If you hold Bitcoin but have always watched Ethereum-style apps from the sidelines, Merlin Chain is one of the networks trying to change that. It is a Bitcoin Layer 2 that runs the Ethereum Virtual Machine, which means you can use familiar wallets like MetaMask to interact with Bitcoin-native assets, Ordinals, and BRC-20 tokens without learning a whole new wallet stack. The catch? MetaMask does not list Merlin Chain by default, so you have to add it yourself before you can use it.
In this guide you will learn what Merlin Chain is and how it works, why it belongs in your MetaMask, and how to add it step by step — both the one-click method and the manual RPC method. You will also learn how to verify the network was added correctly, the mistakes that trip up most beginners (including the unusual fact that this network uses BTC for gas), and how to spot phishing scams that target people adding new networks.
id=”what-is-merlin-chain”>What Merlin Chain Is
Merlin Chain describes itself as a “native Bitcoin Layer 2.” In plain terms, it is a separate blockchain that settles back to Bitcoin while offering the kind of smart-contract functionality Bitcoin’s base layer does not have. It is EVM-compatible, meaning it runs the same virtual machine as Ethereum, so any wallet that speaks Ethereum — MetaMask included — can connect to it with a simple network configuration.
Under the hood, Merlin Chain uses zero-knowledge rollup technology. Transactions are executed on the Merlin network, bundled together, and then submitted to the Bitcoin network for final validation. The design goal is to offer fast, low-cost transactions while inheriting a level of security anchored to Bitcoin itself. This is the same general architecture used by many Ethereum Layer 2s, except the settlement layer is Bitcoin rather than Ethereum.
What makes Merlin Chain different from most EVM networks is its focus on Bitcoin-native assets. The network supports major Bitcoin L1 protocols and standards, including BRC-20 tokens, Ordinals inscriptions, Bitmap, BRC-420, Atomicals, and others. Inscriptions created on Bitcoin L1 are whitelisted on Merlin Chain, so users can trade them cheaply on the Layer 2 instead of paying Bitcoin mainnet fees for every action. The network’s governance token is MERL, which was launched as a BRC-20 token on Bitcoin — a deliberate choice to keep the project “Bitcoin native” rather than issuing a standard Ethereum token.
One detail that matters enormously for this guide: Merlin Chain uses BTC as its gas currency. When you pay transaction fees on Merlin Chain, you pay in BTC, not ETH. This is unusual among EVM networks and is the single biggest source of confusion for new users, so we will come back to it several times.
Why Add Merlin Chain to MetaMask
You might wonder why you should bother adding another network when MetaMask already works fine for Ethereum. The honest answer depends on what you want to do. If you have no interest in Bitcoin Layer 2 activity, Ordinals, or BRC-20 tokens, you can safely skip this guide. But if any of the following apply, adding Merlin Chain makes sense:
You hold BTC and want to use it in DeFi-style apps. Bitcoin’s base layer is deliberately simple — it does not run lending protocols, decentralized exchanges, or NFT marketplaces the way Ethereum does. Merlin Chain brings that functionality to Bitcoin-adjacent assets, and MetaMask is the bridge that lets you access it with a wallet you already know.
You trade Ordinals or BRC-20 tokens. Moving inscriptions and BRC-20 tokens on Bitcoin mainnet can be slow and expensive. Merlin Chain lets you trade these assets with much lower fees. Since your MetaMask address on Merlin Chain is the same address you use on Ethereum (EVM addresses are identical across networks), you do not need to manage a second set of keys.
You want one wallet for everything. Adding Merlin Chain means your existing MetaMask seed phrase, hardware wallet connection, and address book all carry over. You get a new network tab in the same interface instead of installing and securing a separate Bitcoin L2 wallet.
That said, keep expectations grounded. Merlin Chain is a relatively young network in a fast-moving and experimental corner of crypto. Bridges, new Layer 2s, and Bitcoin-adjacent protocols carry real technical risk — bugs, bridge failures, and liquidity crunches have all happened in this space. Adding the network to MetaMask is safe and reversible; putting significant money on it is a separate decision you should make carefully. If you are new to switching networks safely, our walkthrough on how to switch networks in MetaMask safely covers the habits that keep you out of trouble.
