Frequently Asked Questions
Everything you need to know about the largest marketplace for crypto collectibles
- What is OpenSea? +OpenSea is a marketplace for digital goods, including collectibles, gaming items, digital art, and other digital assets that are backed by a blockchain like Ethereum. On OpenSea, you can buy, sell, and trade any of these items with anyone in the world. OpenSea is currently the largest general marketplace for user-owned digital goods, with the broadest set of categories (200 and growing), the most items (over 4 million), and the best prices for new categories of items.
OpenSea is also a decentralized marketplace. Trading on on OpenSea happens through a smart contract, meaning that no central authority ever holds custody of your items. Instead, users store items in their wallet of choice - whether that's a mobile wallet like Trust, Coinbase Wallet, or Opera or an in-browser chrome extension like MetaMask. To better understand the inner workings of the OpenSea marketplace, you can check out the open source code for the OpenSea smart contracts here.
- What can I do on OpenSea? +OpenSea lets you buy and sell crypto collectibles, gaming items, digital art, and other blockchain-based digital items. We have over 200 different projects on our platform, including trading card games like Gods Unchained and CryptoSpells, to collectible games like Axie Infinity and CryptoKitties, to digital art projects like SuperRare and Makersplace, to name systems like ENS (Ethereum Name Service). To start, you can go to your account page to view all of your items. If you want to sell one on the market, simply click into it and click "Sell".
Additionally, OpenSea is often useful for browsing the many types of digital collectibles. We offer a powerful searching and sorting mechanisms that lets you easily find the items you're looking for.
Here's a quick video introduction to selling your first item on OpenSea:
- What exactly are these items I see on OpenSea? +All of the items you see on OpenSea are blockchain-based digital items. Some people like to call them non-fungible tokens, or NFT's. Excitingly, they can be viewed anywhere, exchanged openly, and truly owned in a way that was never before possible in the digital world. You can read a little more about the idea of true digital ownership in this blog post.
- What if I want to create my own item on the blockchain? +Glad you asked! If you're not a developer but you'd still like to mint some items, check out our item minting tool. It'll help you create a contract and mint some items, all without a single line of code. You just fill out the details like names and descriptions and OpenSea handles the rest. Plus, there's no fee! You only pay for the gas.
If you're developing your own smart contract for a game, digital collectible, or some other project with unique digital items on the blockchain, you can easily get added to OpenSea. Just follow the steps in the OpenSea developer documentation. More info on what OpenSea provides can be found on our developer page.
If you're a creator, influencer, or streamer and wish to list something on OpenSea, reach out to us at [email protected].
- How do I use OpenSea? I'd like the full tour!+We've got an article that should answer all of your questions. Check it out on our blog.
- What do I need to use OpenSea?+If you're on a desktop computer, you'll need to install a wallet extension for your browser, such as MetaMask or Dapper. You'll also need to fund your account with Ether in order to purchase an item on OpenSea.
On your mobile device, you'll need to use an Ethereum-compatible mobile browser like Trust, Coinbase Wallet, or Opera.
To learn a little more, check out our getting started page.
- Getting MetaMask+
- Why is my my MetaMask account locked?+If you see a lock screen on your account, you simply need to unlock MetaMask. You can do this by clicking the MetaMask fox in the upper right section of your browser and typing your password.
- I'm trying to buy my first item. Where do I find the address that I should send the ETH to?+You don't need to specify an address. When you click "Buy Now", OpenSea and your wallet will work together to send the ETH from your wallet to the seller. You just have to click "Buy Now" and then approve the transaction that your wallet pops up. OpenSea sends the appropriate info to your wallet, then when you approve the transaction, your wallet broadcasts a transaction to the Ethereum network that sends the ETH to First Edition and the item to you (atomically! either the whole deal happens or none of it does). When the transaction is mined (which usually happens after 30-70 seconds and requires no addiitonal action from you), the item becomes yours and the ETH becomes the seller's.
