Networks & Token Support

​

Network Identifiers (CAIP-2)

• EVM networks: eip155:<chainId> — any EVM chain is supported (e.g., eip155:8453 for Base)
• Solana: solana:<genesisHash> (first 32 bytes of the genesis block hash)
• TON (TVM): tvm:<workchain> (e.g., tvm:-239 for mainnet, tvm:-3 for testnet)
• Algorand: algorand:<reference> — URL-safe base64 of the genesis hash, first 32 characters (Algorand CAIP-2 profile)
• Stellar: stellar:<network> (pubnet or testnet)
• Aptos: aptos:<chainId> (e.g., aptos:1 for mainnet)
• Hedera: hedera:<network> (mainnet or testnet)
• Keeta: keeta:<networkId> (e.g., keeta:21378 for mainnet)
• NEAR: near:<network> (mainnet or testnet)
• Concordium: ccd:<genesisHash> (e.g., ccd:9dd9ca4d19e9393877d2c44b70f89acb for mainnet)
• XRPL: xrpl:<networkId> (e.g., xrpl:0 for mainnet, xrpl:1 for testnet)
• Cardano: cardano:<network> (mainnet, preprod, or preview). CIP-34 aliases (cip34:1-764824073, cip34:0-1, cip34:0-2) are accepted as input aliases and normalized to the canonical form.

​

Token Support

​

Production Network Support

• Protocol support means x402 can express payment requirements and payloads for that network.
• Runtime support means your server can register the network and use a compatible scheme implementation.
• Production support means you also have a facilitator path that works for your deployment model: a production facilitator provider, a self-hosted facilitator, or self-facilitation.

​

EVM: Asset Transfer Methods

​

EVM: Batch settlement (batch-settlement)

​

Specifying Payment Amounts

1. Price String (e.g., "$0.01") — The system uses the chain’s default stablecoin. Only works on chains with a configured default.
2. TokenAmount — Specify exact amountInAtomicUnits + asset address. Works on any chain with no configuration needed.

​

Using Custom ERC-20 Tokens

1. Token Address: The contract address of your ERC-20 token
2. EIP-712 Name: The token’s name for EIP-712 signatures
3. EIP-712 Version: The token’s version for EIP-712 signatures

1. Name: Read the name() function - Example on Basescan
2. Version: Read the version() function - Example on Basescan

{
  eip712: {
    name: "USD Coin",    // From name() function
    version: "2"         // From version() function
  }
}

​

Default Assets for Dollar-String Pricing

​

EVM

​

Solana (SVM)

​

TON (TVM)

​

Algorand (AVM)

​

Stellar

​

Aptos

​

Hedera

​

Keeta

​

NEAR

​

Cardano

​

Adding Support for New Networks

1. Runtime Registration — use any network in your own server code without modifying the x402 source. No PR required.
2. Contributing a New Default Asset — upstream a chain so it appears in the default-asset tables above and supports "$0.01" dollar-string pricing out of the box. Requires a PR updating the TypeScript, Go, and Python SDK registries.

​

Runtime Registration

import { x402ResourceServer, HTTPFacilitatorClient } from "@x402/core/server";
import { ExactEvmScheme } from "@x402/evm/exact/server";

const facilitatorClient = new HTTPFacilitatorClient({
  url: "https://your-facilitator.com"  // Facilitator that supports your network
});

const server = new x402ResourceServer(facilitatorClient);
server.register("eip155:*", new ExactEvmScheme());

const routes = {
  "GET /api/data": {
    accepts: [{
      scheme: "exact",
      price: "$0.001",
      network: "eip155:43114",  // Avalanche mainnet
      payTo: "0xYourAddress",
    }],
  },
};

import (
    x402http "github.com/x402-foundation/x402/go/v2/http"
    evm "github.com/x402-foundation/x402/go/v2/mechanisms/evm/exact/server"
)

facilitatorClient := x402http.NewHTTPFacilitatorClient(&x402http.FacilitatorConfig{
    URL: "https://your-facilitator.com",
})

schemes := []ginmw.SchemeConfig{
    {Network: x402.Network("eip155:43114"), Server: evm.NewExactEvmScheme()},  // Avalanche
}

from x402.http import FacilitatorConfig, HTTPFacilitatorClient, PaymentOption
from x402.http.types import RouteConfig
from x402.mechanisms.evm.exact import ExactEvmServerScheme
from x402.server import x402ResourceServer

facilitator = HTTPFacilitatorClient(
    FacilitatorConfig(url="https://your-facilitator.com")
)

server = x402ResourceServer(facilitator)
server.register("eip155:43114", ExactEvmServerScheme())  # Avalanche mainnet
routes: dict[str, RouteConfig] = {
    "GET /api/data": RouteConfig(
        accepts=[
            PaymentOption(
                scheme="exact",
                price="$0.001",
                network="eip155:43114",
                pay_to="0xYourAddress",
            ),
        ],
    ),
}

• Use CAIP-2 format: eip155:<chainId> for any EVM network
• The scheme implementation handles the network automatically
• You only need a facilitator that supports your target network, or you can run your own facilitator, or self-facilitate

​

Production checklist for a new EVM network

1. You know which token you want to accept and whether it uses EIP-3009 or Permit2.
2. You have a production settlement path for that network:
   • a managed production facilitator,
   • a self-hosted facilitator,
   • or self-facilitation.
3. You have decided whether to use explicit TokenAmount pricing or contribute a default asset for dollar-string pricing.

​

Contributing a New Default Asset

​

Facilitators

​

x402.org Facilitator

• Supports: eip155:84532 (Base Sepolia), solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1 (Solana Devnet), stellar:testnet (Stellar Testnet), aptos:2 (Aptos Testnet), hedera:testnet (Hedera Testnet), xrpl:1 (XRPL Testnet)
• Notes: Recommended for testing and development. This is the default facilitator in the x402 packages and requires no setup.

​

Production Facilitators

​

Quick Reference

​

Running Your Own Facilitator

1. Access to an RPC endpoint for your target network
2. A wallet with native tokens for gas sponsorship
3. The x402 facilitator code

​

Getting Help

• Join the x402 Slack community
• Check the x402 GitHub repository

​

Summary

• Any EVM chain is supported via eip155:<chainId> — plus Solana, TON (TVM), Algorand (AVM), Stellar, Aptos, Hedera, Keeta, NEAR, Concordium, XRPL, and Cardano
• Default assets are a convenience for "$0.01" dollar-string pricing; explicit TokenAmount works on any chain
• Any ERC-20 token works on any EVM facilitator (via EIP-3009 or Permit2)
• CAIP-2 identifiers provide unambiguous cross-chain support

• Quickstart for Sellers — Start accepting payments on supported networks
• Core Concepts — Learn how x402 works under the hood
• Facilitator — Understand the role of facilitators
• MCP Server — Set up AI agents to use x402 payments