This SDK helps developers get started with the on-chain tools provided by Metaplex. It focuses its API on common use-cases to offer a smooth developer experience.
Please check the Sample App.
The library is now available through JitPack.io
First, add the JitPack repository to your build:
repositories {
...
maven { url 'https://jitpack.io' }
}
Then add the dependency to the 'build.gradle' file for your app/module:
dependencies {
...
implementation 'com.github.metaplex-foundation:metaplex-android:{version}'
}
We are constantly pushing new updates and adding new features. These fetures are incubated in feature branhces before being merged into our development and primary release branches (TODO: document git flow branching strategy). To grab the latest snapshot relase of any branch:
dependencies {
...
implementation 'com.github.metaplex-foundation:metaplex-android:{branch name}-SNAPSHOT'
}
To test out our latest semi-stable code, use the latest development snapshot build as follows:
dependencies {
...
implementation 'com.github.metaplex-foundation:metaplex-android:develop-SNAPSHOT'
}
You can also add the dependency directly from GitHub. We recommend using the GitHub recommended way to load Artifacts. First, get a GitHub Token from your account settings.
Inside settings.gradle add a maven repository:
repositories {
...
maven {
name = "GitHubPackages"
url = "https://github.com/metaplex-foundation/metaplex-android"
credentials {
username = "<YOUR_GITHUB_USERNAME>"
password = "<YOUR_GITHUB_TOKENS>"
}
}
}
Then at your build.gradle:
dependencies {
...
implementation 'com.metaplex:metaplex:+' // Set version
implementation 'com.solana:solana:+' // Required
}
After that, perform Gradle sync.
- Android API 21+
The entry point to the Android SDK is a Metaplex instance that will give you access to its API.
Set the SolanaConnectionDriver and set up your environment. Provide a StorageDriver and IdentityDriver. You can also use the concrete implementations OkHttpSharedStorageDriver for OKHttp and ReadOnlyIdentityDriver for a read-only Identity Driver.
You can customize who the SDK should interact on behalf of and which storage provider to use when uploading assets. We might provide a default and straightforward implementation in the future.
val ownerPublicKey = PublicKey("<Any PublicKey>")
val solanaConnection = SolanaConnectionDriver(RPCEndpoint.mainnetBetaSolana)
val solanaIdentityDriver = ReadOnlyIdentityDriver(ownerPublicKey, solanaConnection.solanaRPC)
val storageDriver = OkHttpSharedStorageDriver()
val metaplex = Metaplex(solanaConnection, solanaIdentityDriver, storageDriver)Once properly configured, that Metaplex instance can be used to access modules providing different sets of features.
Currently, there are 3 modules available: tokens, nft, and auctions
- The Token module is accessed via the
tokensproperty, and is used to interact with Metaplex Tokens (fungible tokens). - The NFT module can be accessed via the
nftproperty. From this module, you will be able to find, create and update NFTs (with more features to come). - The Actions module can be accessed via the
auctionsproperty and is used to interact with Metaplex Auction House Programs.
The Token module can be accessed via Metaplex.tokens and provide the following methods. Currently we only support read methods.
All methods are suspend funs and require a coroutine scope to be called. This gives the caller ultimate flexibility on thread handling, asynchronous operations, cancellation, etc.
The findByMint method accepts a mint public key and returns a Token object..
metaplex.tokens.findByMint(mintPublicKey).apply {
onSuccess { token ->
...
}
onFailure { error ->
...
}
}The Token module can be accessed via Metaplex.tokens and provide the following methods. Currently we only support read methods.
All methods are suspend funs and require a coroutine scope to be called. This gives the caller ultimate flexibility on thread handling, asynchronous operations, cancellation, etc.
The findByMint method accepts a mint public key and returns a Token object..
metaplex.tokens.findByMint(mintPublicKey).apply {
onSuccess { token ->
...
}
onFailure { error ->
...
}
}The NFT module can be accessed via Metaplex.nft and provide the following methods. Currently we only support read methods. Writing and creating NFTs will be supported on the future.
findByMint(mint)findAllByMintList(mints)findAllByOwner(owner, callback)findAllByCreator(creator, position = 1)findAllByCandyMachine(candyMachine, version = 2)
All methods are suspend funs and require a coroutine scope to be called. This gives the caller ultimate flexibility on thread handling, asynchronous operations, cancellation, etc.