You just need to click "Buy Now", then approve the transaction using your wallet's interface.
- I'm trying to create my first listing. What are these first two transactions about?+OpenSea never takes custody of your NFTs when you list them for sale. Plus, deals on OpenSea are executed atomically. That is, either the whole deal happens or none of it does. In order to make these features possible, each user must do a little bit of initial setup before making their first listing.
The first transaction creates your "proxy account", which is a tiny little smart contract that only you can use that allows you to interact with our underlying protocol, which is known as the Wyvern Protocol.
The second transaction authorizes your proxy to move a given type of NFT on your behalf (or in the case of older contracts like CryptoKitties, it authorizes your proxy to move just one NFT), so when the NFT sells, it can be transferred to the buyer instantly.
Both of these transactions are free, except for the gas that the Ethereum network requires. And after you complete these initial steps, creating an auction will only require signing a message with your wallet. Once you get these first steps behind you, you'll be able to sell items without paying gas.
- How do I list an item for sale?+In order to list an item, you'll need to find the item on your account page and click on it. On the item detail page, click "Sell". This will walk you through the steps for selling an item. Note that the first time you auction an item, you will need to complete several transactions in order to give the exchange contracts access to your items. After you complete these initial steps, creating an auction will only require signing a message with your wallet. This means that you can auction items without paying gas.
- How does the auction work?+As an OpenSea user, you can either sell an item for a fixed price, a declining price, or an auction. When you list an item for auction, you specify a minimum bid amount (tip: make it low and bidding will be higher and faster!) and a duration. When the duration is over, the highest bidder wins. If no one placed a valid bid, you keep the item and the listing expires automatically.
For declining-price listings, at any point, someone can buy your item at the current price. The current price starts at the start price and gradually decreases over the auction duration until reaching the end price. After the specified duration, the auction will expire and no longer be available for purchase.
- Is there a minimum bid requirement? What happens if someone outbids me at the last second?+Bids must be at least 5% higher than the previous bid. Only bids in the same payment token (e.g. wrapped ETH or DAI) as the auction will be counted towards the winning bid.
If someone bids in the last 5 minutes of an auction, and if their bid exceeds all others, the auction will automatically extend by 5 minutes. This can continue for up to a week of extensions.
- Can I make a listing that doesn't expire?+Currently, all declining-price listings expire when the expiration time is reached. However, if you create a fixed-price listing and don't specify an end price, it will not expire.
- What happens to my item when it's on auction?+For most types of items, the item remains in your wallet while it's on auction! This means it can still be used in the game while it's on auction on OpenSea. (Note that there are still a few item types that require escrow, however)
- I want to make my first listing. What transactions are required?+OpenSea's auctioning system minimizes the number of on-chain Ethereum transactions required to list an item for sale. In fact, once you've completed the preliminary steps, auctioning an item will require no on-chain transaction at all. Here's how it works:
1. For your very first OpenSea auction, you will need to initialize your account with a free (plus gas) on-chain transaction. You only need to do this once!
2. When you auction a new "type" of item (for example, your first CryptoKitty or your first Autoglyph), you will need to complete another free (plus gas) transaction in order to unlock access to that item type. In most cases, you only need to do this once per item type! So, for example, once you've approved access to Autoglyphs, you can auction as many Autoglyphs as you like without having to complete another transaction.
3. Once you've unlocked access to that item type, all auctions will simply require signing a message with your wallet. No gas required!
While there are a few transactions up front, the overall result is a much cheaper, faster experience for the end user.
- What's a private sale and why is there no fee?+A private listing is only fulfillable by one address. When you create a listing, you can set it to "Private" on the page where you set your price and specify the address that's eligible to fulfill it. Other accounts will be able to see that it's on sale and the price you set, but they won't be able to buy it for that price.
The way we see it, OpenSea's primary role is to help sellers find buyers for their digital assets. If you already have a buyer lined up, we're happy to offer a safe and reliable way to make the exchange, free of charge.
