NFT Drop Launch (OpenSea programmatic)

When to Use

• User wants to CREATE their own NFT collection/drop on OpenSea (not mint someone else's).
• Deploying a SeaDrop ERC721/ERC1155 contract on any OpenSea-supported chain.
• Configuring allowlist/GTD + public sale stages for a drop.
• Chain of interest includes Robinhood Chain (chainId 4663) — verified live 2026-08-24.

The key endpoint: POST /api/v2/drops/deploy

OpenSea API v2 builds the ready-to-sign deployment transaction for you. No Solidity, no forge needed:

POST https://api.opensea.io/api/v2/drops/deploy
x-api-key: <key from developer-approved account>
{
  "chain": "robinhood",
  "contract_name": "...",
  "contract_symbol": "...",
  "drop_type": "seadrop_v1_erc721",
  "sender": "<deployer address>",
  "token_type": "erc721_standard"
}

Response 200: {chain, data (creation bytecode), to ("0x000…0" = contract creation), value}. Sign data with the sender wallet and broadcast to chain.

• Valid token_type: erc721_standard | erc721_clone | erc721_upgradeable | erc1155_standard | erc1155_clone | erc1155_upgradeable. Bare "erc721" is rejected with the full list (useful discovery trick when docs are thin).
• Requires an API key from a developer-approved account (isDeveloperAccountApproved true — checkable via SIWE flow, see opensea-nft-operations).
• After broadcasting, configure stages and verify with GET /api/v2/drops/{slug} (stages, price, max_per_wallet, times). Existing RH drops use stage types signed_presale (GTD) and public_sale.

Auth quirks that waste hours if unknown

1. SIWE nonce/verify endpoints return JSON only with accept: application/json. Reusing a page-fetch header builder with accept: text/html makes them return the Next.js HTML shell → JSON.parse crash. Keep a JSON-only header set for auth calls.
2. Save the cookie jar immediately after verify — access_token/refresh_token land in the verify response's Set-Cookie headers.
3. Cookies do NOT carry into headless-browser sessions of opensea.io. The studio web app reads auth from the Privy SDK's localStorage/IndexedDB state; cookie injection alone still shows "Connect Wallet". Don't burn time on it.
4. gql.opensea.io uses Apollo persisted queries — introspection returns empty (mutationType.fields: []). Studio mutations are only reachable via sha256Hash registry entries baked into their app bundles. The REST /drops/deploy route above is the supported programmatic path; use it instead of reverse-engineering GraphQL.
5. Studio UI route: https://opensea.io/studio/create/collection (requires the full browser Privy session). Manual fallback if API path breaks.

Robinhood Chain facts

• chainId 0x1237 = 4663. Alchemy: https://robinhood-mainnet.g.alchemy.com/v2/<key>.
• Public RPC: https://rpc.mainnet.chain.robinhood.com.
• OpenSea chain slug: robinhood; studio registry says contractDeploymentEnabled: true.
• Deploy gas observed: ~4.5M units, base fee ~20 gwei → ~0.0002 ETH. Keep ≥0.002 ETH in the deployer wallet for deploy + stage config.
• Existing drops pattern: seadrop_v1_erc721 with GTD presale then public sale, price in native ETH (price_currency_address = zero address).

Launch sequence

1. Verify chain slug via GET /api/v2/chains.
2. Confirm deployer wallet funded (gas estimate × buffer).
3. eth_estimateGas the returned deploy payload before signing.
4. Sign + broadcast; persist TxHash; get contract address from receipt.
5. Configure drop stages (allowlist proofs/vouchers + public params).
6. Verify via GET /api/v2/drops/{slug}; only then wire up mint testing.