> ## 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.

# Quickstart

This page gets you set up quickly as a merchant (server) or a buyer (client).

Choose your language and framework below to get started.

<Note>[Scroll to the end to see all supported blockchain networks.](#supported-networks)</Note>

## Servers (Merchants)

<Tabs>
  <Tab title="TypeScript">
    <CardGroup>
      <Card title="Express" href="/x402/servers/typescript/express" icon="server">
        Quickstart for building an x402-enabled server with Express.
      </Card>

      <Card title="Hono" href="/x402/servers/typescript/hono" icon="server">
        Quickstart for building an x402-enabled server with Hono.
      </Card>

      <Card title="NextJS" href="/x402/servers/typescript/nextjs" icon="server">
        NextJS server quickstart is coming soon.
      </Card>
    </CardGroup>
  </Tab>

  <Tab title="Python">
    <CardGroup>
      <Card title="FastAPI" href="/x402/servers/python/fastapi" icon="server">
        Quickstart for building an x402-enabled server with FastAPI.
      </Card>

      <Card title="Flask" href="/x402/servers/python/flask" icon="server">
        Quickstart for building an x402-enabled server with Flask.
      </Card>
    </CardGroup>
  </Tab>
</Tabs>

## Clients (Buyers)

<Tabs>
  <Tab title="TypeScript">
    <CardGroup>
      <Card title="Axios" href="/x402/clients/typescript/axios" icon="code">
        Quickstart for building an x402 client with Axios.
      </Card>

      <Card title="Fetch" href="/x402/clients/typescript/fetch" icon="code">
        Quickstart for building an x402 client with Fetch.
      </Card>
    </CardGroup>
  </Tab>

  <Tab title="Python">
    <CardGroup>
      <Card title="httpx" href="/x402/clients/python/httpx" icon="code">
        Quickstart for building an x402 client with httpx.
      </Card>

      <Card title="requests" href="/x402/clients/python/requests" icon="code">
        Quickstart for building an x402 client with requests.
      </Card>
    </CardGroup>
  </Tab>
</Tabs>

## Facilitator

All PayAI starter templates include `@payai/facilitator`, which automatically connects to the PayAI facilitator at `https://facilitator.payai.network`. No manual URL configuration needed.

```typescript theme={null}
import { facilitator } from "@payai/facilitator";
import { HTTPFacilitatorClient } from "@x402/core/server";

const facilitatorClient = new HTTPFacilitatorClient(facilitator);
```

The facilitator works immediately on the **free tier**. When you're ready for production, set `PAYAI_API_KEY_ID` and `PAYAI_API_KEY_SECRET` environment variables to authenticate — see [Facilitator Pricing](/x402/facilitators/pricing).

The PayAI facilitator supports the following endpoints:

* `/supported` - see which networks and schemes are supported
* `/verify` - verify that a payment is valid
* `/settle` - settle the payment
* `/discovery/resources` - view the bazaar, a marketplace of merchants

Read the [reference](/x402/reference#7-1-post-%2Fverify) for more information on the facilitator endpoints and responses.

## Supported networks

The PayAI facilitator supports x402 on the following networks:

| Network Name       | V1 Network String    | V2 CAIP-2 ID                              |
| ------------------ | -------------------- | ----------------------------------------- |
| Avalanche          | `avalanche`          | `eip155:43114`                            |
| Avalanche Fuji     | `avalanche-fuji`     | `eip155:43113`                            |
| Base               | `base`               | `eip155:8453`                             |
| Base Sepolia       | `base-sepolia`       | `eip155:84532`                            |
| Polygon            | `polygon`            | `eip155:137`                              |
| Polygon Amoy       | `polygon-amoy`       | `eip155:80002`                            |
| Sei                | `sei`                | `eip155:1329`                             |
| Sei Testnet        | `sei-testnet`        | `eip155:713715`                           |
| SKALE Base         | `skale-base`         | `eip155:1187947933`                       |
| SKALE Base Sepolia | `skale-base-sepolia` | `eip155:324705682`                        |
| Solana             | `solana`             | `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp` |
| Solana Devnet      | `solana-devnet`      | `solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1` |
| X Layer            | `xlayer`             | `eip155:196`                              |
| X Layer Testnet    | `xlayer-testnet`     | `eip155:1952`                             |

## Need help?

<Card title="Join our Community" icon="discord" href="https://discord.gg/eWJRwMpebQ">
  Have questions or want to connect with other developers? Join our Discord server.
</Card>