- Can I gift or transfer an item to another wallet?+Yes! You can transfer or "gift" an item by clicking the "Gift" button when viewing it.
Gifting an item requires a small amount of gas to pay the Ethereum network, but is not subject to any other fees.
- Can I sell multiple items at once?+Yes! You can sell a "bundle" of items by going to your "My Account" dropdown and selecting "Sell a Bundle". This will allow you to add multiple items in one single auction.
Selling a bundle of items does not require gas! As with other auctions, the first time you sell, you will need to initialize your account with an on-chain transaction. Also, when you auction a new "type" of item (for example, your first CryptoKitty or your first Autoglyph), you will need to complete another free (plus gas) transaction in order to unlock access to that item type.
When someone buys your bundle, he or she will receive all of the items in the bundle, and you'll receive your payment!
- Why can't I list a bundle in my favorite social currency?+$TKN stands in here for the symbol for most ERC20 payment tokens, including social currencies like $HUE or $SKULL. If $TKN is already set up in our system, $TKN should be available on 1) any mixed bundle and 2) any bundle that contains exclusively assets belonging to a collection that allows $TKN. If the bundle contains exclusively assets belonging to a collection that does not permit $TKN, you'll be restricted to the payment tokens permitted on that collection.
- Can I send multiple items to another wallet at once?+Yes! You can transfer or "gift" a bundle of items by going to My Account and selecting "Gift an Item Bundle". This will allow you to add multiple items in one single transfer.
Gifting a bundle of items requires gas, but will only be one transaction if you've already approved the assets for transfer. Each bundle is limited to 30 items due to Ethereum's block gas limit.
Gifting items is not subject to any fees.
- I sold an item but didn't recieve ETH. What happened?+You may have received ETH. The transaction you're looking for just might be a little bit hidden. If you're concerned because you're not seeing an "IN" transaction on Etherscan, check the "Internal Txs" tab on Etherscan. You can also confirm that your balance rose as expected using Etherscan's balance checker tool.
If your ETH balance didn't rise as expcted, consider the possibility that you received WETH instead of ETH. Offers and bids on OpenSea require WETH, so if you accepted an offer or sold an item via English auction, check your WETH balance using the WETH station on the right side of your account page's Offers tab.
- How do I make an offer for an item I want to buy?+See an item you'd like to buy? Simply click the "Make an Offer", which will allow you to specify the price you're willing to buy the item. By bidding like this, you will automatically pay for this item if the owner accepts your offer, unless you cancel it. Read more about how this is useful on our blog.
If you're bidding for the first time, there will be a few preliminary steps before you can submit your offer. While these steps may be a little cumbersome, keep in mind these will only happen once! You will need to:
1. Wrap your ETH with W-ETH (wrapped Ether) using the W-ETH station on the right hand side in the bid flow.
2. Approve the exchange to access your W-ETH.
Both of these will require submitting transactions to the blockchain, but after that submitting an offer does not require gas! Each time you want to bid, you simply sign a message which specifies the price you'd like to purchase the item at.
- What's the difference between ETH and WETH?+WETH is wrapped Ether. It's worth exactly the same as ETH and you can convert between the two currencies any time using the Ethereum Balance widget on the right side of your account page's Offers tab. WETH is necessary for some actions on OpenSea because, unlike ETH, it can be instantly transferred using ERC20's "transferFrom" function. This allows for bids to be accepted by a seller without escrow and without any action from the bidder.
- How many offers can I make at a time?+You can pretty much make as many offers as you want!
For example, say you have 1 ETH in your account. If you wrap that ETH (turning it into 1 WETH), you could bid 1 ETH on CryptoKitty #123, 1 ETH on CryptoFighter #345, 1 ETH on a Mythereum card. However, the moment that any of your bids gets fulfilled, the other bids for 1 ETH on the other items would no longer be valid (since you no longer have enough WETH to fulfill them). When your WETH balance increases enough to cover the offer again, the bid will become valid once again.
