> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tentaclepay.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart for agents

> Pay for x402-protected resources from your client or agent on Sui.

This guide wires x402 payments into an HTTP client so your agent pays for protected resources automatically. It uses Sui's `fetch` integration.

<Tip>
  Don't want to write code? The [`tpay` wallet](/wallet/overview) gives any agent a drop-in `tpay curl` and an MCP `pay` tool that handle all of this for you. Use the SDK when you're building payments into your own client. Want your coding agent to write that integration? Install the [`sui-x402-integration` skill](/skills).
</Tip>

<Card title="Full example on GitHub" icon="github" href="https://github.com/tentaclepay/apps/tree/main/examples/x402/exact">
  The complete, runnable version of this guide — `examples/x402/exact/client.ts`.
</Card>

## Prerequisites

* A Sui wallet secret key with a stablecoin balance (use testnet to try it for free)
* Node.js 24+ (or any runtime with WebCrypto and `fetch`)
* An x402-protected endpoint to call — see [Quickstart for sellers](/x402/quickstart-for-sellers)

## 1. Install dependencies

<CodeGroup>
  ```bash npm theme={null}
  npm install @tentaclepay/sui-x402 @mysten/sui @x402/core @x402/fetch
  ```

  ```bash pnpm theme={null}
  pnpm add @tentaclepay/sui-x402 @mysten/sui @x402/core @x402/fetch
  ```

  ```bash bun theme={null}
  bun add @tentaclepay/sui-x402 @mysten/sui @x402/core @x402/fetch
  ```
</CodeGroup>

## 2. Build a signer

A `ClientSuiSigner` is the agent's wallet — an address and a function that signs transaction bytes. Build one from a Sui `Ed25519Keypair`:

```ts client.ts theme={null}
import { Ed25519Keypair } from "@mysten/sui/keypairs/ed25519";
import { fromBase64 } from "@mysten/sui/utils";

import type { ClientSuiSigner } from "@tentaclepay/sui-x402";

const keypair = Ed25519Keypair.fromSecretKey(process.env.CLIENT_PRIVATE_KEY!);

const signer: ClientSuiSigner = {
  address: keypair.toSuiAddress() as `0x${string}`,
  signTransaction: async (bytes: string) => {
    const { signature } = await keypair.signTransaction(fromBase64(bytes));
    return signature;
  },
};
```

## 3. Register the Sui scheme and wrap fetch

Register `ExactSuiScheme` for the network you pay on, then wrap `fetch` so payments are handled transparently:

```ts client.ts theme={null}
import { x402Client } from "@x402/core/client";
import { wrapFetchWithPayment } from "@x402/fetch";

import { ExactSuiScheme } from "@tentaclepay/sui-x402/exact/client";

const client = new x402Client();
client.register("sui:testnet", new ExactSuiScheme(signer));

const fetchWithPayment = wrapFetchWithPayment(fetch, client);
```

## 4. Make the request

Call the protected endpoint as you normally would. When the server returns `402`, the wrapped `fetch` signs the payment and retries automatically:

```ts client.ts theme={null}
const response = await fetchWithPayment("http://localhost:3000/weather", {
  method: "GET",
  headers: { "Content-Type": "application/json" },
});

const data = await response.json();
console.log("Response:", data);
```

## 5. Read the payment receipt

The settlement result comes back in the response headers. Use `x402HTTPClient` to read the transaction digest and link to an explorer:

```ts client.ts theme={null}
import { x402HTTPClient } from "@x402/core/client";

if (response.ok) {
  const httpClient = new x402HTTPClient(client);
  const paymentResponse = httpClient.getPaymentSettleResponse((name) =>
    response.headers.get(name)
  );
  console.log(
    "Transaction:",
    `https://testnet.suivision.xyz/txblock/${paymentResponse.transaction}`
  );
}
```

<Note>
  On mainnet, link to `https://suivision.xyz/txblock/<digest>` instead. Register `"sui:mainnet"` on the client to pay on mainnet.
</Note>

## Next steps

<CardGroup cols={2}>
  <Card title="Supported networks" icon="globe" href="/x402/supported-networks">
    Networks and tokens you can pay with.
  </Card>

  <Card title="Pay across chains" icon="route" href="/cross-chain/overview">
    Use the same Sui wallet to pay services on other chains.
  </Card>
</CardGroup>