Dexter Brings Standard x402 Payments to BNB Smart Chain
Dexter's facilitator now settles x402 payments on BSC using the standard Permit2 protocol and an open-source hardened contract.
Dexter Brings Standard x402 Payments to BNB Smart Chain
FOR IMMEDIATE RELEASE
Dexter's facilitator now settles x402 payments on BSC using the standard Permit2 protocol and an open-source hardened contract.
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BNB Smart ChainBNB Smart Chain processes more daily transactions than any EVM chain except Ethereum. Its dominant stablecoins — Binance-Peg USDT and USDC — do not implement transferWithAuthorization (EIP-3009), the gasless transfer function that x402 uses on Base, Polygon, Arbitrum, Optimism, and Avalanche.
Until now, BSC x402 required workarounds. The Dexter facilitator at x402.dexter.cash now supports BSC in production with two settlement paths: standard Permit2 and a hardened custom contract. Both are live on the same endpoint.
The Gap
AEON has ~573,000 BSC settlements since December 2025 (signer address). They embedded EIP-3009 into a custom contract and forked the entire @x402 SDK. Their client hardcodes their contract address as a string literal. Developers using the standard @x402/evm package cannot use AEON on BSC. Their contract source is not published (proxy).
Milady BSC uses $U by United Stables, a stablecoin with native EIP-3009. Three settlements (example). Users must hold $U.
Pieverse, Unibase, and B402 announced BSC x402 support. None have on-chain evidence of deployment. Full analysis with bytecode decompilation: research report.
Every option required either a forked SDK or a token nobody holds.
Standard Path
Dexter upgraded to @x402/evm v2.9.0, which includes Permit2 routing for EVM chains where EIP-3009 is unavailable. Uniswap's canonical Permit2 contract and the x402ExactPermit2Proxy are both deployed on BSC. Dexter's facilitator advertises assetTransferMethod: "permit2" for eip155:56, and the upstream ExactEvmScheme handles routing automatically.
If a client already works with x402 on Base, it works on BSC through Dexter. No new dependencies. No code changes. Set the network to eip155:56.
Hardened Path
DexterBSCFacilitator is a smart contract deployed behind a TransparentUpgradeableProxy on BSC mainnet. It settles payments through a custom exact-approval scheme that enforces properties Permit2 does not:
- Fee caps at 5% hard maximum, enforced in the contract
- Token allowlist restricting settlement to approved stablecoins
- Emergency pause callable by the contract owner
- Facilitator-only access on
executePayment, preventing front-running of intercepted signatures - ReentrancyGuard (OpenZeppelin v5) on the settlement function
- SafeERC20 for BSC USDT compatibility (does not return bool from
transferFrom)
The contract source is public and verified on BscScan. The exact-approval scheme runs alongside Permit2 on the same facilitator.
Contract: 0x3D56A1A196aC81c959A1be21ABC28c173fB063B8
Source: DexterBSCFacilitator.sol
Technical Details
| Permit2 (standard) | exact-approval (hardened) | |
|---|---|---|
| Scheme | exact | exact-approval |
| Settlement contract | x402ExactPermit2Proxy | DexterBSCFacilitator |
| SDK | @x402/evm or @dexterai/x402 | @dexterai/x402 or custom |
| First payment | Permit2 approval (one-time) | Contract approval (~$0.02 BNB) |
| After that | Gasless signature | Gasless signature |
| On-chain fee cap | No | Yes (5%) |
| Token allowlist | No | Yes |
| Pause | No | Yes |
| Gas | Sponsored by Dexter | Sponsored by Dexter |
Tokens: Binance-Peg USDT (0x55d398326f99059fF775485246999027B3197955) and USDC (0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d). Both 18 decimals.
For Developers
The /supported endpoint returns two kinds for eip155:56, one per settlement path:
curl -s https://x402.dexter.cash/supported | jq '.kinds[] | select(.network == "eip155:56")'
The Dexter SDK (@dexterai/x402) handles both paths automatically through wrapFetch. The upstream @x402/evm package handles Permit2 natively.
Full integration guide: docs.dexter.cash/docs/facilitator-and-chains/bsc
Competitive research with on-chain evidence: dexter.cash/research/bsc-x402.html
About Dexter
Dexter operates the most-used x402 facilitator by settlement volume. The facilitator at x402.dexter.cash settles payments across Solana, Base, Polygon, Arbitrum, Optimism, Avalanche, BSC, and SKALE with gas sponsorship on every chain.
$DEXTER | dexter.cash | @dexteraisol
Resources
- Facilitator: x402.dexter.cash
- BSC Docs: docs.dexter.cash/docs/facilitator-and-chains/bsc
- Research: dexter.cash/research/bsc-x402.html
- Blog: dexter.cash/blog/first-x402-facilitator-bsc-existing-tokens
- Source: github.com/Dexter-DAO/dexter-facilitator
Media Contact: [email protected]