- I see some offers on an item I own. How do I sell my item to the highest bidder?+First of all, congrats! You're well on your way to selling an item. Read more about how this is useful on our blog.
You can sell your item to the highest bidder by clicking "Accept Offer" on the highest offer, or by creating an English auction (see Selling below). If you're selling an item for the first time, there will be a few preliminary steps. While these steps may be a little cumbersome, keep in mind they will only happen once!
You will need to:
1. Allow access to offers. You'll need to initialize your account in order to sell items. This will be an on-chain transaction. Fortunately, this only needs to be done once!
2. Approve access to the item type. This will require another on-chain transaction, but only needs to be done once per item type (i.e, once for CryptoKitties, once for Etheremon, etc.)
After completing these two preliminary steps, you can then complete an on-chain transaction to sell your item! Once you complete the transaction, you will have W-ETH in your account. You can either leave your W-ETH as is (it's useful for bidding on other items), or you can turn it back into Ether on the Offers section of your account page.
- Someone offered me DAI or USDC for my item... what is this currency?+Congratulations! DAI and USDC are ERC-20 tokens with some remarkable qualities. First of all, they're stablecoins, which means that their value is protected against some of cryptocurrency's notorious price swings. This is not the case for all stablecoins, but each is pegged to the price of one US Dollar. They won't always have that exact value, but you can rest assured that they will stay within a few percentage points of that mark.
Dai (DAI) is a decentralized stablecoin with smart contracts backed by collateral. For more information, check out this interview from Dai's creator Maker about how Dai maintains its price.
USD Coin (USDC) was crafted by the CENTRE consortium, founded by Circle and Coinbase. Users in the U.S. can easily convert their USD to USDC on Circle or Coinbase for free and transfer it to their wallet of choice to complete their purchase on OpenSea.
In short, stablecoins are tokens worth a dollar each. When you see DAI or USDC, think dollar.
So, if you're convinced of the value of stablecoins (we are!), you can sell your item to the highest bidder by clicking "Accept Offer" on the highest offer. If you're experienced at selling on OpenSea using ETH, it'll be a familiar process. If it's your first time selling an item, you'll need to go through a few preliminary steps:
1. Allow access to offers. You'll need to initialize your account to sell items. This requires an on-chain transaction, so you'll have to pay some gas. Fortunately, it only needs to be done once!
2. Approve access to the item type. This will require another on-chain transaction, but it only needs to be done once per item type (i.e, once for Axies, once for Etheremon, etc.)
3. Complete a final on-chain transaction to sell your item. Once you complete the transaction, you'll have DAI or USDC in your account. What you do from there is up to you!
- How do I get notified when someone bids on my items?+We'll email you whenever someone bids on an item you own. Just make sure you have an email set in your Account Settings.
- I'm making a small bid. Why do I see such a large amount of WETH in my wallet popup?+To make offers or place bids, you need to approve WETH (or a whichever ERC-20 token you're using). While this action requires a transaction on the Ethereum network and costs a little bit of gas, it's not a transfer.
It simply authorizes the instantaneous transfer of WETH later, at the moment your offer is accepted or at the moment that your winning bid is matched up with the auction's sell order.
Most dapps, including OpenSea, ask you to approve all of the WETH in your wallet up front so that you don't have to approve more every time you make a larger offer or bid. That way, after the first approval, you can make all the bids and offers you want and you won't ever have to do another approval transaction for that currency.
- I made an offer but it wasn't accepted. When will I get my refund?+
Making and Accepting Offers
- What's a bounty?+Bounties incentivize matchmakers to pair up sellers with buyers. Say my friend Harry Hunter knows a lady named Sally Seller (who recently listed NFT X) and a guy named Bill Buyer who wants to buy NFT X. But Sally and Bill don't know each other. Harry can send an OpenSea link for NFT X to Bill with
?ref=HARRY'S_ADDRESS_OR_USERNAME_HEREappended onto the end of it and when Sally buys the item, Harry earns between 1% and 2.5% of the total sale price.
