Live working document

Launching an NFT collection on Robinhood Chain

This page starts from zero knowledge. The brief was four words — "use Robinhood Chain" — and nothing else was known: not whether it was real, not whether we could deploy to it, not what it cost, not whether anyone would ever see the result.

What follows is the actual investigation, in the order it happened. Every number below was either measured directly against the chain from our server or read from the official docs, and each one says which.

Mainnet

…

chain ID

Block height

…

live from RPC

Gas price

…

gwei · base fee

Deploy cost

…

ERC-721, at current gas

Testnet

…

chain ID

Queried live in your browser, straight from rpc.mainnet.chain.robinhood.com — no server of ours in the middle. If those read "…" the public RPC is rate-limiting; the numbers in the tables below are from our own measurements and stand on their own.

The journey, in order

Seven things we didn't know, and how each got answered.

Unknown 01

Is Robinhood Chain a real, running blockchain — or an announcement?

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 very first thing we did was fire eth_chainId at the documented endpoints from the server.

# from the VPS, 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

Answered — it's real and it's up

Both networks responded immediately. Mainnet is chain 4663, live since 1 July 2026. Testnet is chain 46630, live since 10 February 2026. Both were reachable from our box on the first try with no credentials — which also told us the public RPCs are genuinely public.

Unknown 02

What kind of chain is it? Do our existing crypto tools work here?

This mattered more than anything else, because everything we've built in crypto so far is Dogecoin — a UTXO chain, with a signing core, a UTXO classifier and an inscription engine written specifically for it. If Robinhood Chain were its own exotic thing, we'd be starting from nothing.

It isn't. 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 block times and full EVM compatibility.

We confirmed the Arbitrum lineage ourselves rather than taking the docs' word for it — by calling the ArbGasInfo precompile, a contract that only exists at address 0x…6C on Arbitrum Nitro chains. It answered:

# ArbGasInfo.getPricesInWei() — an Arbitrum-only precompile
perStorageAllocation  863.000000 gwei
perArbGasBase           0.020000 gwei
perArbGasCongestion     0.023150 gwei
perArbGasTotal          0.043150 gwei

Answered — it's plain EVM, and none of our Doge code carries over

A standard ERC-721 works here exactly as it would on Ethereum. That's the good news and the bad news: the entire Dogecoin toolchain (dogewallet-core.js, the UTXO rules, doginals) is irrelevant to this project, and this becomes the first EVM project on the platform. Everything transferable comes from the Ethereum world instead — Solidity, OpenZeppelin, Foundry, MetaMask, OpenSea.

Unknown 03

Can we even deploy to it — or does Robinhood have to let us in?

A chain run by a public brokerage could plausibly be permissioned: whitelisted deployers, KYC, an application form. If so, an independent art collection would be dead on arrival.

Answered — permissionless

Contract deployment on Robinhood Chain is open to anyone. No approval, no allowlist, no relationship with Robinhood required. The chain already hosts a growing set of independent NFT collections and community tokens alongside Robinhood's own Stock Tokens. We can ship without asking anybody.

Unknown 04

What does it actually cost to deploy and to mint?

This is the question that kills most Ethereum NFT projects — an L1 collection launch can cost thousands of dollars in gas. We measured it rather than guessing, pulling the live base fee off the chain and multiplying by realistic gas figures.

Answered — it is effectively free

Base fee measured at 0.04315 gwei. Priority fee is zero. At an ETH price of $1,890, a complete collection launch costs well under a dollar. See the full table below.

Unknown 05

If we mint it, will anyone ever see it?

The hardest problem with our Dogecoin collections has always been distribution — Doginals live in a small ecosystem with thin marketplace support, so we had to build our own galleries and mint pages for every single collection. If Robinhood Chain NFTs were invisible to the major marketplaces, we'd be doing that all over again.

Answered — and this is the single best finding of the day

OpenSea supports Robinhood Chain natively, on both web and mobile. A standard ERC-721 deployed to chain 4663 gets indexed, displayed, listed and traded there without us building any of it. There is also HOODIES, a Robinhood-Chain-native NFT marketplace with self-serve listing. The chain has already seen tens of thousands of mints and secondary sales.

Unknown 06

How does real ETH get onto the chain to pay for it?

ETH on Ethereum, Base, or anywhere else cannot pay Robinhood Chain gas. The ETH has to physically be on chain 4663. So before a single line of Solidity matters, we need a funded address there.

Answered, with one open item

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 the other way is slower: withdrawals carry Arbitrum's standard 7-day challenge period. The open item is whether the Robinhood app itself can withdraw ETH straight onto Robinhood Chain, which would skip L1 gas entirely — see open questions.

Unknown 07

Can this box actually build an EVM contract today?

