¿Qué es un Mint con Interés?
La extensión de mint InterestBearingConfig del Programa de Extensiones de
Token permite que un mint almacene una tasa de interés anualizada directamente
en la cadena.
Los tokens con interés no añaden más tokens a las cuentas de tokens con el tiempo. La cantidad de tokens almacenada en cada token account permanece igual hasta que una instrucción del programa de tokens la cambie, como acuñar, transferir o quemar.
A medida que pasa el tiempo, la cantidad UI calculada con interés puede aumentar aunque la cantidad de tokens y el suministro de tokens permanezcan iguales.
Cómo se Calculan los Cambios de Tasa Históricos
InterestBearingConfigalmacenainitialization_timestamp,pre_update_average_rate,last_update_timestampycurrent_rate.amount_to_ui_amountcalcula la cantidad UI en dos pasos: primero calcula el interés desde la inicialización hastalast_update_timestampusandopre_update_average_rate, luego calcula el interés desdelast_update_timestamphasta la marca de tiempo actual usandocurrent_rate.- Cuando
UpdateRatese ejecuta,process_update_ratellama atime_weighted_average_ratey actualizapre_update_average_ratea un nuevo promedio histórico ponderado por tiempo, luego registra un nuevolast_update_timestampycurrent_rate. - Después de los cambios de tasa a lo largo del tiempo, los cambios anteriores
están representados por
pre_update_average_rate, mientras que el período desdelast_update_timestamphasta el tiempo actual se calcula concurrent_rate.
Cómo Crear y Usar Tokens con Interés
Para crear y usar tokens con interés:
- Calcule el tamaño del mint account y el rent necesario para el mint y la
extensión
InterestBearingConfig. - Cree el mint account con
CreateAccount, inicialiceInterestBearingConfige inicialice el mint conInitializeMint. - Acuñe tokens como de costumbre.
- Use
UpdateRatepara cambiar la tasa actual del mint con el tiempo. - Convierta cantidades de tokens en una cantidad UI con interés con
AmountToUiAmounto métodos auxiliares que obtengan el mint account y el sysvar del reloj, luego calculen la cantidad UI sin enviar una transacción.
Conversión de cantidad de UI fuera de cadena y en cadena
La ruta del asistente fuera de cadena obtiene la mint account y el sysvar del
reloj, luego calcula la cantidad de UI localmente sin enviar una transacción.
La ruta en cadena utiliza AmountToUiAmount, que se ejecuta en el Token
Program y devuelve la cantidad de UI en los datos de retorno de la
transacción. AmountToUiAmount puede enviarse en una transacción o
simularse.
Calcular el tamaño de la cuenta
Calcula el tamaño de la mint account para la mint base más la extensión
InterestBearingConfig. Este es el tamaño utilizado en CreateAccount.
Calcular el rent
Calcula el rent utilizando el tamaño necesario para la mint más la extensión
InterestBearingConfig.
Crear la mint account
Crea la mint account con el espacio y los lamports calculados.
Inicializar InterestBearingConfig
Inicializa la extensión InterestBearingConfig en la mint.
Inicializar la mint
Inicializa la mint con InitializeMint en la misma transacción.
Crear una token account y acuñar tokens
Crea una token account para la mint, luego acuña tokens en esa token account.
Calcular la cantidad de UI con el helper offchain
Obtenga la mint account y el sysvar del reloj, luego calcule la cantidad de UI sin enviar una transacción.
Orden de instrucciones
InterestBearingMintInstruction::Initialize debe ir antes de
InitializeMint. CreateAccount,
InterestBearingMintInstruction::Initialize y InitializeMint deben
incluirse en la misma transacción.