If you're a seller and you want to learn how to leverage the OpenSea affiliate program, read 'How do I increase the bounty on my listing?'. If you're a dapp enthusiast interested in earning bounties, skip down to the 'How do I earn bounties?' section. If you're a developer, we've got solutions of all sorts for you in the last three sections.
To read more about Bounties and see screenshots for reference, check out our article on the subject.
- How do I increase the bounty on my listing?+Just click 'Edit' in the Bounties section of the asset listing flow, then drag the slider up.
It doesn't cost you anything to raise the bounty percentage--the funds for the bounty hunters come from the 2.5% that OpenSea would otherwise collect as a fee on successful sales. The higher the bounty, the greater the incentive for bounty hunters to find a buyer for your listing.
- How do I earn bounties?+First, go to your account page, then select the 'Referrals' tab. If you haven't signed up for an account yet, fill in the fields and click 'Save.' Sign the message to confirm the information, then click 'Join Now' to join the affiliate program. Then, find a listing to refer.
Once you've selected a listing that you believe you can find a buyer for, navigate to its page and click the bounty bar at the bottom of the listing's price detail section. Then, click 'Copy' to access your referral link. Pro tip: you can also turn any asset link into a referral link by manually appending
Now that you've got your referral link, you're ready to start sharing it on Discord, Twitter, and other social media outlets. Just be sure to maintain good etiquette; rules about referral links still apply to NFTs!
When a buyer enters OpenSea through your referral link, OpenSea will automatically pay out the appropriate percentage of the sale price of the next item the buyer purchases. Even if it's not the item you linked them to, you'll get a percentage of that sale price, determined by the seller's configuration. It'll be paid out in whatever token the item was listed in, unless it was listed in WETH, and then you'll receive ETH. Depending on traffic levels, payouts sometimes take 15 minutes or so to process. But don't lose hope! Your bounty will arrive shortly.
However, you can only earn one referral from each address. The second time you refer a given user, you won't earn a bounty. So, if you refer 0x1, 0x2, and 0x3, you'll get three payments. But if you refer 0x1, 0x2, and then 0x2 again, you'll only get two payments.
- Can I earn bounties by embedding a marketplace on my site?+Yes! If you run a website, OpenSea makes it easy to embed a storefront and refer buyers in bulk. Just select a category from the sidebar on the left, click the '••• More' button, and select 'Embed This Page' from the dropdown. When you sign up for the affiliate program and add the modal's code snippet to your site, you'll receive a bounty whenever you refer a sale.
- Can I earn bounties by processing sales through the SDK?+Yes! To learn how to create a custom marketplace using our SDK, check out our documentation and our example dapp, the Ship's Log. Once you've got a marketplace up and running, you can simply sign up for the affiliate program and feed your address as an additional parameter into
seaport.fulfillOrder. You'll receive a portion of each sale you process this way.
If you've got questions about building a marketplace or earning bounties through your existing marketplace, please chat with us in the #developers channel of our Discord server. We love talking about our SDK, and we're getting pretty good at answering questions from engineers of all skill levels.
- Can I earn bounties if I built a wallet and I send users to OpenSea?+Yes! If you're building a wallet and you're already directing users to OpenSea, sign up for the affiliate program and add
?ref=WALLET_DEVELOPER_ADDRESS_HEREonto OpenSea asset links. You'll start earning bounties as soon as users start making purchases on OpenSea.
- What is the preferred affiliate program? How can I get signed up?+If you're an NFT-related-content creator or if you run a site linking to your collections or items on OpenSea, you might be eligible for our preferred affiliate program, which allows you to earn repeat bounties from purchases made by the same user. Contact us in Discord for more info!
- How long does it take for a bounty payment to process?+It usually takes around 15 minutes, but it might take as much as an hour. If you referred a buyer to an item, but didn't receive a payment, it might be the case that you've referred that buyer before. Each referrer can only earn one bounty per buyer referred. The second time you refer a given user, you won't earn a bounty. So, if you refer 0x1, 0x2, and 0x3, you'll get three payments. But if you refer 0x1, 0x2, and then 0x2 again, you'll only get two payments.
