---
title: "Make your first paid request with x402"
description: "Send a request to x402.erpc.global, read the price in the 402 response, pay it with an x402 client and get the RPC result with a settlement receipt."
canonical: "https://erpc.global/en/doc/x402/quickstart/"
locale: "en"
---

# Make your first paid request with x402

This guide takes one Solana request through x402: read the price, pay it, and get the answer with a settlement receipt. The other 15 chains work the same way at their own routes.

You need a wallet that holds USDC on Solana, or USDC or EURC on Base, and an x402 client: the software that reads the 402 response, signs a payment from your wallet and sends the request again with it. For x402 clients, see the x402 documentation at [x402.org](https://x402.org/).

## 1. Send the request

Send the RPC request without a payment:

```bash
curl -i https://x402.erpc.global/v1/solana-mainnet \
  --header 'Content-Type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"getSlot"}'
```

The answer is 402 Payment Required. Its headers give the method and the price:

```http
HTTP/2 402
x-payment-required: eyJ4NDAyVmVyc2lvbiI6Mi…
x-rpc-methods: getSlot
x-rpc-weight: 1000
x-rpc-price-usd: 0.001
```

The body lists the payment options in `accepts`, one for each stablecoin the request can be paid with. `amount` is in the stablecoin's smallest unit, so 1000 is 0.001 USDC, or 0.001 EURC:

```json
{
  "error": { "code": "payment_required", "message": "Payment required", "request_id": "…" },
  "x402Version": 2,
  "accepts": [
    { "scheme": "exact", "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp", "amount": "1000", "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v", … },
    { "scheme": "exact", "network": "eip155:8453", "amount": "1000", "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", … },
    { "scheme": "exact", "network": "eip155:8453", "amount": "1000", "asset": "0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42", … }
  ],
  "pricing": { "methods": ["getSlot"], …, "weight": 1000, "rawWeight": 42, …, "price": "$0.001", … },
  …
}
```

## 2. Pay with an x402 client

Give the 402 response to your x402 client. It picks an option your wallet can pay, signs a payment for that amount and encodes it for the X-Payment header. The payment needs no SOL or ETH for network fees.

## 3. Send the request again with the payment

Send the same body again, with the payment in the X-Payment header:

```bash
curl -i https://x402.erpc.global/v1/solana-mainnet \
  --header 'Content-Type: application/json' \
  --header 'X-Payment: <PAYMENT_PAYLOAD>' \
  --data '{"jsonrpc":"2.0","id":1,"method":"getSlot"}'
```

Keep the body unchanged. The price is worked out from the body, so if a changed body has a different price, the payment no longer matches it and is answered with `price_mismatch`.

Once the payment is verified and settled, the RPC answer comes back with the settlement receipt in the X-Payment-Response header:

```http
HTTP/2 200
x-payment-response: <RECEIPT>
```

```json
{ "jsonrpc": "2.0", "id": 1, "result": … }
```

A payment pays for one request. If you send the same payment again, it is refused with 402 `payment_invalid` or 409 `duplicate_payment`, and the request is not forwarded again.

## Responses

A request that x402.erpc.global answers with an error before it asks for payment costs nothing.

| Status | `error.code` | What happened |
| --- | --- | --- |
| 402 | `payment_required` | No payment was sent. The body gives the price and the payment options. |
| 402 | `payment_invalid` | The payment did not pass verification. Sign a new payment and send the request again. |
| 402 | `price_mismatch` | The payment does not match an option this request's 402 offered, such as its price. |
| 402 | `payment_amount_too_low` | The amount is below the smallest payment x402.erpc.global settles. |
| 402 | `settlement_failed` | The settlement was reported as failed. The response offers the payment options again. |
| 409 | `duplicate_payment` | The payment was already used. |
| 400 | `method_not_supported`, `invalid_request` | The route does not sell the method, or does not take the body. Nothing is charged. |
| 413 | `batch_too_large` | The batch has more than 100 calls. Nothing is charged. |
| 500 | `configuration_error` | The route cannot serve requests right now. Nothing is charged. |
| 503 | `payment_unavailable` | No payment option can be offered right now. Nothing is charged. Try again after the Retry-After seconds. |
| 503 | `service_busy` | Too many requests at once. Nothing is charged. Try again after the Retry-After seconds. |
| 502 | `settlement_failed` | The settlement result is unknown: the payment may have gone through, and no receipt is attached. Check on Solana or Base whether the payment you signed went through before you sign a new one. |
| 502, 504 | `upstream_error`, `upstream_timeout` | The payment settled, but the chain did not answer, or did not answer in time. The receipt is still attached. Sending the request again takes a new payment. |

On Solana, a call that would read too much, such as an unfiltered `getProgramAccounts` on a large program, is answered with HTTP 200 and a JSON-RPC error before any payment is asked for, so it costs nothing.

## Next steps

- [How x402 prices a request](https://erpc.global/en/doc/x402/pricing/): the price of one call, the \$0.001 minimum and batches.
- [x402 overview](https://erpc.global/en/doc/x402/overview/): every chain's route and the payment options.
- [OpenAPI document](https://x402.erpc.global/doc): the request and response shape of every route.