The One-Click Method (Chainlist)
The fastest way to add Merlin Chain is through a chain directory — a website that lists verified EVM network configurations and lets you add them to MetaMask with a couple of clicks. The best-known directory is Chainlist (chainlist.org). Here is how it works:
Step 1 — Open Chainlist. Type the address into your browser yourself rather than clicking a link from a search result, email, or social media post. Fake copies of chain directories are a known phishing vector, and the real site is easy to imitate.
Step 2 — Connect your wallet. Click the “Connect Wallet” button, usually in the top-right corner, and approve the connection in MetaMask. Connecting to Chainlist only lets the site suggest networks; it does not give the site permission to move your funds. Still, as a habit, disconnect from sites you are not actively using.
Step 3 — Search for Merlin. Use the search bar and type “Merlin”. You should see an entry for the Merlin mainnet. Check that the chain ID shown is 4200 — that number is the network’s unique fingerprint, and it is the fastest way to confirm you are looking at the right entry and not an imposter.
Step 4 — Add to MetaMask. Click the “Add to MetaMask” button on the Merlin entry. MetaMask will pop up a confirmation showing the network details it is about to add. Review them — network name, RPC URL, chain ID 4200, currency symbol BTC, block explorer — then click Approve. If the popup suggests switching to Merlin Chain, you can accept or stay where you are.
The one-click method is convenient because it eliminates typos, which are the most common cause of broken manual setups. Its weakness is trust: you are relying on the directory’s listing being correct and on being on the genuine site. That is why the manual method below is worth knowing even if you use Chainlist — it teaches you what “correct” looks like, so you can spot when something is off.
| Method | Speed | Typo risk | Trust required | Best for |
|---|---|---|---|---|
| Chainlist one-click | Under a minute | None | The directory site is genuine | Beginners who want speed |
| Manual RPC entry | A few minutes | Moderate — double-check each field | Only yourself and the values you type | Anyone who wants full control |
| From a dapp prompt | Seconds | None | The dapp suggesting the network | Users already on a Merlin app |
The Manual RPC Method, Step by Step
Adding Merlin Chain manually takes a few minutes and gives you complete control over what gets saved in your wallet. Below are the network parameters, grounded from multiple public sources and presented as of this guide’s writing. Networks occasionally update their infrastructure, so if MetaMask rejects a value or something looks different, pause and cross-check against Merlin Chain’s official documentation before proceeding.
| Field | Value to enter | What it means |
|---|---|---|
| Network name | Merlin Mainnet | The label shown in your network dropdown |
| RPC URL | https://rpc.merlinchain.io | The server MetaMask talks to for Merlin Chain data |
| Chain ID | 4200 | The network’s unique identifier — must match exactly |
| Currency symbol | BTC | Gas fees on Merlin Chain are paid in BTC |
| Block explorer URL | https://scan.merlinchain.io | Where you can look up transactions (optional but useful) |
Step 1 — Open MetaMask and find the network menu. Click the network dropdown at the top of the MetaMask window. It probably says “Ethereum Mainnet” or whichever network you last used.
Step 2 — Start adding a network. Click “Add network” at the bottom of the dropdown. MetaMask will open a network browser page showing popular networks. Merlin Chain may or may not appear there — either way, scroll down and click “Add a network manually.”
Step 3 — Fill in the form. Enter the five values from the table above, exactly as shown. The two fields where mistakes matter most are the RPC URL and the Chain ID. A wrong RPC URL means MetaMask talks to the wrong server (or nowhere); a wrong chain ID means you could be tricked into signing transactions for a different network. Type them carefully, then read them back before saving.
Step 4 — Save. Click “Save.” MetaMask will add Merlin Mainnet to your network list. You will usually be asked whether you want to switch to it immediately — say yes if you want to start using it, or stay on your current network and switch later from the dropdown.
A note on the RPC URL. The address above is the widely documented public endpoint for Merlin Chain, but public RPCs can change, rate-limit, or go down. If MetaMask ever shows Merlin Chain as unreachable while your internet is fine, the RPC endpoint is the first thing to suspect — check Merlin Chain’s official docs for the current recommended endpoint rather than grabbing one from a random forum post.