If you're sure that you should have gotten a bounty, but you haven't received it, please contact us in Discord.
- Help! I was able to auction things before, but it's not working anymore!+Occasionally, Metamask will start having issues submitting transactions, causing the OpenSea flows to fail. We've found that the best solution for this is to kill the Metamask extension in Chrome. Before doing this, ensure that you have backed up your Metamask seed phrase. Once you've backed up your seed phrase, try the following:
1. In Chrome, go to the "window" menu, and click "Task Manager".
2. Find the Metamask processes (you can sort alphabetically) and hit "End Process".
2. When the white Chrome notification pops up that says "Click this ballooon to reload the extension", click it to reload Metamask. (If you're not able to click the white notification in time, simply go to chrome://extensions and click "Reload").
3. Then give the flow on OpenSea another try.
If you're still having issues contact us on Discord.
- I bought something on OpenSea. It's in my OpenSea account but it's not showing up in the game where it's used.+In these cases, we recommend reaching out to the game's support team. If the item is showing up properly on your OpenSea account, the blockchain has properly recorded its transfer into your account. However, the game may not have properly updated to reflect the new ownership (hence we recommend contacting their support team).
- I'm getting the error: "Unable to match offer with auction. Please restart your wallet/browser and try again!"+In some rare cases, MetaMask's node will get out of sync with the blockchain, which will prevent you from completing certain actions. If this error persists, we recommend switching your RPC provider to a different Ethereum node. To do this, go to MetaMask and click on "Main Ethereum Network". Then switch to "Custom RPC". You'll need to get a custom URL from us on Discord.
- I'm getting the error: "Error matching this listing: Unable to match offer with auction. Please contact the maker or try again later!"+This error results from an issue with your device's internal clock. Try resetting your computer's clock. If it's slipped even 30 seconds, it can interfere with your ability to accept offers and make purchases.
Alternatively, try doing the problematic action using Trust Wallet or a different computer. If the action still fails on more than one device, please contract us on Discord.
- I'm trying to create a listing, but I'm getting the error: "You do not own this asset." I own it, though!+Typically, switching to the Rinkeby network and back to mainnet will resolve this issue.
- I'm using a hardware wallet. I can't make offers or create listings. Why?+MetaMask and hadrware wallets just don't play nicely together when you're trying to make offers and create listings. If you're using a Trezor, we don't have a solutiuon for you. Sorry. We're working with the MetaMask to resolve the underlying issue.
But if you're using a Ledger and you see an error along the lines of, "Ledger: The signature doesn't match the right address," we recommend using SpaceSuit, a browser extension wallet like MetaMask. It's designed specifically to make dapps and hardware wallets function smoothly together. Using a Ledger device with SpaceSuit will be a lot using a Ledger device with MetaMask, except that when it's time to sign an offer or a listing, you shouldn't get an error.
And if your assets aren't in the first address generated by your seed phrase, check out SpaceSuit's documentation on accessing the other addresses.
- Why am I stuck on the loading screen when I use Brave?+Brave recently released a native crypto wallet that interferes with MetaMask, which in turn causes indefinite loading in some places on OpenSea. You can go into the settings and turn Brave's native wallet off. After that, things should start working as expected. You may also need to restart Brave or MetaMask.
Settings > Extensions > Brave Wallet
- I can't switch between MetaMask accounts. Why?+One of the latest versions of MetaMask (7.7.0) included major changes to how address switching works. We're going to change some stuff on our side to try to mitigate the disruption. In the meantime, read on for a partial solution.
The unexpected behavior: I click the icon in the top right corner of the popup and switch from account 1 to account 5. While the extension remains open, it keeps showing account 5. When I close the extension popup and reopen it, I'm back in account 1.
If that's the behavior you're getting, try the following.
