new subnet automatically. You should see the network name in the dropdown and the correct chain ID in the wallet interface.

Step 4: Verify the Connection

Send a small test transaction or check your balance to confirm the connection works. If you already hold tokens on this subnet, they should appear in your wallet. If not, you may need to add custom token contracts - use the "Import Tokens" feature with the token's contract address.

Troubleshooting Common Issues

• "Chain ID does not match" error: You entered the wrong chain ID. Double-check the subnet's official documentation. The chain ID is a fixed number - copy it exactly.
• "Could not fetch chain ID" error: The RPC URL is incorrect or the subnet's RPC endpoint is down. Verify the URL with the subnet's team or community. Try a different RPC endpoint if one exists.
• Tokens not showing: You need to add the token contract manually in MetaMask. Go to the "Assets" tab, click "Import Tokens", paste the token contract address, and confirm. The token symbol and decimal places should auto-populate.
• Transactions pending or failing: This indicates a subnet-specific issue - check gas settings or the subnet's status. Subnets have their own gas mechanics; refer to the site's article on native gas tokens for your subnet.

Important Reminders

• Each subnet has its own RPC, chain ID, and gas token. The Avalanche C-Chain uses chain ID 43114 and AVAX as gas. Subnets are separate networks - do not confuse them.
• Adding a custom subnet does not affect your other networks. You can switch between them freely.
• Only use RPC URLs from trusted sources. Malicious RPC endpoints can intercept transactions or display false data. Verify the subnet's official channels.
• If you need to remove a subnet, go to Settings > Networks, find the subnet, and click "Delete".

Adding a custom subnet RPC is a one-time setup per subnet. Once saved, you can switch between the C-Chain and any subnets you've added directly from MetaMask's network dropdown.

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