Migrate from Alchemy to GoldRush

// BEFORE -- Alchemy: POST, key in the URL path, networks in the body.
const res = await fetch(
  "https://api.g.alchemy.com/data/v1/" + process.env.ALCHEMY_API_KEY +
    "/assets/tokens/by-address",
  {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      addresses: [{ address, networks: ["eth-mainnet", "base-mainnet"] }],
      withPrices: true,
    }),
  }
);
const body = await res.json();
const tokens = body.data.tokens;

// AFTER -- GoldRush: GET, key in the header, chains as a query param.
const res = await fetch(
  "https://api.covalenthq.com/v1/allchains/address/" + address +
    "/balances/?chains=eth-mainnet,base-mainnet",
  { headers: { Authorization: "Bearer " + process.env.GOLDRUSH_API_KEY } }
);
const { data, error, error_message } = await res.json();
if (error) throw new Error(error_message);
const tokens = data.items; // quote (USD) already on each item

// BEFORE -- Alchemy: getAssetTransfers for the list, then receipts for detail.
const rpc = "https://eth-mainnet.g.alchemy.com/v2/" + process.env.ALCHEMY_API_KEY;

const transfers = await fetch(rpc, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    id: 1,
    jsonrpc: "2.0",
    method: "alchemy_getAssetTransfers",
    params: [{
      fromAddress: address,
      category: ["external", "internal", "erc20", "erc721", "erc1155"],
    }],
  }),
}).then((r) => r.json());

// Second pass for receipts / logs, batched by block.
const receipts = await fetch(rpc, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    id: 1,
    jsonrpc: "2.0",
    method: "alchemy_getTransactionReceipts",
    params: [{ blockNumber: transfers.result.transfers[0].blockNum }],
  }),
}).then((r) => r.json());

// AFTER -- GoldRush: one GET, decoded log_events already attached.
const res = await fetch(
  "https://api.covalenthq.com/v1/eth-mainnet/address/" + address +
    "/transactions_v3/page/0/",
  { headers: { Authorization: "Bearer " + process.env.GOLDRUSH_API_KEY } }
);
const { data, error, error_message } = await res.json();
if (error) throw new Error(error_message);

for (const tx of data.items) {
  // Decoded against the contract ABI -- no second call, no manual decoding.
  for (const ev of tx.log_events ?? []) {
    console.log(ev.decoded?.name, ev.sender_contract_ticker_symbol);
  }
}

# BEFORE -- Alchemy puts the API key in the path. It lands in access logs,
# proxy traces, and anything that records a URL.
curl -X POST \
  "https://api.g.alchemy.com/data/v1/$ALCHEMY_API_KEY/assets/tokens/by-address" \
  -H "Content-Type: application/json" \
  -d '{"addresses":[{"address":"'$ADDRESS'","networks":["eth-mainnet"]}]}'

# AFTER -- GoldRush keeps the credential in the Authorization header,
# so the URL is safe to log, cache, and share in a bug report.
curl "https://api.covalenthq.com/v1/eth-mainnet/address/$ADDRESS/balances_v2/" \
  -H "Authorization: Bearer $GOLDRUSH_API_KEY"