Open the "..." menu (Account Options). Next, click "Connected Sites" and disconnect from OpenSea. Then, navigate to your account page or reload it if you're already there. OpenSea will ask you to connect your wallet. Click to connect. A MetaMask tab will open and ask you to choose which account to connect. Select the account you want to use and click "Submit." You should now be connected to the new account.
- Is there a way I can tokenize my art?+Yes! We have a no-code tool for creating your own contract and minting your own tokens: the OpenSea Storefront Manager
OpenSea’s Storefront Manager allows you to create a contract and an OpenSea Storefront, all without a single line of code. All you need is some content, a wallet, and a little bit of ETH to pay for gas. There’s no fee beyond what the Ethereum network charges.
- So if I create an item, does it become an NFT?+Yes! When you create a new storefront using our Storefront Manager, you deploy a new contract. And when you create a new item, you're minting an NFT on that contract.
- Why does it ask for an external link?+Some artists like to link to their homepage, or to a page that's specific to the piece of art with more info or a higher resolution version of the image.
- What is markdown syntax?+Markdown allows you to use special characters to indicate that a line should be bold, italic, etc. You can just enter normal text if you'd like. But if you're feeling ambitious, check out this Markdown reference.
- How do I add existing tokens from my collection to my storefront?+It's not possible to add existing tokens to your storefront. The Storefront Manager allows you to create a new contract and mint new tokens. It does not allow you to create a new collection of arbitrary tokens, whether you own them or not.
- How do I sell the items I made?+Just like any other item! Clicking on one of your newly minted items, click the "Sell" button, configure your listing, then click the "Post your listing" button.
For more information, check out the section on selling above.
- Why isn't my contract accessible in the sidebar or the search bar?+That’s the default state of all new contracts on OpenSea. We employ a concept that we call safelisting. When a dapp gets safelisted, it appears in the sidebar and becomes searchable in the main search bar.
Safelisting is discretionary, but we use a few key metrics to inform the decision: the project’s community engagement on Discord and Telegram, historical volume of sales on OpenSea, the project’s reach on Twitter and other social media, the novelty of the tech, and the pace of development, among others. If you put together a brief report on your project, focusing on the metrics enumerated above, and send it to [email protected] we’d be happy to review it.
- More developer FAQs+Please visit the Developer FAQ's section of our developers portal for a comprehensive list of developer FAQ's.
- Is OpenSea just aggregating auctions from other marketplaces?+While OpenSea does include data from some game marketplaces (like CryptoKitties), most of the auctions you'll see on OpenSea are made through our own auctioning system. For many games, we act as the primary marketplace for buying and selling the game items.
- I'm trying to transfer an item. Why is the recipient address always replaced in MetaMask with the token contract address?+It's just a quirk of how token contracts work. When you transfer a token, you don't send the transaction to the address who will receive the token. You send the transaction to the token contract. You tell it, "please transfer token ID 123 to address 0x123abc". The token contract is the target of the transaction and the token ID and the recipient address are arguments to the token contract's transfer function.
In less technical terms, it's like mailing a note to the bank saying "please transfer one dollar from my account to the specified recipient" rather than mailing a dollar to the end recipient. The recipient's name is inside the envelope, but the address on the outside of the envelope is the bank's.
- Do you charge transaction fees?+Yes, we take 2.5% from the price of a successful sale. The original creator of the item (such as the developer of the game) can opt to take a fee on the final transaction as well.
There's no fee to list items or buy items. But when you list an item, the sidebar on the right (or the section on the bottom on mobile) will tell you fee that will be deducted when the item sells. E.g. if OpenSea takes 2.5% and the creator takes 4%, the total fee will be 6.5% of the final sale price.
- What does the blue checkmark mean?+The blue checkmark next to usernames means that OpenSea has verified that the owner of that wallet address is who they claim to be.
Verified checkmarks are available for accounts that OpenSea deems to be needing verification (due to public attention and other factors). If you'd like to be verified, please contact us in Discord!
