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

# Getting started

# Getting Started with X402 Echo Merchant

Use the Echo Merchant to validate your <a href="/v1/x402/clients">x402 client</a> in minutes—no server to deploy.

<Card title="Echo Merchant Website" icon="link" href="https://x402.payai.network">
  Visit the Echo Merchant Website to test your client against a live x402-powered merchant.
</Card>

## What you need

* An x402 client implementation (see examples below)
* A private key suitable for the network you’re testing

## Step 1 — Pick a client example

Start from one of the reference clients and run it locally:

* TypeScript: <a href="/v1/x402/clients/typescript/axios">Axios</a>, <a href="/v1/x402/clients/typescript/fetch">Fetch</a>
* Python: <a href="/v1/x402/clients/python/httpx">httpx</a>, <a href="/v1/x402/clients/python/requests">requests</a>

These examples already implement the x402 flow (handling `402`, constructing the Payment Payload, retrying with `X-PAYMENT`, and decoding `X-PAYMENT-RESPONSE`).

## Step 2 — Point your client at the Echo Merchant

Visit the [Echo Merchant Website](https://x402.payai.network) to see the supported networks and endpoints for the Echo Merchant.

For example:

```
https://x402.payai.network/api/solana-devnet/paid-content
https://x402.payai.network/api/solana-mainnet/paid-content
https://x402.payai.network/api/base/paid-content
https://x402.payai.network/api/base-sepolia/paid-content
https://x402.payai.network/api/skale-base/paid-content
https://x402.payai.network/api/skale-base-spolia/paid-content
```

## Step 3 — Run and observe

Run the client. You should see the initial `402`, a retry with `X-PAYMENT`, a `200 OK` response, and a decodable `X-PAYMENT-RESPONSE` header. The tokens you sent are refunded automatically and PayAI covers the fees.