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April 5, 2026

Gasless x402 Payments Come to BSC

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Gasless x402 Payments Come to BSC

BNB Smart Chain processes more daily transactions than any EVM chain except Ethereum. Its dominant stablecoins, Binance-Peg USDT and USDC, are bridge wrappers with a standard ERC-20 interface and nothing else. They do not implement transferWithAuthorization (EIP-3009), the gasless transfer function that powers x402 settlements on Base, Polygon, Arbitrum, Optimism, Avalanche, and SKALE.

The Dexter facilitator now settles x402 payments on BSC in production. Any ERC-20 token. Settlement gas sponsored by the facilitator.

EIP-3009 chains Payer transferWithAuthorization USDC funds move Seller ✓ BSC — USDT / USDC Payer transferWithAuthorization REVERTS USDT no EIP-3009 ? Dexter settles BSC via Permit2 Payer approve Permit2 sign x402 Proxy settle Seller ✓ Dexter sponsors settlement gas. One-time approval costs ~$0.001 BNB.

How it works

Dexter uses Permit2, Uniswap's canonical token approval contract deployed at the same address on every EVM chain. Instead of calling a transfer function on the token contract directly, the payer approves Permit2 once for the token, then signs an off-chain EIP-712 PermitWitnessTransferFrom authorization for each payment. The facilitator submits the signed authorization to the x402ExactPermit2Proxy, which calls Permit2, which pulls the tokens. The facilitator pays the BNB gas.

The first-time Permit2 approval requires one on-chain transaction from the payer, costing roughly $0.001 in BNB. After that, every payment requires one off-chain signature and zero BNB. The facilitator registers the erc20ApprovalGasSponsoring extension, which relays the payer's pre-signed approval transaction.

For developers: if your client works with x402 on Base, it works on BSC through Dexter. Set the network to eip155:56. The standard @x402/evm package handles Permit2 routing when the facilitator signals assetTransferMethod: "permit2" in the /supported response.

curl -s https://x402.dexter.cash/supported | jq '.kinds[] | select(.network == "eip155:56")'

The BSC x402 landscape

We investigated every project that has claimed or attempted x402 support on BSC. On-chain evidence only.

AEON has ~573,000 settlement transactions since December 2025. They embedded EIP-3009 into a custom smart contract and forked the entire x402 SDK. Their client includes a function called signAuthorizationNoSuperEip3009 with the contract address hardcoded as a string literal. A developer using the standard @x402/evm package cannot use AEON on BSC. The contract source is not published. We decompiled the bytecode and confirmed OpenZeppelin v5 Ownable, Pausable, SafeERC20, and Initializable. No ReentrancyGuard.

Milady BSC uses $U by United Stables, a stablecoin with native EIP-3009 support. Three settlements on-chain. Standard x402 exact scheme, but users must hold $U.

Pieverse, Unibase, and B402 announced BSC x402 support. None have on-chain evidence of deployment. We examined contract addresses, bytecode, and transaction histories. Full methodology in the research report.

DexterDexter AEONAEON MiladyMilady BSC
MechanismPermit2Custom EIP-3009Native EIP-3009 ($U)
USDT/USDCYesYesNo
Any ERC-20YesNoNo
Standard SDKYesNo (fork)Yes
Settlement gaslessYesUnknownUnknown
Source publicCanonical Permit2NoN/A
SettlementsYes~573K3

Technical details

Tokens: Binance-Peg USDT (0x55d398326f99059fF775485246999027B3197955) and USDC (0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d). Both use 18 decimals on BSC, unlike the 6-decimal standard on other chains. The facilitator handles this automatically.

Permit2 flow:

  1. Payer signs and broadcasts an ERC-20 approve transaction for the Permit2 contract (one-time, ~$0.001 BNB)
  2. Payer signs an EIP-712 PermitWitnessTransferFrom authorization (off-chain, no gas)
  3. Facilitator submits the authorization to the x402ExactPermit2Proxy, which settles via Permit2
  4. Recipient receives tokens. Facilitator pays BNB gas.

Gas sponsoring: The facilitator advertises erc20ApprovalGasSponsoring and eip2612GasSponsoring extensions for BSC. Clients that support these extensions can relay the one-time approval through the facilitator. After approval, every payment is gasless. Permit2 and gas sponsoring are available on all supported EVM chains, not just BSC.

Scheme: exact with assetTransferMethod: "permit2" in the facilitator's /supported response. This is the same scheme used on all other EVM chains through Dexter. See the BSC chain docs for integration details.

BSC is live

BSC is the eighth production chain on the Dexter facilitator, joining Solana, Base, Polygon, Arbitrum, Optimism, Avalanche, and SKALE. Settlement gas is sponsored on every chain. The @dexterai/x402 SDK handles BSC automatically through wrapFetch, and the standard @x402/evm package works without modification.

If you are building on BSC and want x402 payments, point at x402.dexter.cash and set your network to eip155:56. That is all it takes.
Research BSC x402 Competitive Analysis
Docs BSC Integration Guide
Facilitator x402.dexter.cash
SDK @dexterai/x402
Source dexter-facilitator
All chains Supported Networks