Referencia de código fuente
| Elemento | Descripción | Fuente |
|---|---|---|
InterestBearingConfig | Extensión de mint que almacena la autoridad de tasa de interés, marcas de tiempo y tasas actuales e históricas. | Fuente |
InterestBearingMintInstruction::Initialize | Instrucción que inicializa la configuración de interés antes de InitializeMint. | Fuente |
InterestBearingMintInstruction::UpdateRate | Instrucción que cambia la tasa de interés actual del mint. | Fuente |
AmountToUiAmount | Instrucción que devuelve la cadena de cantidad de UI actual para una cantidad de tokens usando la configuración activa del mint. | Fuente |
InterestBearingConfig::amount_to_ui_amount | Helper que convierte una cantidad de tokens en una cantidad de UI con interés para una marca de tiempo. | Fuente |
process_initialize | Lógica del procesador que inicializa InterestBearingConfig y registra las marcas de tiempo y tasa iniciales. | Fuente |
process_update_rate | Lógica del procesador que actualiza la tasa actual, recalcula la tasa promedio ponderada por tiempo y registra la marca de tiempo de actualización. | Fuente |
process_amount_to_ui_amount | Lógica del procesador que devuelve la cadena de cantidad de UI usando la configuración de interés activa del mint. | Fuente |
Typescript
El ejemplo Kit a continuación utiliza las instrucciones generadas
directamente. Se incluyen ejemplos heredados que usan @solana/web3.js e
@solana/spl-token como referencia.
Kit
import {lamports,createClient,appendTransactionMessageInstructions,createTransactionMessage,generateKeyPairSigner,getBase64EncodedWireTransaction,pipe,setTransactionMessageFeePayerSigner,setTransactionMessageLifetimeUsingBlockhash,signTransactionMessageWithSigners,unwrapOption} from "@solana/kit";import { solanaRpc, rpcAirdrop } from "@solana/kit-plugin-rpc";import { generatedPayer, airdropPayer } from "@solana/kit-plugin-signer";import { getCreateAccountInstruction } from "@solana-program/system";import {amountToUiAmountForMintWithoutSimulation,extension,fetchMint,findAssociatedTokenPda,getAmountToUiAmountInstruction,getCreateAssociatedTokenInstructionAsync,getInitializeInterestBearingMintInstruction,getInitializeMintInstruction,getMintSize,getMintToCheckedInstruction,getUpdateRateInterestBearingMintInstruction,isExtension,TOKEN_2022_PROGRAM_ADDRESS} from "@solana-program/token-2022";const client = await createClient().use(generatedPayer()).use(solanaRpc({rpcUrl: "http://localhost:8899",rpcSubscriptionsUrl: "ws://localhost:8900"})).use(rpcAirdrop()).use(airdropPayer(lamports(1_000_000_000n)));const mint = await generateKeyPairSigner();const recipient = await generateKeyPairSigner();const tokenAmount = 1_000_000_000_000n;const interestBearingExtension = extension("InterestBearingConfig", {rateAuthority: client.payer.address,initializationTimestamp: BigInt(Math.floor(Date.now() / 1000)),lastUpdateTimestamp: BigInt(Math.floor(Date.now() / 1000)),preUpdateAverageRate: 30000,currentRate: 30000});const mintSpace = BigInt(getMintSize([interestBearingExtension]));const mintRent = await client.rpc.getMinimumBalanceForRentExemption(mintSpace).send();const [tokenAccount] = await findAssociatedTokenPda({mint: mint.address,owner: recipient.address,tokenProgram: TOKEN_2022_PROGRAM_ADDRESS});await client.sendTransaction([getCreateAccountInstruction({payer: client.payer, // Account funding the new mint account.newAccount: mint, // New mint account to create.lamports: mintRent, // Lamports funding the mint account rent.space: mintSpace, // Account size in bytes for the mint plus InterestBearingConfig.programAddress: TOKEN_2022_PROGRAM_ADDRESS // Program that owns the mint account.