Answer NEAR RPC and API questions with one library.

<script src="https://js.fastnear.com/intents.js"></script>
<script type="module">
  const oneClick = nearIntents.createOneClickClient();

  const quote = await oneClick.quote({
    dry: true,
    swapType: "EXACT_INPUT",
    slippageTolerance: 100,
    originAsset: "nep141:wrap.near",
    destinationAsset:
      "nep141:17208628f84f5d6ad33f0da3bbbeb27ffcb398eac501a31bd6ad2011e36133a1",
    amount: "1000000000000000000000000",
    depositType: "ORIGIN_CHAIN",
    refundTo: "you.near",
    refundType: "ORIGIN_CHAIN",
    recipient: "you.near",
    recipientType: "DESTINATION_CHAIN",
    deadline: new Date(Date.now() + 10 * 60_000).toISOString(),
  });

  console.log(quote.quote.amountOutFormatted, "USDC for 1 wNEAR");
</script>

import { actions, queryGasKeyNonces, sendTx } from "@fastnear/api";

export async function sendWithGasKey({ accountId, gasSigner, receiverId, nonceIndex = 0 }) {
  const result = await sendTx({
    signerId: accountId,
    signer: gasSigner,
    receiverId,
    actions: [actions.functionCall({ methodName: "ping", args: {}, gas: "30 Tgas", deposit: "0" })],
    nonceIndex,
    waitUntil: "FINAL",
    network: "testnet",
  });

  const nonces = await queryGasKeyNonces({
    accountId,
    publicKey: gasSigner.publicKey,
    blockId: "final",
    network: "testnet",
  });
  return { txHash: result.transaction?.hash ?? null, nonces: nonces.result.nonces };
}

// Lanes are independent nonce sequences, so these do not serialize behind each other.
export const sendOnTwoLanes = (params) =>
  Promise.all([0, 1].map((nonceIndex) => sendWithGasKey({ ...params, nonceIndex })));

import { generateSigner } from "@fastnear/ml-dsa-65";
import { actions, queryProtocolVersion, sendTx } from "@fastnear/api";

// 1. Create an in-memory post-quantum signer.
const signer = generateSigner();

// 2. Enroll signer.publicKey with a classical full-access AddKey
//    (this step needs an existing classical signer).

// 3. Require an RPC on protocol v85, then sign + submit.
if ((await queryProtocolVersion({ network: "testnet" })) < 85) {
  throw new Error("RPC does not support ML-DSA-65 yet");
}

await sendTx({
  signerId: "device.testnet",
  signer,
  receiverId: "device.testnet",
  actions: [actions.transfer("1")],
  waitUntil: "FINAL",
  network: "testnet",
});

<script src="https://js.fastnear.com/wallet.js"></script>
<script src="https://js.fastnear.com/x402.js"></script>
<script type="module">
  // Wire these to buttons: connect first, pay second.
  await nearWallet.connect();

  const signer = nearX402.createFastNearWalletSigner({
    wallet: nearWallet,
  });

  const paidFetch = nearX402.createNearPaymentFetch({
    signer,
    network: "near:testnet",
  });

  const response = await paidFetch("https://seller.example.com/paid");
</script>