Deploy Wallet (Verify)

Compute deterministic wallet addresses and deployment fees before on-chain deployment

Computes deterministic wallet addresses, calculates deployment and funding fees, and validates the payment payload. Call this before /deploy/settle to confirm addresses and costs.

Two flows are available depending on how the payer signs the transaction.

EOA Deploy Verify

POST /deploy/verify

The payer signs EIP-712 TransferWithAuthorization payloads covering the deployment fee and optional funding amounts.

Request Body

Field	Type	Required	Description
paymentPayload	PaymentPayload[]	Yes	Array of signed payments: 1 fee payload + up to 10 funding payloads
paymentRequirements	object	Yes	Network and deployment configuration
paymentRequirements.network	string	Yes	Target network ("bsc" or "base")
paymentRequirements.relayerContract	string	Yes	b402 Relayer contract address
paymentRequirements.deployment	object	Yes	Deployment parameters
paymentRequirements.deployment.ownerAddress	string	Yes	Owner of the wallets to deploy
paymentRequirements.deployment.salts	string[]	Yes	1-10 salts for deterministic address computation
paymentRequirements.deployment.fundingRequested	boolean	Yes	Whether to fund wallets after deployment
paymentRequirements.deployment.token	string	Yes	ERC-20 token contract address for fees and funding

Response (200)

Field	Type	Description
isValid	boolean	Whether the deployment can proceed
payer	string	Recovered signer address
wallets	object[]	Computed wallet details
wallets[].address	string	Deterministic wallet address
wallets[].salt	string	Salt used for this wallet
wallets[].owner	string	Owner address
wallets[].fundingAmount	string	Amount to fund this wallet (wei), "0" if funding not requested
deploymentFee	string	Fee for deploying all wallets (wei)
fundingFees	string	Total funding amount across all wallets (wei)
totalFees	string	deploymentFee + fundingFees (wei)
invalidReason	string | null	Reason for failure if isValid is false

cURL

curl -X POST https://facilitatorv3.b402.ai/deploy/verify \
  -H "Content-Type: application/json" \
  -d '{
    "paymentPayload": [
      {
        "token": "0x55d398326f99059fF775485246999027B3197955",
        "payload": {
          "authorization": {
            "from": "0xAbC1234567890aBcDeF1234567890AbCdEf123456",
            "to": "0xE91b564EB8DFF305Ff8efA332f84c487b9da5171",
            "value": "500000000000000000",
            "validAfter": 1709251200,
            "validBefore": 1709254800,
            "nonce": "0xaaa...fee_nonce"
          },
          "signature": "0x...fee_signature"
        }
      },
      {
        "token": "0x55d398326f99059fF775485246999027B3197955",
        "payload": {
          "authorization": {
            "from": "0xAbC1234567890aBcDeF1234567890AbCdEf123456",
            "to": "0xE91b564EB8DFF305Ff8efA332f84c487b9da5171",
            "value": "1000000000000000000",
            "validAfter": 1709251200,
            "validBefore": 1709254800,
            "nonce": "0xbbb...funding_nonce"
          },
          "signature": "0x...funding_signature"
        }
      }
    ],
    "paymentRequirements": {
      "network": "bsc",
      "relayerContract": "0xE91b564EB8DFF305Ff8efA332f84c487b9da5171",
      "deployment": {
        "ownerAddress": "0xAbC1234567890aBcDeF1234567890AbCdEf123456",
        "salts": ["0x1234...master_salt"],
        "fundingRequested": true,
        "token": "0x55d398326f99059fF775485246999027B3197955"
      }
    }
  }'

TypeScript

const response = await fetch("https://facilitatorv3.b402.ai/deploy/verify", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    paymentPayload: [feePayload, ...fundingPayloads],
    paymentRequirements: {
      network: "bsc", // or "base"
      relayerContract: "0xE91b564EB8DFF305Ff8efA332f84c487b9da5171",
      deployment: {
        ownerAddress: wallet.address,
        salts: [masterSalt],
        fundingRequested: true,
        token: "0x55d398326f99059fF775485246999027B3197955",
      },
    },
  }),
});

const result = await response.json();

if (result.isValid) {
  console.log("Wallets to deploy:", result.wallets);
  console.log("Total fees:", result.totalFees);
  // Proceed to /deploy/settle
} else {
  console.error("Verification failed:", result.invalidReason);
}

---

Smart Wallet Deploy Verify

POST /deploy/wallet/verify

For smart wallet payers, the facilitator builds an unsigned UserOp instead of requiring pre-signed EIP-712 payloads. No paymentPayload is needed in the request.

