x402 facilitator
Networks and fee payers
Which chains are hosted, their ids, USDC addresses and who pays the fee.
| Network | CAIP-2 id | Hosted | USDC |
|---|---|---|---|
| Hedera | hedera:mainnet | Mainnet | 0.0.456858 |
| Hedera testnet | hedera:testnet | Testnet | 0.0.429274 |
| Base Sepolia | eip155:84532 | Testnet | 0x036CbD53842c5426634e7929541eC2318f3dCF7e |
| Solana devnet | solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1 | Testnet | 4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU |
Fee payers change. Read them from GET /supported instead of hard-coding them.
What a settlement costs us
| Chain | Fee, roughly |
|---|---|
| Hedera | about 0.014 HBAR |
| Base | a fraction of a cent in ETH |
| Solana | about 0.000005 SOL |
Signing details
- Hedera: the buyer signs a transfer with our account as the transaction's payer. The buyer's account needs USDC associated.
- Base Sepolia: EIP-3009
transferWithAuthorization. The token's signing name isUSDC, version2. (Base mainnet USDC signs asUSD Coin.) - Solana: the buyer partially signs a USDC transfer and we add the fee-payer signature. The receiver needs a USDC token account.
Get testnet funds
- HBAR and a Hedera testnet account: portal.hedera.com
- Testnet USDC on Base Sepolia and Solana devnet: faucet.circle.com. Circle's faucet has no Hedera; our facilitator settles any HTS token, so a token you create on testnet works for trying it out.
- Base Sepolia ETH: Coinbase faucet
- Devnet SOL: faucet.solana.com