The platform has never done EVM work. We audited what's installed before assuming anything.

node        v20.19.2   present
npm         missing
forge/cast  missing    (Foundry)
solc        missing    (Solidity compiler)
python web3 missing
disk free   143 GB    plenty

Answered — nothing installed, but nothing hard either

The box has no EVM toolchain at all. The fix is one install: Foundry ships forge, cast and anvil as standalone binaries with no Node dependency, which suits this box far better than a Hardhat/npm setup. That plus OpenZeppelin's audited ERC-721 is the whole build environment.

What it costs

Base fee 0.04315 gwei measured live off chain 4663 · priority fee 0 · ETH at $1,890.

Operation	Gas (est.)	Cost in ETH	Cost in 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

The cost is not the constraint here. Minting a 250-piece collection outright costs about three dollars in gas. For comparison, the equivalent Dogecoin collection work has run to tens of DOGE in inscription fees, and the same collection on Ethereum L1 would be four figures. Fund the deployer with 0.01 ETH (~$19) and there is more than enough headroom for the launch plus years of operations.

Gas figures are standard-contract estimates, not measurements of our contract — we don't have one yet. They'll be replaced with forge's exact numbers, and re-checked on testnet, before anything is deployed to mainnet with real money. The base fee, priority fee and ETH price are measured.

Getting seen

Distribution is solved for us, which changes what we have to build.

OpenSea native support

Robinhood Chain is a supported network on OpenSea web and mobile
A standard ERC-721 is indexed automatically — no submission, no integration work
Collection page, traits, rarity, offers and royalties all come free
Secondary trading works out of the box

HOODIES chain-native

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 — costs nothing but a form

This is the sharpest break from how we've done crypto so far. Every Doginal collection needed its own gallery, its own mint page and its own explainer, because nothing else would show them. Here, the marketplace layer already exists — so our own site becomes the story and the mint front door, not the infrastructure of last resort.

Funding the deployer

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. Getting value back to Ethereum is a three-step exit: initiate on L2, wait the 7-day challenge period that Arbitrum's fraud-proof system requires, then claim on L1 and pay L1 gas. Money that goes in should be money we intend to leave in. Funding 0.01 ETH keeps the amount at stake trivial regardless.

Safety note: if a deposit's L2 leg fails — typically for insufficient gas — the funds are not lost and can be manually redeemed from the bridge interface within 7 days.

The plan

What has to happen, in order, to get a collection live.

Install the toolchainFoundry (forge, cast, anvil) plus OpenZeppelin contracts. Standalone binaries, no npm needed. One-time setup on the box.
Decide the collectionThe one genuinely open creative question: what the art is, how many pieces, and the mint model. This is the only step blocked on a decision rather than on work — see below.
Write and test the ERC-721Contract with the metadata URI scheme, supply cap, mint rules and royalty settings. Full test suite under forge test, run against a local anvil fork before it goes anywhere near a network.
Generate the art and metadataImages plus per-token JSON. Hosting is already solved: Caddy serves it from this box, exactly as it does for every other site here. IPFS optional if we want the metadata to outlive the server.
Full dress rehearsal on testnetDeploy the real contract to chain 46630, mint, transfer, and confirm the metadata renders. Free, and it catches everything a mainnet mistake would cost us.
Fund the mainnet deployerGenerate the key in the age vault, bridge 0.01 ETH in, verify the balance on chain 4663.
Deploy to mainnet and verifyShip to chain 4663, then verify the source on the Blockscout explorer so the contract is publicly readable — an unverified contract reads as a scam.
List and launchConfirm the OpenSea collection page renders, submit to HOODIES, and turn this page into the public mint front door with the story behind the collection.

Step 2 is the only real blocker. Everything else is mechanical work we can now cost, schedule and execute with confidence. What the collection actually is — the art, the size, the idea — is yours to call.

Open questions

Honest list of what we still don't know.

open Direct funding from the Robinhood app

Can ETH be withdrawn from the Robinhood app straight onto Robinhood Chain, skipping Ethereum L1 gas entirely? The chain docs don't address it. Given the account already exists, this is worth ten minutes of checking before we pay to bridge.

open Exact deploy gas

The cost table uses standard-contract estimates. Real numbers come from forge once the contract exists — though at $0.23 the estimate would have to be wrong by 100× to matter.

open Royalty enforcement

ERC-2981 sets a royalty on-chain, but whether it's honoured depends on the marketplace. Needs confirming for OpenSea on this chain specifically.

open Metadata permanence

Serving metadata from this box is free and instant, but ties the collection's images to our uptime. IPFS or Arweave is the alternative. A judgement call tied to how permanent the collection is meant to be.

Reference card

	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. Docs: docs.robinhood.com/chain.