}),getInitializeInterestBearingMintInstruction({mint: mint.address, // Mint account that stores the InterestBearingConfig extension.rateAuthority: client.payer.address, // Authority allowed to update the interest rate later.rate: 30000 // Interest rate in basis points.}),getInitializeMintInstruction({mint: mint.address, // Mint account to initialize.decimals: 0, // Number of decimals for the token.mintAuthority: client.payer.address, // Authority allowed to mint new tokens.freezeAuthority: client.payer.address // Authority allowed to freeze token accounts.})]);await client.sendTransaction([await getCreateAssociatedTokenInstructionAsync({payer: client.payer, // Account funding the associated token account creation.mint: mint.address, // Mint for the associated token account.owner: recipient.address // Owner of the token account.}),getMintToCheckedInstruction({mint: mint.address, // Mint account that issues the tokens.token: tokenAccount, // Token account receiving the newly minted tokens.mintAuthority: client.payer, // Signer authorized to mint new tokens.amount: tokenAmount, // Token amount in base units.decimals: 0 // Decimals defined on the mint.})]);await new Promise((resolve) => setTimeout(resolve, 2_000));const calculatedUiAmount = await amountToUiAmountForMintWithoutSimulation(client.rpc,mint.address,tokenAmount);const amountToUiInstruction = getAmountToUiAmountInstruction({mint: mint.address, // Mint whose UI amount conversion is being simulated.amount: tokenAmount // Token amount in base units.});const { value: latestBlockhash } = await client.rpc.getLatestBlockhash().send();const amountToUiMessage = pipe(createTransactionMessage({ version: 0 }),(tx) => setTransactionMessageFeePayerSigner(client.payer, tx),(tx) => setTransactionMessageLifetimeUsingBlockhash(latestBlockhash, tx),(tx) => appendTransactionMessageInstructions([amountToUiInstruction], tx));const signedAmountToUiMessage =await signTransactionMessageWithSigners(amountToUiMessage);const simulation = await client.rpc.simulateTransaction(getBase64EncodedWireTransaction(signedAmountToUiMessage),{encoding: "base64"}).send();const simulatedUiAmount = Buffer.from(simulation.value.returnData?.data?.[0] ?? "","base64").toString("utf8");const updateRateInstruction = getUpdateRateInterestBearingMintInstruction({mint: mint.address, // Mint account that stores the InterestBearingConfig extension.rateAuthority: client.payer, // Signer authorized to update the interest rate.rate: 15000 // New interest rate in basis points.});await client.sendTransaction([updateRateInstruction]);const mintAccount = await fetchMint(client.rpc, mint.address);const interestBearingConfig = (unwrapOption(mintAccount.data.extensions) ?? []).find((item) => isExtension("InterestBearingConfig", item));console.log("Mint Address:", mint.address);console.log("Token Account:", tokenAccount);console.log("Calculated UI Amount:", calculatedUiAmount);console.log("Simulated UI Amount:", simulatedUiAmount);console.log("InterestBearingConfig:", interestBearingConfig);
Web3.js
import {Connection,Keypair,sendAndConfirmTransaction,SystemProgram,Transaction,LAMPORTS_PER_SOL} from "@solana/web3.js";import {ASSOCIATED_TOKEN_PROGRAM_ID,amountToUiAmountForMintWithoutSimulation,createAmountToUiAmountInstruction,createAssociatedTokenAccountInstruction,createInitializeMintInstruction,createInitializeInterestBearingMintInstruction,createMintToCheckedInstruction,createUpdateRateInterestBearingMintInstruction,ExtensionType,getAssociatedTokenAddressSync,getInterestBearingMintConfigState,getMint,getMintLen,TOKEN_2022_PROGRAM_ID} from "@solana/spl-token";const connection = new Connection("http://localhost:8899", "confirmed");const latestBlockhash = await connection.getLatestBlockhash();const feePayer = Keypair.generate();const recipient = Keypair.generate();const tokenAmount = 1_000_000_000_000n;const airdropSignature = await connection.requestAirdrop(feePayer.publicKey,5 * LAMPORTS_PER_SOL);await connection.confirmTransaction({blockhash: latestBlockhash.blockhash,lastValidBlockHeight: latestBlockhash.lastValidBlockHeight,signature: airdropSignature});const extensions = [ExtensionType.InterestBearingConfig];const mint = Keypair.generate();const mintLength = getMintLen(extensions);const mintRent = await connection.getMinimumBalanceForRentExemption(mintLength);const tokenAccount = getAssociatedTokenAddressSync(mint.publicKey,recipient.publicKey,false,TOKEN_2022_PROGRAM_ID,ASSOCIATED_TOKEN_PROGRAM_ID);const createMintAccountInstruction = SystemProgram.createAccount({fromPubkey: feePayer.publicKey, // Account funding the new mint account.newAccountPubkey: mint.publicKey, // New mint account to create.space: mintLength, // Account size in bytes for the mint plus InterestBearingConfig.lamports: mintRent, // Lamports funding the mint account rent.programId: TOKEN_2022_PROGRAM_ID // Program that owns the mint account.});const initializeInterestBearingInstruction =createInitializeInterestBearingMintInstruction(mint.publicKey, // Mint account that stores the InterestBearingConfig extension.feePayer.publicKey, // Authority allowed to update the interest rate later.30000, // Interest rate in basis points.TOKEN_2022_PROGRAM_ID // Token program that owns the mint.);const initializeMintInstruction = createInitializeMintInstruction(mint.publicKey, // Mint account to initialize.0, // Number of decimals for the token.feePayer.publicKey, // Authority allowed to mint new tokens.feePayer.publicKey, // Authority allowed to freeze token accounts.TOKEN_2022_PROGRAM_ID // Program that owns the mint account.);const createTokenAccountInstruction = createAssociatedTokenAccountInstruction(feePayer.publicKey, // Account funding the associated token account creation.tokenAccount, // Associated token account address to create.recipient.publicKey, // Owner of the token account.mint.publicKey, // Mint for the associated token account.TOKEN_2022_PROGRAM_ID, // Token program that owns the token account.ASSOCIATED_TOKEN_PROGRAM_ID // Associated Token Program that creates the account.);const mintToTokenAccountInstruction = createMintToCheckedInstruction(mint.publicKey, // Mint account that issues the tokens.tokenAccount, // Token account receiving the newly minted tokens.feePayer.publicKey, // Signer authorized to mint new tokens.tokenAmount, // Token amount in base units.0, // Decimals defined on the mint.[], // Additional multisig signers.TOKEN_2022_PROGRAM_ID // Token program that owns the mint and token account.);await sendAndConfirmTransaction(connection,new Transaction({feePayer: feePayer.publicKey,blockhash: latestBlockhash.blockhash,lastValidBlockHeight: latestBlockhash.lastValidBlockHeight}).add(createMintAccountInstruction,initializeInterestBearingInstruction,initializeMintInstruction),[feePayer, mint]);await sendAndConfirmTransaction(connection,new Transaction().add(createTokenAccountInstruction,mintToTokenAccountInstruction),[feePayer]);await new Promise((resolve) => setTimeout(resolve, 2_000));const calculatedUiAmount = await amountToUiAmountForMintWithoutSimulation(connection,mint.publicKey,tokenAmount);const amountToUiInstruction = createAmountToUiAmountInstruction(mint.publicKey, // Mint whose UI amount conversion is being simulated.tokenAmount, // Token amount in base units.TOKEN_2022_PROGRAM_ID // Token program that owns the mint.);const amountToUiSimulation = await connection.simulateTransaction(new Transaction().add(amountToUiInstruction),[feePayer],false);const simulatedUiAmount = Buffer.from(amountToUiSimulation.value.returnData?.data?.