Note that previously, all the methods returned a callback:
findByMint(mint, callback)findAllByMintList(mints, callback)findAllByOwner(owner, callback)findAllByCreator(creator, position = 1, callback)findAllByCandyMachine(candyMachine, version = 2, callback)
These methods are still available, though they have been marked as deprecated and will likely be refactored or removed in a future release.
The findByMint method accepts a mint public key and returns the NFT object.
metaplex.nft.findByMint(mintPublicKey).apply {
onSuccess {
...
}
onFailure {
...
}
}The returned Nft object will NOT contain JSON data. It will only contain on-chain data. If you need access to the JSON off-chain metadata, the call requires the metaplex object.
nft..metadata(metaplex).apply {
onSuccess {
...
}
onFailure {
...
}
}Similarly, the MasterEditionAccount account of the NFT will also be already loaded, and if it exists on that NFT, you can use it like so.
val masterEdition = nft.masterEditionAccountDepending on the MasterEditionAccount version, it can return v1 or v2 enums.
You can read more about the NFT model below.
The findAllByMintList method accepts an array of mint addresses and returns an array of Nfts. However, null values will be returned for each provided mint address that is not associated with an NFT.
metaplex.nft.findAllByMintList(listOf(mintPublicKey, mintPublicKey)).apply { result ->
result.onSuccess { nfts ->
val nftList = nfts.filterNotNull() // useful to remove null
...
}
}NFTs retrieved via findAllByMintList will not have their JSON metadata loaded because this would require one request per NFT. This could be inefficient if you provide a long list of mint addresses. Additionally, you might want to fetch these on-demand, as the NFTs are displayed on your web app, for instance.
Thus, if you want to load the JSON metadata of an NFT, you may do this like so.
nft..metadata(metaplex).apply { result ->
result.onSuccess {
...
}.onFailure {
...
}
}We'll talk more about these tasks when documenting the NFT model.
The findAllByOwner method accepts a public key and returns all Nfts owned by that owner's public key.
metaplex.nft.findAllByOwner(ownerPublicKey).apply { result ->
result.onSuccess { nfts ->
val nftList = nfts.filterNotNull() // useful to remove null
...
}.onFailure {
...
}
}Similar to findAllByMintList, the returned Nfts will not have their JSON metadata. This method, along with findByMint, is used in the Sample App.
All the methods above either return or interact with an Nft object. The Nft object is a read-only data representation of your NFT that contains all the information you need at the top level.
You can see its full data representation by checking the code but here is an overview of the properties that are available on the Nft object.
class NFT(
val metadataAccount: MetadataAccount, // inherited from Token
val masterEditionAccount: MasterEditionAccount?
) {
// Inherited Token properties
val updateAuthority: PublicKey = metadataAccount.update_authority
val mint: PublicKey = metadataAccount.mint
val name: String = metadataAccount.data.name
val symbol: String = metadataAccount.data.symbol
val uri: String = metadataAccount.data.uri
val sellerFeeBasisPoints: Int = metadataAccount.data.sellerFeeBasisPoints
val creators: Array<MetaplexCreator> = metadataAccount.data.creators
val primarySaleHappened: Boolean = metadataAccount.primarySaleHappened
val isMutable: Boolean = metadataAccount.isMutable
val editionNonce: Int? = metadataAccount.editionNonce
val tokenStandard: MetaplexTokenStandard? = metadataAccount.tokenStandard
val collection: MetaplexCollection? = metadataAccount.collection
...
}As you can see, some of the properties are loaded on demand. This is because they are not always needed and/or can be expensive to load.
To load these properties, you may run the metadata properties of the Nft object.
nft.metadata(metaplex: self.metaplex).apply { result ->
result.onSuccess { metadata ->
...
}.onFailure { error ->
...
}
}NOTICE: A friendly reminder that this SDK is currently WIP/beta, and the Auction House module in particular is highly experimental. This module is still under development, and has not been fully tested. Try it out, expect bugs, and give us feedback (or open a PR! ;D).
