---
title: Making an x402 Payment
seoTitle: Make a Sandbox x402 Payment on Solana
description:
  Launch an agent with Pay and complete one x402 V2 payment against a local
  sandbox API without moving real funds.
---

Use [Pay](https://pay.sh) to run an x402 V2 API and give Claude Code a
payment-aware HTTP client. The API, payer wallet, and settlement all use the
Solana sandbox, so this walkthrough does not require an account or real funds.

You need a terminal, Pay, and Claude Code installed.

## 1. Install Pay

On macOS, install the prebuilt binary:

```bash
brew install pay
pay --version
```

On other platforms, install the npm package:

```bash
npm install --global @solana/pay
pay --version
```

## 2. Start an x402 sandbox API

Create `x402-demo.yaml`:

```yaml filename=x402-demo.yaml
name: x402-demo
subdomain: x402-demo
title: "x402 Demo"
description: "Minimal x402 V2 sandbox endpoint."
category: devtools
version: v1
routing:
  type: respond
operator:
  currencies:
    usd: ["USDC"]
  network: "localnet"
  fee_payer: true
endpoints:
  - method: GET
    path: "report"
    description: "Return a sandbox report."
    metering:
      schemes: [x402-exact]
      dimensions:
        - direction: usage
          unit: requests
          scale: 1
          tiers:
            - price_usd: 0.001
```

Start the API and leave it running:

```bash
pay --sandbox server start x402-demo.yaml --bind 127.0.0.1:1402
```

The `x402-exact` scheme makes this an x402-only endpoint. Sandbox mode creates
and funds temporary operator and payer accounts automatically.

## 3. Launch the agent with Pay

In another terminal, start Claude Code in sandbox mode:

```bash
pay --sandbox claude
```

Pay attaches its local MCP tools to the agent session. The agent does not
receive a private key.

## 4. Make one x402 request

Paste this prompt into the agent:

```text
Use Pay to make exactly one sandbox x402 API request to
http://127.0.0.1:1402/report.

Before paying, show me the amount and ask for approval. Then return the API
result and payment receipt. Do not make any other paid requests.
```

The request follows one complete x402 V2 payment loop:

1. The API returns `402 Payment Required` with a `PAYMENT-REQUIRED` challenge.
2. Pay validates the x402 requirements and displays the payment terms.
3. After approval, the sandbox wallet signs and Pay retries the request with
   `PAYMENT-SIGNATURE`.
4. The API returns the result with a `PAYMENT-RESPONSE` receipt.

No real funds move. Rejecting the approval stops the request.

Continue with [x402 on Solana](/docs/payments/agentic-payments/x402) to build an
x402 V2 client and resource server, or
[become an x402 facilitator](/docs/tools/x402-facilitator).