[0] ?? "","base64").toString("utf8");const updateRateInstruction = createUpdateRateInterestBearingMintInstruction(mint.publicKey, // Mint account that stores the InterestBearingConfig extension.feePayer.publicKey, // Signer authorized to update the interest rate.15000, // New interest rate in basis points.[], // Additional multisig signers.TOKEN_2022_PROGRAM_ID // Token program that owns the mint.);await sendAndConfirmTransaction(connection,new Transaction().add(updateRateInstruction),[feePayer]);const mintAccount = await getMint(connection,mint.publicKey,"confirmed",TOKEN_2022_PROGRAM_ID);const interestBearingConfig = getInterestBearingMintConfigState(mintAccount);console.log("Mint Address:", mint.publicKey.toBase58());console.log("Token Account:", tokenAccount.toBase58());console.log("Calculated UI Amount:", calculatedUiAmount);console.log("Simulated UI Amount:", simulatedUiAmount);console.log("InterestBearingConfig:", interestBearingConfig);
Rust
use anyhow::{anyhow, Result};use base64::prelude::{Engine as _, BASE64_STANDARD};use solana_client::nonblocking::rpc_client::RpcClient;use solana_commitment_config::CommitmentConfig;use solana_sdk::{sysvar::clock::{self, Clock},signature::{Keypair, Signer},transaction::Transaction,};use solana_system_interface::instruction::create_account;use spl_associated_token_account_interface::{address::get_associated_token_address_with_program_id,instruction::create_associated_token_account,};use spl_token_2022_interface::{extension::{interest_bearing_mint::{instruction::{initialize as initialize_interest_bearing_instruction, update_rate,},InterestBearingConfig,},BaseStateWithExtensions, ExtensionType, StateWithExtensions,},instruction::{amount_to_ui_amount, initialize_mint, mint_to_checked},state::Mint,ID as TOKEN_2022_PROGRAM_ID,};#[tokio::main]async fn main() -> Result<()> {let client = RpcClient::new_with_commitment(String::from("http://localhost:8899"),CommitmentConfig::confirmed(),);let fee_payer = Keypair::new();let recipient = Keypair::new();let token_amount = 1_000_000_000_000u64;let airdrop_signature = client.request_airdrop(&fee_payer.pubkey(), 5_000_000_000).await?;loop {let confirmed = client.confirm_transaction(&airdrop_signature).await?;if confirmed {break;}}let mint = Keypair::new();let mint_space =ExtensionType::try_calculate_account_len::<Mint>(&[ExtensionType::InterestBearingConfig])?;let mint_rent = client.get_minimum_balance_for_rent_exemption(mint_space).await?;let create_mint_account_instruction = create_account(&fee_payer.pubkey(), // Account funding the new mint account.&mint.pubkey(), // New mint account to create.mint_rent, // Lamports funding the mint account rent.mint_space as u64, // Account size in bytes for the mint plus InterestBearingConfig.&TOKEN_2022_PROGRAM_ID, // Program that owns the mint account.);let initialize_interest_bearing_instruction = initialize_interest_bearing_instruction(&TOKEN_2022_PROGRAM_ID, // Token program that owns the mint.&mint.pubkey(), // Mint account that stores the InterestBearingConfig extension.Some(fee_payer.pubkey()), // Authority allowed to update the interest rate later.30000, // Interest rate in basis points.)?;let initialize_mint_instruction = initialize_mint(&TOKEN_2022_PROGRAM_ID, // Program that owns the mint account.&mint.pubkey(), // Mint account to initialize.&fee_payer.pubkey(), // Authority allowed to mint new tokens.Some(&fee_payer.pubkey()), // Authority allowed to freeze token accounts.0, // Number of decimals for the token.)