The Metaplex Auction House protocol allows anyone to implement a decentralized sales contract and accept ay SPL token they desire.
The Auctions module can be accessed via Metaplex.auctions and provide the following methods. Currently we only support read methods. Auction House creation, and the ability to interact with and create bids and listings will be supported in the future.
findAuctionHouseByAddress(address)findAuctionHouseByCreatorAndMint(creator, treasuryMint)- more coming soon!
All methods are provided as composable suspending functions to provide more flexibility and compatibility in your application.
Note: These suspend functions provided by the Auctions API are an architectural change for the library. We have previously only provided async-callback methods. We highly recommend that everyone migrate to the new suspending functions, however we have also provided async-callback implementations of the available methods. Note that these methods are provided as a interim and may be deprecated in the future:
findAuctionHouseByAddress(address, callback)findAuctionHouseByCreatorAndMint(creator, treasuryMint, callback)
The findAuctionHouseByAddress method accepts a public key and returns an AuctionHouse object, or an error if no AuctionHouse was found for the given address.
val theAuctionHouse: AuctionHouse? = metaplex.auctions.findAuctionHouseByAddress(addressPublicKey).getOrNull()The findAuctionHouseByCreatorAndMint method accepts a public key and returns an AuctionHouse object, or an error if no AuctionHouse was found for the given address.
val theAuctionHouse: AuctionHouse? = metaplex.auctions.findAuctionHouseByCreatorAndMint(creatorPublicKey, mintPublicKey).getOrNull()The returned AuctionHouse model will contain details about the Auction House account on chain. In the future, this model will be used to construct an AuctionHouseClient instance to interact with the auction and perform trades.
The AuctionHouse objects that are returned by the auctions module can be used to create a new AuctionHouseClient instance that is used to interact with that specific Auction House.
val myAuctionHouseClient = AuctionHouseClient(theAuctionHouse, metaplex)Alternatively, the auction house client can be initialized with your own connection and identity drivers:
val myAuctionHouseClient = AuctionHouseClient(theAuctionHouse, myConnectionDriver, myIdentityDriver) The Auction House Client provides the following methods:
list(mint, price, authority, auctioneerAuthority, printReceipt)bid(mint, price, authority, auctioneerAuthority, printReceipt)executeSale(asset, listing, bid, auctioneerAuthority, bookeeper, printReceipt)cancelListing(listing, mint, authority)cancelBid(bid, mint, authority)
The list method accepts a public mint key and price, and optionally accepts a specified authority, auctioneer, and a boolean to print the listing receipt. This method returns a Listing object, or an error if the listing could not be created for any reason (see returned error message).
val myListing = myAuctionHouse.list(mintPublicKey, price)
// or with optional parameters
val myListing = myAuctionHouse.list(
mintPublicKey,
price,
auctionHouseAuthorityPublicKey,
auctioneerAuthorityPublicKey,
printReceipt
)The returned Listing object will contain details about the listing that was created and can be used to execute a sale if a matching Bid is obtained.
The bid method accepts a public mint key and price, and optionally accepts a specified authority, auctioneer, and a boolean to print the bid receipt. This method returns a Bid object, or an error if the bid could not be created for any reason (see returned error message).
val myBid = myAuctionHouse.bid(mintPublicKey, price)
// or with optional parameters
val myBid = myAuctionHouse.bid(
mintPublicKey,
price,
auctionHouseAuthorityPublicKey,
auctioneerAuthorityPublicKey,
printReceipt
)The returned bid object will contain details about the bid that was created and can be used to execute a sale if a matching Listing is obtained.
The executeSale method requires 3 objects: an Asset, a Lsiting, and a Bid. A specified auctioneer, bookkeeper, and a boolean to print the sale receipt can be optionally included. This method returns a Purchase object, or an error if the listing could not be created for any reason (see returned error message).
val purchase = myAuctionHouse.executeSale(asset, listing, bid)
// or with optional parameters
val purchase = myAuctionHouse.executeSale(
asset, listing, bid,
auctioneerAuthorityPublicKey,
bookkeeperPublicKey,
printReceipt
)The returned Purchase object will contain details about the sale that was executed.