Request Body

Field	Type	Required	Description
paymentRequirements	object	Yes	Network and deployment configuration
paymentRequirements.network	string	Yes	Target network ("bsc" or "base")
paymentRequirements.deployment	object	Yes	Deployment parameters
paymentRequirements.deployment.ownerAddress	string	Yes	Owner of the wallets to deploy
paymentRequirements.deployment.salts	string[]	Yes	1-10 salts for deterministic address computation
paymentRequirements.deployment.token	string	Yes	ERC-20 token contract address for fees and funding
paymentRequirements.deployment.payerAddress	string	Yes	Smart wallet address paying for deployment

Response (200)

Returns the same fields as the EOA response, plus:

Field	Type	Description
userOp	object	Unsigned ERC-4337 UserOperation for the client to sign
userOpHash	string	Hash of the UserOp that the client must sign

All other fields (isValid, payer, wallets, deploymentFee, fundingFees, totalFees, invalidReason) are identical to the EOA response.

cURL

curl -X POST https://facilitatorv3.b402.ai/deploy/wallet/verify \
  -H "Content-Type: application/json" \
  -d '{
    "paymentRequirements": {
      "network": "bsc",
      "deployment": {
        "ownerAddress": "0xAbC1234567890aBcDeF1234567890AbCdEf123456",
        "salts": ["0x1234...master_salt"],
        "token": "0x55d398326f99059fF775485246999027B3197955",
        "payerAddress": "0x...nexus_smart_wallet"
      }
    }
  }'

TypeScript

const response = await fetch("https://facilitatorv3.b402.ai/deploy/wallet/verify", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    paymentRequirements: {
      network: "bsc", // or "base"
      deployment: {
        ownerAddress: ownerAddress,
        salts: [masterSalt],
        token: "0x55d398326f99059fF775485246999027B3197955",
        payerAddress: smartWalletAddress,
      },
    },
  }),
});

const result = await response.json();

if (result.isValid) {
  console.log("UserOp hash to sign:", result.userOpHash);
  console.log("Wallets to deploy:", result.wallets);
  // Sign userOpHash, then call /deploy/wallet/settle
} else {
  console.error("Verification failed:", result.invalidReason);
}

---

Deterministic Address Computation

Wallet addresses are computed deterministically using CREATE2. Given the same owner, salt, and factory contract, the address is always the same, even before deployment.

Master Wallet Salt

The master wallet salt is derived from the owner address:

masterSalt = keccak256("b402-" + reversed(normalizedOwnerAddress))

Where normalizedOwnerAddress is the checksummed owner address with the 0x prefix removed, reversed as a string.

The master wallet is a special wallet that serves as the primary wallet for an owner. Each owner has exactly one deterministic master wallet. Sub-wallets use arbitrary salts.

Deployment Fee

A flat deployment fee is charged per wallet deployed. The fee is denominated in the token specified in paymentRequirements.deployment.token. The verify response includes the exact deploymentFee so you can confirm the cost before settling.

Optional Funding

When fundingRequested is true (EOA flow), the facilitator will fund each deployed wallet with the amounts specified in the funding payment payloads. Each funding payload corresponds to one wallet in the salts array, in order.

Error Codes

Code	HTTP Status	Description
validation_error	400	Missing required fields, invalid salt format, or too many salts (max 10)
signature_error	400	EIP-712 signature is malformed or recovery failed
payment_verification_error	400	Insufficient balance, allowance too low, or token not whitelisted
blockchain_error	500	Failed to compute addresses or read on-chain state

Related

• Deploy Wallet (Settle) - Execute deployment after verification
• Get Master Wallet - Look up an owner’s master wallet
• List Wallets - List all wallets for an owner