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Transaction (TX) priority is achieved by paying a Prioritization Fee in additionto the Base Fee. By default the compute budget is the product of 200,000 ComputeUnits (CU) * number of instructions, with a max of 1.4M CU. The Base Fee is5,000 Lamports per signature. A microLamport is 0.000001 Lamports.
Info
You can find a detailed guide here onhow to use priority fees.
The total compute budget or Prioritization Fee for a single TX can be changed byadding instructions from the ComputeBudgetProgram.
ComputeBudgetProgram.setComputeUnitPrice({ microLamports: number }) will add aPrioritization Fee above the Base Fee (5,000 Lamports). The value provided inmicroLamports will be multiplied by the CU budget to determine thePrioritization Fee in Lamports. For example, if your CU budget is 1M CU, and youadd 1 microLamport/CU, the Prioritization Fee will be 1 Lamport (1M *0.000001). The total fee will then be 5001 Lamports.
Use ComputeBudgetProgram.setComputeUnitLimit({ units: number }) to set the newcompute budget. The value provided will replace the default value. Transactionsshould request the minimum amount of CU required for execution to maximizethroughput, or minimize fees.
add-priority-fees.ts
import { BN } from "@coral-xyz/anchor";import { Keypair, Connection, LAMPORTS_PER_SOL, sendAndConfirmTransaction, ComputeBudgetProgram, SystemProgram, Transaction,} from "@solana/web3.js"; (async () => { const payer = Keypair.generate(); const toAccount = Keypair.generate().publicKey; const connection = new Connection("http://127.0.0.1:8899", "confirmed"); const airdropSignature = await connection.requestAirdrop( payer.publicKey, LAMPORTS_PER_SOL, ); await connection.confirmTransaction(airdropSignature); // request a specific compute unit budget const modifyComputeUnits = ComputeBudgetProgram.setComputeUnitLimit({ units: 1000000, }); // set the desired priority fee const addPriorityFee = ComputeBudgetProgram.setComputeUnitPrice({ microLamports: 1, }); // Total fee will be 5,001 Lamports for 1M CU const transaction = new Transaction() .add(modifyComputeUnits) .add(addPriorityFee) .add( SystemProgram.transfer({ fromPubkey: payer.publicKey, toPubkey: toAccount, lamports: 10000000, }), ); const signature = await sendAndConfirmTransaction(connection, transaction, [ payer, ]); console.log(signature); const result = await connection.getParsedTransaction(signature); console.log(result);})();