How to Verify You Did It Right
Adding the network takes a minute; confirming it works correctly takes two more and saves you from nasty surprises later. Run through these checks:
1. Confirm the chain ID. Switch to Merlin Mainnet in the network dropdown, then check that MetaMask shows the network as connected. The surest verification is the chain ID: a quick way to confirm is to compare against a known-good source. If anything was mistyped, delete the network (Settings → Networks → select it → Delete) and re-add it.
2. Check the currency symbol. With Merlin Mainnet selected, your balance should display in BTC, not ETH. If it shows ETH, the currency symbol was entered incorrectly — edit the network and fix it. This matters because a wrong symbol can confuse you about what you are actually paying for gas.
3. Look up the explorer. Open the block explorer address in your browser by typing it yourself, then search for your wallet address. Seeing your address resolve on the Merlin Chain explorer confirms you are pointed at the real network.
4. Send a tiny test transaction first. Before moving any meaningful amount of BTC to Merlin Chain, send the smallest amount you can and confirm it arrives. Only then move larger sums. This is the single cheapest insurance in crypto, and it applies to every new network you ever add — see our Polygon setup guide for the same habit applied elsewhere.
5. Understand how BTC gets there. Your existing BTC on the Bitcoin mainnet does not automatically appear on Merlin Chain. You need to bridge it — locking BTC on Bitcoin L1 and receiving a representation of it on Merlin. Bridging is a separate process with its own fees, waiting times, and risks, and it is where most users lose money to phishing sites. Only use bridges you have independently verified, and be deeply suspicious of any bridge link sent to you by a stranger.
Common Mistakes to Avoid
Mistake 1 — Expecting ETH for gas. Almost every EVM network tutorial you have ever read says “you need ETH for gas.” Merlin Chain breaks that rule: gas is paid in BTC. New users often bridge tokens over, try to transact, and get a confusing “insufficient funds” error because their wallet holds no BTC on Merlin Chain. Always keep a small amount of BTC on the network for fees.
Mistake 2 — Sending BTC to your MetaMask address on the wrong network. Your MetaMask address is identical across all EVM networks, which is convenient — and dangerous. Sending BTC from an exchange to your address while MetaMask is set to Ethereum mainnet does not put BTC on Merlin Chain; depending on what the exchange actually sent, those funds may be difficult or impossible to recover. Always confirm which network you are operating on before every deposit or withdrawal.
Mistake 3 — Using a fake RPC URL. RPC phishing is subtle: everything looks normal, but your wallet is talking to an attacker’s server. Symptoms include balances that do not match the explorer, transactions that never confirm, or prompts to “reconnect” repeatedly. If anything feels off, compare what MetaMask shows against the official block explorer and consider re-adding the network with a freshly verified RPC URL.
Mistake 4 — Confusing Merlin Chain with similarly named projects. Crypto is full of similar names. “Merlin” appears in several unrelated projects, and a search for setup instructions can surface guides for the wrong one. The chain ID check — 4200 — is your anchor. If a guide’s numbers do not match, you are reading about a different network.
Mistake 5 — Skipping the test transaction. It is tempting to move everything at once to save on fees. Do not. Bridge and network issues are most painful at scale; a tiny test costs almost nothing and catches configuration errors, wrong addresses, and bridge problems before they become expensive. For a broader safety refresher, our Soneium setup guide walks through the same verification mindset on another network.
FAQs
The Bottom Line
Adding Merlin Chain to MetaMask takes a few minutes: either approve it through a chain directory after verifying chain ID 4200, or enter the network details manually and double-check the RPC URL. The two things that make this setup different from most networks are the BTC-denominated gas and the bridging step required to get funds onto the Layer 2 — get those right, start with a test transaction, and the rest works like any EVM network you already know.
Merlin Chain is an interesting experiment in bringing Ethereum-style apps to Bitcoin, but it is still young infrastructure in a risky corner of crypto. Add the network freely, explore cautiously, and keep position sizes small until the ecosystem matures.
This guide is for education only — not financial advice.
