Prover Application CPI Client Guide

Key Components for Proof Loading

1. Proof Preparation and Chunking

// Decode base64-encoded proof into binary format
const proofBuffer = Buffer.from(base64EncodedProof, 'base64');
console.log(`Decoded proof length: ${proofBuffer.length} bytes`);

// Split the proof into manageable chunks
const MAX_CHUNK_SIZE = 800; // Stay under transaction size limits
const chunks: Buffer[] = [];
for (let i = 0; i < proofBuffer.length; i += MAX_CHUNK_SIZE) {
  chunks.push(proofBuffer.slice(i, Math.min(i + MAX_CHUNK_SIZE, proofBuffer.length)));
}
console.log(`Split proof into ${chunks.length} chunks:`);
chunks.forEach((chunk, i) => console.log(`  Chunk ${i+1}: ${chunk.length} bytes`));

2. Cache Account PDA Derivation

// Derive the cache account PDA from the wallet's public key
const [cachePDA] = anchor.web3.PublicKey.findProgramAddressSync(
  [wallet.publicKey.toBuffer()],
  POLYMER_PROVER_ID
);
console.log(`Using cache PDA: ${cachePDA.toString()}`);

Common Errors	Description	Resolution
Transaction too large	Chunk size exceeds limit	Reduce chunk size (max 800 bytes recommended)
Block height exceeded	Sequence issue	Add delays between transactions
Account ownership error	Wrong PDA derivation	Check PDA seed and POLYMER_PROVER_ID
Out of memory	Proof too large	Ensure uniform chunking across the entire proof

Key Components for Validation

1. Account Preparation with Internal Account

// Derive the cache account PDA - same derivation used in load-proof
const [cachePDA] = anchor.web3.PublicKey.findProgramAddressSync(
  [wallet.publicKey.toBuffer()],
  POLYMER_PROVER_ID
);

// Derive the internal account PDA
const [internalPDA] = anchor.web3.PublicKey.findProgramAddressSync(
  [Buffer.from("internal")],
  POLYMER_PROVER_ID
);

2. Compute Budget Allocation

// CRITICAL: Set higher compute budget limits for validation
const modifyComputeUnits = anchor.web3.ComputeBudgetProgram.setComputeUnitLimit({
  units: 1_400_000 // Proof validation is very compute intensive
});

// Add priority fee to improve transaction confirmation speed
const addPriorityFee = anchor.web3.ComputeBudgetProgram.setComputeUnitPrice({
  microLamports: 10_000
});

Common Errors	Description	Resolution
Exceeded compute units	Not enough compute budget	Set compute unit limit to 1.4M (Solana's per-transaction maximum)
Account not initialized	Cache account doesn't exist	Call load_proof first to create it
AccountDiscriminatorMismatch	Wrong account structure	Use correct PDA derivation
Missing return data	CPI call failed	Ensure all accounts are passed correctly

PDA Reference

Cache Account PDA

The Polymer Prover automatically creates a Cache Account PDA when you call load_proof if it doesn't already exist. This is a key feature to understand:

• PDA Derivation: [authority.key().as_ref()] with Polymer Prover as the owner
• Authority: Typically the user/wallet who initiated the transaction
• Automatic Creation: No need to create this PDA yourself - the Polymer Prover handles this

Internal Account PDA

• PDA Derivation: [b"internal"] with Polymer Prover as the owner
• Already Initialized: This account is already initialized on devnet/mainnet
• Global Account: Shared across all users of the Polymer Prover