fund pkp when minting

routes/auth/mintAndFetch.ts

@@ -1,13 +1,21 @@
 import { Request } from "express";
 import { Response } from "express-serve-static-core";
 import { ParsedQs } from "qs";
-import { getPKPsForAuthMethod, mintPKP } from "../../lit";
+import {
+	getPkpEthAddress,
+	getPKPsForAuthMethod,
+	getSigner,
+	mintPKP,
+} from "../../lit";
 import {
 	AuthMethodVerifyToFetchResponse,
 	FetchRequest,
 	MintNextAndAddAuthMethodsRequest,
 	MintNextAndAddAuthMethodsResponse,
 } from "../../models";
+import { ethers } from "ethers";
+import { getPKPEthAddressFromPKPMintedEvent } from "../../utils/receipt";
+import { Sequencer } from "../../lib/sequencer";
 
 export async function mintNextAndAddAuthMethodsHandler(
 	req: Request<
@@ -29,6 +37,38 @@ export async function mintNextAndAddAuthMethodsHandler(
 		console.info("Minted PKP", {
 			requestId: mintTx.hash,
 		});
+		const signer = getSigner();
+		const receipt = await signer.provider.waitForTransaction(mintTx.hash!);
+		const pkpEthAddress = await getPKPEthAddressFromPKPMintedEvent(receipt);
+
+		// send 0.001 eth to the pkp to fund it.
+		// we will replace this with EIP2771 funding once we have that working
+		const sequencer = Sequencer.Instance;
+		Sequencer.Wallet = signer;
+		const gasToFund = ethers.utils.parseEther("0.001");
+
+		const gasFundingTxn = await sequencer.wait({
+			action: (...args) => {
+				const paramsToFn = Object.assign(
+					{},
+					...args,
+				) as ethers.providers.TransactionRequest;
+				return signer.sendTransaction(paramsToFn);
+			},
+			params: [{ to: pkpEthAddress, value: gasToFund }],
+			transactionData: {},
+		});
+		console.log("gasFundingTxn", gasFundingTxn);
+		// wait for confirmation
+		await gasFundingTxn.wait();
+
+		// const tx = await (
+		// 	await getSigner()
+		// ).sendTransaction({
+		// 	to: mintTx.to,
+		// 	value: ethers.utils.parseEther("0.001"),
+		// });
+		// await tx.wait();
 		return res.status(200).json({
 			requestId: mintTx.hash,
 		});

tests/routes/auth/mintAndFetch.test.ts

@@ -169,5 +169,16 @@ describe("mintNextAndAddAuthMethods Integration Tests", () => {
 		// Verify that the random address owns the NFT
 		const owner = await pkpNft.ownerOf(tokenId);
 		expect(owner.toLowerCase()).toBe(sendToAddress.toLowerCase());
+
+		// get PKP eth address from the PKP NFT contract
+		const pkpEthAddress = await pkpNft.getEthAddress(tokenId);
+		expect(pkpEthAddress).toBeDefined();
+
+		// check that the pkp has 0.001 eth
+		const pkpBalance = await provider.getBalance(pkpEthAddress);
+		console.log("pkpBalance", pkpBalance);
+		expect(pkpBalance.toHexString()).toBe(
+			ethers.utils.parseEther("0.001").toHexString(),
+		);
 	}, 30000); // Increase timeout to 30s since we're waiting for real transactions
 });

utils/receipt.ts

@@ -1,4 +1,6 @@
-import { providers } from "ethers";
+import config from "../config";
+import { ethers, providers } from "ethers";
+import { getPkpNftContract } from "../lit";
 
 const TRANSFER_EVENT_SIGNATURE =
 	"0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef";
@@ -24,3 +26,22 @@ export async function getTokenIdFromTransferEvent(
 
 	return transferEventLog.topics[3];
 }
+
+export async function getPKPEthAddressFromPKPMintedEvent(
+	receipt: providers.TransactionReceipt,
+): Promise<string> {
+	const pkpNft = getPkpNftContract(config.network);
+	const mintEvent = receipt.logs.find((log) => {
+		try {
+			return pkpNft.interface.parseLog(log).name === "PKPMinted";
+		} catch {
+			return false;
+		}
+	});
+	if (!mintEvent) {
+		throw new Error("No PKPMinted event found in receipt");
+	}
+	const pkpPubkey = pkpNft.interface.parseLog(mintEvent).args.pubkey;
+
+	return ethers.utils.computeAddress(pkpPubkey);
+}