B4
Blocky402

Networks & Assets

Blocky402 supports multiple blockchain networks for x402 payments. The hosted testnet facilitator is fully operational; the hosted mainnet API currently advertises Hedera Mainnet, with additional mainnet chains available when self-hosting.

The authoritative, always-current list is whatever the facilitator advertises at GET /supported (testnet) or GET /supported (mainnet). The networks below mirror those responses.

Testnet Networks (Available Now)

These are the networks the hosted testnet facilitator (https://api.testnet.blocky402.com) currently advertises.

Polygon Amoy

  • Network ID: eip155:80002
  • Chain ID: 80002
  • Type: EVM (Ethereum Virtual Machine)
  • Status: ✅ Operational
  • Assets: USDC, USDT

Solana Devnet

  • Network ID: solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1
  • Type: SVM (Solana Virtual Machine)
  • Status: ✅ Operational
  • Fee-payer: advertised in extra.feePayer / signers["solana:*"][0]
  • Assets: USDC, USDT

Hedera Testnet

  • Network ID: hedera:testnet
  • Type: Hedera Hashgraph
  • Status: ✅ Operational
  • Fee-payer: advertised in extra.feePayer / signers["hedera:*"][0]
  • Assets: HBAR (native), HTS tokens

Additional Networks (Self-Host Only)

These networks are implemented in the codebase and can be enabled via configuration when self-hosting, but they are not advertised by the hosted testnet facilitator. Always check /supported for what a given facilitator actually accepts.

  • Base Sepolia (eip155:84532) - Chain ID: 84532
  • Arbitrum Sepolia (eip155:421614) - Chain ID: 421614
  • Optimism Sepolia (eip155:11155420) - Chain ID: 11155420
  • Avalanche Fuji (eip155:43113) - Chain ID: 43113
  • Ethereum Sepolia (eip155:11155111) - Chain ID: 11155111

Mainnet Networks

Hosted mainnet (https://api.blocky402.com)

The hosted mainnet facilitator currently advertises:

Hedera Mainnet

  • Network ID: hedera:mainnet
  • Type: Hedera Hashgraph
  • Status: ✅ Operational (hosted)
  • Fee-payer: advertised in extra.feePayer / signers["hedera:*"][0]
  • Assets: HBAR (native), HTS tokens

Self-host mainnet (configuration required)

The following mainnet networks are implemented in the codebase and can be enabled when self-hosting. They are not advertised by the hosted mainnet facilitator unless you deploy and configure them yourself:

  • Ethereum Mainnet (eip155:1) - Chain ID: 1
  • Base Mainnet (eip155:8453) - Chain ID: 8453
  • Polygon Mainnet (eip155:137) - Chain ID: 137
  • Solana Mainnet (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp)
  • Arbitrum Mainnet (eip155:42161) - Chain ID: 42161
  • Optimism Mainnet (eip155:10) - Chain ID: 10
  • Avalanche Mainnet (eip155:43114) - Chain ID: 43114

Supported Assets

EVM and Solana networks support:

  • USDC (USD Coin) - Primary stablecoin
  • USDT (Tether USD) - Secondary stablecoin

Hedera supports:

  • HBAR (native, asset id 0.0.0)
  • HTS tokens (pass the token id as the asset)

Asset contract addresses vary by network. Check the network-specific documentation or use the /supported endpoint to get current asset addresses.

Facilitator Architecture

Blocky402 runs a single x402 facilitator that registers one exact scheme per network family using the official x402 SDK packages:

  • EVM networks via @x402/evm
  • SVM (Solana) networks via @x402/svm
  • Hedera networks via @x402/hedera

The facilitator automatically routes each request to the right scheme based on the payment’s network. You don’t need to specify which scheme to use — just pick a network the facilitator advertises in /supported.

Network Selection

When creating a payment, specify the network in your payment requirements:

{
  "scheme": "exact",
  "network": "eip155:80002",  // a network advertised by /supported
  "amount": "1000000",        // atomic units of the asset
  "asset": "0xA0b86a33E6441b8C4C8C0C3A0b86a33E6441b8C4C",  // network-specific asset address
  "payTo": "0x742d35Cc6634C0532925a3b8D4C80700d4C9C7e7",
  "maxTimeoutSeconds": 300,
  "extra": {}                 // required; for Solana/Hedera pass { feePayer } from /supported
}

Getting Network Information

Use the /supported endpoint to get the current list of supported networks:

curl https://api.testnet.blocky402.com/supported
{
  "kinds": [
    { "scheme": "exact", "network": "eip155:80002", "x402Version": 2 },
    {
      "scheme": "exact",
      "network": "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1",
      "x402Version": 2,
      "extra": { "feePayer": "7B6Q2MvcJvNcy1A13wHmAzmmdo3L8DVriaXML7bvkojm" }
    },
    {
      "scheme": "exact",
      "network": "hedera:testnet",
      "x402Version": 2,
      "extra": { "feePayer": "0.0.7162784" }
    }
  ],
  "extensions": [],
  "signers": {
    "eip155:*": ["0xDCF7D72C2eE049DE4269ac6AAf925F33efdA18de"],
    "solana:*": ["7B6Q2MvcJvNcy1A13wHmAzmmdo3L8DVriaXML7bvkojm"],
    "hedera:*": ["0.0.7162784"]
  }
}

Network-Specific Considerations

EVM Networks (Polygon, Base, Arbitrum, Optimism, Avalanche)

  • Use standard Ethereum addresses (0x…)
  • Gas fees apply (testnet tokens available from faucets)
  • Supports standard ERC-20 tokens (USDC, USDT)

Solana Networks

  • Use Solana addresses (base58 encoded)
  • Transaction fees are minimal
  • The facilitator acts as fee-payer; pass extra.feePayer from /supported
  • Supports SPL tokens (USDC, USDT)

Hedera

  • Use Hedera account ids (0.0.x)
  • The facilitator acts as fee-payer; the payer signs a TransferTransaction
  • Pass extra.feePayer from /supported (signers["hedera:*"][0])
  • Supports HBAR and HTS tokens

Testnet Faucets

Get testnet tokens for development:

Network Status

Check the health of the API and networks:

curl https://api.testnet.blocky402.com/health

For real-time network status, see the API Health endpoint.

Adding New Networks

Blocky402 is designed to easily support new networks. If you need a network that’s not currently supported, please open an issue on GitHub.