Mainnet
4663
chain ID
The guide
On the front page I said this was simple. This is me showing my work so you know I didn't make it up.
Fair warning: this bit is written properly, because numbers are the one thing I refuse to be silly about.
This started from zero knowledge — not whether the chain was real, not whether anyone could deploy to it, not what it cost, not whether anything minted on it would ever be seen. What follows is the actual investigation in the order it happened, as seven things we didn't know and the answer each one got.
Every figure below was either measured directly against the chain from our own server or read from Robinhood's official documentation, and each one says which. Nothing is repeated from a thread.
Seven unknowns
Plenty of "chains" are press releases. The fastest way to tell the difference is to stop reading and start knocking: a real chain answers a JSON-RPC call. So the first thing we did was fire eth_chainId at the documented endpoints.
# no keys, no account, no signup curl -X POST https://rpc.mainnet.chain.robinhood.com \ -H 'content-type: application/json' \ -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' {"jsonrpc":"2.0","id":1,"result":"0x1237"} ← 0x1237 = 4663
Both networks responded immediately. Mainnet is chain 4663, live since 1 July 2026. Testnet is chain 46630, live since 10 February 2026. Reachable on the first try with no credentials, which also confirmed the public RPCs are genuinely public.
Robinhood Chain is an Ethereum Layer 2 built on Arbitrum Orbit (the Nitro stack), settling to Ethereum with blob data availability, using ETH as its gas token, with ~100 ms blocks and full EVM compatibility.
We confirmed the Arbitrum lineage rather than taking the docs' word for it, by calling ArbGasInfo — a precompile that only exists at address 0x…6C on Arbitrum Nitro chains. It answered:
perStorageAllocation 863.000000 gwei perArbGasBase 0.020000 gwei perArbGasCongestion 0.023150 gwei perArbGasTotal 0.043150 gwei
A standard ERC-721 works here exactly as it would on Ethereum. Solidity, OpenZeppelin, Foundry, MetaMask and OpenSea all apply unchanged. Anything written for a UTXO chain — Bitcoin, Dogecoin, inscriptions — carries over not at all.
A chain run by a public brokerage could plausibly be permissioned: whitelisted deployers, KYC, an application form. If so, an independent collection would be dead on arrival.
Deployment is open to anyone. No approval, no allowlist, no relationship with Robinhood required. The chain already hosts independent NFT collections and community tokens alongside Robinhood's own Stock Tokens.
This is the question that kills most Ethereum NFT projects — an L1 launch can cost thousands in gas. We measured it, pulling the live base fee off the chain and multiplying by realistic gas figures.
Base fee measured at 0.04315 gwei. Priority fee is zero. At ETH $1,890 a complete collection launch costs well under a dollar. Full table below.
A collection on a chain with no marketplace support is invisible, and building your own gallery is the expensive part of any NFT project.
OpenSea supports Robinhood Chain natively, web and mobile. A standard ERC-721 on 4663 is indexed, displayed, listed and traded with no work from you. There is also HOODIES, a chain-native NFT marketplace with self-serve listing, free for the first 100 collections. The chain has already seen tens of thousands of mints and secondary sales.
ETH on Ethereum, Base or anywhere else cannot pay Robinhood Chain gas. It has to physically be on chain 4663, so before a line of Solidity matters you need a funded address there.
The trustless route is the canonical Arbitrum bridge (Ethereum → Robinhood Chain, ~10 minutes, you pay Ethereum L1 gas). Faster third-party routes exist — Relay and Across settle in seconds, plus Stargate, Chainlink CCIP and LI.FI/Jumper. Going back is slower: withdrawals carry Arbitrum's 7-day challenge period. Still open: whether the Robinhood app itself can withdraw ETH straight onto the chain, which would skip L1 gas entirely. The docs don't say.
Foundry (forge, cast, anvil) plus OpenZeppelin's audited ERC-721 is the whole build environment. Foundry ships as standalone binaries with no Node dependency, which makes it the lighter choice over a Hardhat/npm setup.
Base fee 0.04315 gwei measured live · priority fee 0 · ETH at $1,890
| Operation | Gas (est.) | ETH | USD |
|---|---|---|---|
| Deploy full ERC-721 (OpenZeppelin, enumerable) | 2,800,000 | 0.00012082 | $0.23 |
| Deploy lean ERC-721A (batch-optimised) | 1,800,000 | 0.00007767 | $0.15 |
| One mint | 150,000 | 0.00000647 | $0.012 |
| One transfer / sale | 60,000 | 0.00000259 | $0.005 |
| Deploy + mint an entire 250-piece collection | ~40,300,000 | 0.00173 | $3.29 |
Cost is not the constraint on this chain. Minting 250 pieces outright is about three dollars of gas. The same collection on Ethereum L1 would be four figures. Funding a deployer with 0.01 ETH (~$19) leaves headroom for a launch plus years of operations.
Honest caveat: the gas figures for contract operations are standard-contract estimates, not measurements of a specific contract. The base fee, the priority fee and the ETH price are measured. Before anyone spends real money off these numbers, they get replaced with forge's exact output and re-checked on testnet.
Distribution is already solved
Robinhood Chain is a supported network on OpenSea web and mobile. A standard ERC-721 is indexed automatically — no submission, no integration.
Collection page, traits, rarity, offers and royalties all come free.
The first NFT marketplace built specifically on Robinhood Chain. Self-serve ERC-721 listing, hand-reviewed, free for the first 100 collections.
Worth listing on both — it costs a form.
Real ETH, on chain 4663, before anything ships
| Route | Speed | Cost | Notes |
|---|---|---|---|
| Canonical Arbitrum bridge | ~10 min | Ethereum L1 gas | Trustless, security inherited from Ethereum. The default. |
| Relay | seconds | route fee | Bridge-and-execute in one transaction |
| Across | seconds | route fee | Intents-based, capital efficient |
| Stargate / LayerZero | minutes | route fee | OFT transfers |
| Chainlink CCIP | minutes | route fee | Messaging plus token transfer |
| LI.FI / Jumper | seconds–min | route fee | Aggregates the above |
Withdrawing is the slow direction. Exiting to Ethereum is three steps: initiate on L2, wait the 7-day challenge period Arbitrum's fraud-proof system requires, then claim on L1 and pay L1 gas. Money that goes in should be money you intend to leave in.
If a deposit's L2 leg fails — usually for insufficient gas — the funds are not lost and can be manually redeemed from the bridge interface within 7 days.
The order that avoids expensive mistakes
forge, cast, anvil plus OpenZeppelin contracts. Standalone binaries, no npm.forge test against a local anvil before it touches a network.| Mainnet | Testnet | |
|---|---|---|
| Chain ID | 4663 | 46630 |
| RPC | rpc.mainnet.chain.robinhood.com | rpc.testnet.chain.robinhood.com |
| WebSocket | wss://feed.mainnet.chain.robinhood.com | wss://feed.testnet.chain.robinhood.com |
| Sequencer | sequencer.mainnet.chain.robinhood.com | sequencer.testnet.chain.robinhood.com |
| Explorer | robinhoodchain.blockscout.com | explorer.testnet.chain.robinhood.com |
| Gas token | ETH | ETH |
| Live since | 1 July 2026 | 10 February 2026 |
Stack: Arbitrum Orbit / Nitro · settles to Ethereum · blob data availability · ~100 ms blocks · fully EVM-compatible · permissionless deployment. Public RPCs are rate-limited and explicitly not for production; Alchemy is the recommended production provider. Official docs: docs.robinhood.com/chain.