solana-agent-kit/src/tools/lend.ts

import { VersionedTransaction } from "@solana/web3.js";
import { SolanaAgentKit } from "../index";

/**
 * Lend tokens for yields using Lulo
 * @param agent SolanaAgentKit instance
 * @param amount Amount of USDC to lend
 * @returns Transaction signature
 */
export async function lendAsset(
  agent: SolanaAgentKit,
  amount: number,
): Promise<string> {
  try {
    const response = await fetch(
      `https://blink.lulo.fi/actions?amount=${amount}&symbol=USDC`,
      {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          account: agent.wallet.publicKey.toBase58(),
        }),
      },
    );

    const data = await response.json();

    // Deserialize the transaction
    const luloTxn = VersionedTransaction.deserialize(
      Buffer.from(data.transaction, "base64"),
    );

    // Get a recent blockhash and set it
    const { blockhash } = await agent.connection.getLatestBlockhash();
    luloTxn.message.recentBlockhash = blockhash;

    // Sign and send transaction
    luloTxn.sign([agent.wallet]);

    const signature = await agent.connection.sendTransaction(luloTxn, {
      preflightCommitment: "confirmed",
      maxRetries: 3,
    });

    // Wait for confirmation using the latest strategy
    const latestBlockhash = await agent.connection.getLatestBlockhash();
    await agent.connection.confirmTransaction({
      signature,
      blockhash: latestBlockhash.blockhash,
      lastValidBlockHeight: latestBlockhash.lastValidBlockHeight,
    });

    return signature;
  } catch (error: any) {
    throw new Error(`Lending failed: ${error.message}`);
  }
}