The cancelListing method is used to cancel an existing listing, and requires a Listing object, and an asset mintKey. Optionally, an Auction House authority can also be included. This method returns the transaction response, or an error if the transaction failed for any reason (see returned error message).
myAuctionHouse.cancelListing(listing, mintPublicKey, authorityPublicKey).apply {
onSuccess {
// cancel transaction was successful
}
onFailure {
// handle error
}
}Much like the cancelListing, the cancelBid method is used to cancel an existing Bid, and requires a Bid object, and an asset mintKey. Optionally, an Auction House authority can also be included. This method returns the transaction response, or an error if the transaction failed for any reason (see returned error message).
myAuctionHouse.cancelBid(bid, mintPublicKey, authorityPublicKey).apply {
onSuccess {
// cancel transaction was successful
}
onFailure {
// handle error
}
}The current identity of a Metaplex instance can be accessed via metaplex.identity() and provide information on the wallet we are acting on behalf of when interacting with the SDK.
This method returns an identity object with the following interface. All the methods require a Solana API instance.
interface IdentityDriver {
val publicKey: PublicKey
fun sendTransaction(transaction: Transaction, recentBlockHash: String? = null, onComplete: ((Result<String>) -> Unit))
fun signTransaction(transaction: Transaction, onComplete: (Result<Transaction>) -> Unit)
fun signAllTransactions(transactions: List<Transaction>, onComplete: (Result<List<Transaction?>>) -> Unit)
}The implementation of these methods depends on the concrete identity driver being used. For example, use a KeypairIdentity or a Guest(no public key added)
Let’s quickly look at the concrete identity drivers available to us.
The GuestIdentityDriver driver is the simplest identity driver. It is essentially a null driver that can be useful when we don’t need to send any signed transactions. It will return failure if you use signTransaction methods.
The KeypairIdentityDriver driver accepts an Account object as a parameter.
The KeypairIdentityDriver driver accepts a PublicKey object as a parameter. It's a read-only similar to the GuestIdentity, but it has a provided PublicKey. It will return failure if you use signTransaction methods.
You may access the current storage driver using metaplex.storage(), which will give you access to the following interface.
interface StorageDriver {
suspend fun download(url: URL): Result<NetworkingResponse>
}Currently, it's only used to retrieve JSON data off-chain.
This will use OkHttp networking, the most popular Android networking implementation library. It might be the most useful implementation.
This will use the returned Empty Data object with size 0.
As mentioned above, this SDK is still in very early stages. We plan to add a lot more features to it. Here’s a quick overview of what we plan to work on next.
- New features in the NFT module.
- Upload, Create NFTs to match JS-Next SDK.
- More documentation, tutorials, starter kits, etc.
By default, the library tests will run against the Solana devenet RPC endpoint. Testing in this configuration can be problematic due to rate limiting, and it is therefore recommended to use your own RPC endpoint. This can be either a local validator node, or a dedicated RPC provider.
To specify your own RPC endpoint to be used for testing, you can add a gradle property with the name rpcUrl to the project/configuration. The test suite will attempt to use the value of rpcUrl if it is present.
For example, to run all tests using a custom RPC endpoint from the command line:
./gradlew test -PrpcUrl=http://my.rpc.endpoint/custom
If using Android Studio/Idea, this can also be added as a saved run configuration for easy access within the IDE UI.
Alternatively, to use the default local validator endpoint (http://127.0.0.1:8899), you can simply set the following gradle property:
localValidator=trueWe are continuing to improve our testing framework and will likely have more configuration options and better handling of devnet testing in the future.
We encourage anyone and everyone to contribute to this SDK by opening a pull request.
A few guidelines for contributor PRs
- target the
developbranch, or a relevant feature branch. PRs should not target themainbranch. - should include a detailed and up to date description, and adhere to our pull request template
- ensure that all unit tests are passing locally before submitting your PR for review
These guidelines serve to expedite our review of community contributions. We greatly appreciate your cooperation!
The SDK is heavily inspired by the JS-Next SDK. The objective of this is to have one Metaplex-wide interface for all NFTs. If you use the JS-Next SDK, this SDK should be familiar.