- Is OpenSea safe?+OpenSea has a strong track record as a safe marketplace for unique blockchain-based assets. We've had over 40,000 ETH of volume pass through our smart contract and many thousands of successful sales. We've acted as the primary marketplace for several large games, including Etheremon Adventure, My Crypto Heroes, CryptoVoxels, ChainBreakers, Ether Kingdoms, and CryptoBeasties -- as well as a secondary market for CryptoKitties, MLB Crypto, Axie, and a host of others.
For the more technically savvy: we leverage the Wyvern Protocol, an audited, battle-tested set of smart contracts. Wyvern is a decentralized exchange system that creates a personal proxy for each user. We don't control the proxies that get created, and you have to approve access to each ERC721 contract individually. Once the contract is approved, the logic of the exchange contract only allows it to transfer an asset from your proxy only if A) you have signed an order indicating you wish to sell that item, and B) it is properly matched by a buyer paying the appropriate funds. So not only does your asset not leave your wallet until it is sold, it is only allowed to be swapped if an order you create is properly matched.
- What exactly happens when I list something for auction?+When you list one of your collectibles for auction, you'll sign a message broadcasting that you're willing to sell the item for a specific price. Once your item has been placed for auction, a buyer can buy your item at the current auction price. At that time, the proper amount of money will be transferred to you and the item will be transferred to the buyer. Excitingly, this happens atomically -- meaning there is no risk that you don't receive payment or that the buyer doesn't receive the item.
- What's the story with support for ERC-20s like MANA and DAI?+When we first built OpenSea, we decided to construct the experience around Ethereum, as a dapp platform and as a currency. It was the simplest option. Because most users already had some ETH, if only to pay gas, it provided an economic lingua franca. And it allowed us to streamline a new and unfamiliar buying experience. But all along, we've been excited about the entire token economy and we intend to grow with the maturing ecosystem and user base.
Now, with support for ERC-20 tokens like MANA and DAI, we're doing exactly that. In addition to allowing users to spend the currencies they already have, it will allow developers to offer NFTs for sale denominated in the dapp's in game currency. You still get to use all the OpenSea features you've come to know, but now with more flexibility.
You'll find some items listed for sale in an ERC-20 token. You can buy them immediately by paying in the specified currency, like making a purchase with ETH. If you don't have any of the seller's specified currency (and have no desire to acquire any), you can make an offer in the currency of your choice by clicking the 'Make Offer' button and selecting your preferred currency from the dropdown next to the entry field. For more about how powerful bidding on OpenSea is, check out our blog post.
To list an item for sale in the ERC-20 of your choice, click 'Sell' on the item's page, select a token from dropdown next to the price entry field, specify your desired price, then click 'Post Your Listing'.
- Do you issue refunds?+Since transactions on the blockchain are irreversible, we cannot provide refunds. We have no ability to cancel, revert, or modify any transactions on the Ethereum network.
- How can I set up a webhook?+You can receive notifications in Discord about the activity for any contract on OpenSea. To create a channel in your Discord server that shows the activity for Autoglyphs, make a new text channel in your Discord server and name it something like '#opensea-autoglyphs', then hover over it and click the gear icon. Select the webhooks option from the menu and click "Create webhook" to make a new webhook. Name it something like "OpenSea" and copy the link that Discord provides.
Then take that link to https://opensea.io/assets/autoglyphs, click the "...More" button in the top right corner and select the "Subscribe" option. Paste the link into the modal that pops up and click "Add webhook". You'll need to sign a message to complete the process.
To test that your Autoglyhs webhook is set up correctly, try making a bid on an Autoglyph and checking whether it shows up in your new '#opensea-autoglyphs' channel. If you have any questions or run into any issues, please contact us in Discord!
You can adapt this process for contracts other than Autoglyhs and platforms other than Discord. We use the Discord POST body format, but you could use the OpenSea webhook system in your own app if you'd like. For more info, please ping us in the #developers channel of our Discord server.