?;let create_mint_transaction = Transaction::new_signed_with_payer(&[create_mint_account_instruction,initialize_interest_bearing_instruction,initialize_mint_instruction,],Some(&fee_payer.pubkey()),&[&fee_payer, &mint],client.get_latest_blockhash().await?,);client.send_and_confirm_transaction(&create_mint_transaction).await?;let token_account = get_associated_token_address_with_program_id(&recipient.pubkey(),&mint.pubkey(),&TOKEN_2022_PROGRAM_ID,);let create_token_account_instruction = create_associated_token_account(&fee_payer.pubkey(), // Account funding the associated token account creation.&recipient.pubkey(), // Owner of the token account.&mint.pubkey(), // Mint for the associated token account.&TOKEN_2022_PROGRAM_ID, // Token program that owns the token account.);let mint_to_token_account_instruction = mint_to_checked(&TOKEN_2022_PROGRAM_ID, // Token program that owns the mint and token account.&mint.pubkey(), // Mint account that issues the tokens.&token_account, // Token account receiving the newly minted tokens.&fee_payer.pubkey(), // Signer authorized to mint new tokens.&[], // Additional multisig signers.token_amount, // Token amount in base units.0, // Decimals defined on the mint.)?;let create_token_account_transaction = Transaction::new_signed_with_payer(&[create_token_account_instruction,mint_to_token_account_instruction,],Some(&fee_payer.pubkey()),&[&fee_payer],client.get_latest_blockhash().await?,);client.send_and_confirm_transaction(&create_token_account_transaction).await?;tokio::time::sleep(std::time::Duration::from_secs(2)).await;let mint_account = client.get_account(&mint.pubkey()).await?;let mint_state = StateWithExtensions::<Mint>::unpack(&mint_account.data)?;let interest_bearing_config = mint_state.get_extension::<InterestBearingConfig>()?;let clock_account = client.get_account(&clock::ID).await?;let clock: Clock = clock_account.deserialize_data()?;let calculated_ui_amount = interest_bearing_config.amount_to_ui_amount(token_amount, mint_state.base.decimals, clock.unix_timestamp).ok_or_else(|| anyhow!("Failed to calculate UI amount"))?;let amount_to_ui_instruction = amount_to_ui_amount(&TOKEN_2022_PROGRAM_ID, // Token program that owns the mint.&mint.pubkey(), // Mint whose UI amount conversion is being simulated.token_amount, // Token amount in base units.)?;let amount_to_ui_blockhash = client.get_latest_blockhash().await?;let amount_to_ui_transaction = Transaction::new_signed_with_payer(&[amount_to_ui_instruction],Some(&fee_payer.pubkey()),&[&fee_payer],amount_to_ui_blockhash,);let amount_to_ui_result = client.simulate_transaction(&amount_to_ui_transaction).await?;let simulated_ui_amount = String::from_utf8(BASE64_STANDARD.decode(amount_to_ui_result.value.return_data.ok_or_else(|| anyhow!("Expected AmountToUiAmount return data"))?.data.0,)?,)?;let update_rate_instruction = update_rate(&TOKEN_2022_PROGRAM_ID, // Token program that owns the mint.&mint.pubkey(), // Mint account that stores the InterestBearingConfig extension.&fee_payer.pubkey(), // Signer authorized to update the interest rate.&[], // Additional multisig signers.15000, // New interest rate in basis points.)?;let update_rate_transaction = Transaction::new_signed_with_payer(&[update_rate_instruction],Some(&fee_payer.pubkey()),&[&fee_payer],client.get_latest_blockhash().await?,);client.send_and_confirm_transaction(&update_rate_transaction).await?;let updated_mint_account = client.get_account(&mint.pubkey()).await?;let updated_mint_state = StateWithExtensions::<Mint>::unpack(&updated_mint_account.data)?;let interest_bearing_config = updated_mint_state.get_extension::<InterestBearingConfig>()?;println!("Mint Address: {}", mint.pubkey());println!("Token Account: {}", token_account);println!("Calculated UI Amount: {}", calculated_ui_amount);println!("Simulated UI Amount: {}", simulated_ui_amount);println!("InterestBearingConfig: {:#?}", interest_bearing_config);Ok(())}
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