Subscribe from an external wallet

export async function getShareholderProof(vaultId, walletAddress) {
  const response = await fetch(
    `${process.env.GROUND_API}/v2/microvaults/vaults/${vaultId}/shareholders/${walletAddress}/proof`,
    { headers: { Authorization: `Bearer ${process.env.GROUND_API_KEY}` } },
  );
  if (!response.ok) throw new Error(await response.text());
  return (await response.json()).proof;
}

const erc20Abi = [
  {
    type: "function", name: "approve", stateMutability: "nonpayable",
    inputs: [{ name: "spender", type: "address" }, { name: "amount", type: "uint256" }],
    outputs: [{ type: "bool" }],
  },
] as const;

const microVaultAbi = [
  {
    type: "function", name: "convertToShares", stateMutability: "view",
    inputs: [{ name: "assets", type: "uint256" }], outputs: [{ type: "uint256" }],
  },
  {
    type: "function", name: "depositWithProof", stateMutability: "nonpayable",
    inputs: [
      { name: "assets", type: "uint256" },
      { name: "receiver", type: "address" },
      { name: "minSharesOut", type: "uint256" },
      { name: "callerProof", type: "bytes32[]" },
      { name: "receiverProof", type: "bytes32[]" },
    ],
    outputs: [{ type: "uint256" }],
  },
] as const;

import { parseUnits, type Address, type Hex } from "viem";

const assets = parseUnits("100", 6);
const approvalHash = await walletClient.writeContract({
  address: usdcAddress as Address,
  abi: erc20Abi,
  functionName: "approve",
  args: [vaultAddress as Address, assets],
});
await publicClient.waitForTransactionReceipt({ hash: approvalHash });

const quotedShares = await publicClient.readContract({
  address: vaultAddress as Address,
  abi: microVaultAbi,
  functionName: "convertToShares",
  args: [assets],
});
const minSharesOut = quotedShares * 9950n / 10000n;

const depositHash = await walletClient.writeContract({
  address: vaultAddress as Address,
  abi: microVaultAbi,
  functionName: "depositWithProof",
  args: [
    assets,
    walletAddress as Address,
    minSharesOut,
    proof.proof as Hex[],
    proof.proof as Hex[],
  ],
});
const receipt = await publicClient.waitForTransactionReceipt({ hash: depositHash });
if (receipt.status !== "success") throw new Error("Subscription reverted");