Cross-chain API

Transfer USDC tokens seamlessly across multiple EVM chains (Sepolia, Amoy, Neon) using burn-and-mint mechanism with automated bridge operations.

📋 Complete Network Details: For comprehensive network configurations, USDC contracts, and chain specifications, see USDC and Chains Guide.

Chain Normalization

The API uses internal chain normalization for processing:

Input Chain	Normalized Chain	Network	Native Token	Chain ID
`sepolia`	`Ethereum`	Sepolia Testnet	ETH	11155111
`amoy`	`Polygon`	Polygon Amoy	POL	80002
`neon`	`Neon`	Neon EVM	NEON	245022926

Initiate Cross-chain Transfer

POST/api/crosschain/initiate

Initiate Cross-chain Transfer

Start a cross-chain transfer by creating a burn log. This is the first step in the burn-and-mint bridge process.

Parameters

user_idnumberrequired

User ID initiating the transfer

amountstringrequired

Amount of USDC to transfer

from_chainstringrequired

Source chain (sepolia, amoy, neon)

to_chainstringrequired

Destination chain (sepolia, amoy, neon)

tokenstringrequired

Token symbol (USDC)

recipient_addressstringrequired

Recipient wallet address on destination chain

return_addressstring

Return address on source chain (for failed transfers)

Request Body

{
  "user_id": 123,
  "amount": "50.00",
  "from_chain": "sepolia",
  "to_chain": "amoy",
  "token": "USDC",
  "recipient_address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "return_address": "0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359"
}

Response

200Transfer initiated successfully

{
  "success": true,
  "data": {
    "log_id": "550e8400-e29b-41d4-a716-446655440000",
    "nonce": "nonce_1734567890123",
    "amount": "50.00",
    "from_chain": "Ethereum",
    "to_chain": "Polygon",
    "token": "USDC",
    "recipient_address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
    "return_address": "0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359",
    "status": "INITIATED",
    "created_at": "2024-01-15T10:30:00Z"
  },
  "message": "Crosschain transfer log created successfully"
}

400Invalid transfer parameters

{
  "error": "Token USDC is not supported on Polygon."
}

curl -X POST https://api.brdz.link/api/crosschain/initiate \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "user_id": 123,
  "amount": "50.00",
  "from_chain": "sepolia",
  "to_chain": "amoy",
  "token": "USDC",
  "recipient_address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "return_address": "0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359"
}'

Confirm Transfer (Update Burn Status)

PATCH/api/crosschain/confirm

Confirm Transfer

Update transfer log after burn transaction is completed. Provides transaction hash and status update.

Parameters

log_idstringrequired

Transfer log ID from initiate response

tx_hashstringrequired

Transaction hash of the burn transaction

statusstringrequired

Transaction status (BURNED, FAILED)

Request Body

{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "status": "BURNED"
}

Response

200Transfer confirmed successfully

{
  "success": true,
  "data": {
    "log_id": "550e8400-e29b-41d4-a716-446655440000",
    "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
    "status": "BURNED",
    "updated_at": "2024-01-15T10:35:00Z"
  },
  "message": "Crosschain log updated successfully"
}

400Invalid confirmation data

{
  "error": "Missing log_id, tx_hash or status"
}

curl -X PATCH https://api.brdz.link/api/crosschain/confirm \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "status": "BURNED"
}'

Mint Tokens

POST/api/crosschain/mint

Mint Tokens

Mint tokens on the destination chain after successful burn. This completes the cross-chain transfer.

Parameters

noncestringrequired

Unique nonce from the transfer log

Request Body

{
  "nonce": "nonce_1734567890123"
}

Response

200Tokens minted successfully

{
  "success": true,
  "tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
  "mint_tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "status": "MINTED",
  "data": {
    "log_id": "550e8400-e29b-41d4-a716-446655440000",
    "status": "MINTED",
    "mint_tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
    "updated_at": "2024-01-15T10:38:00Z"
  }
}

400Mint failed

{
  "error": "Already minted"
}

404Bridge log not found

{
  "error": "Bridge log not found"
}

curl -X POST https://api.brdz.link/api/crosschain/mint \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{"nonce": "nonce_1734567890123"}'

Get USDC Balance

GET/api/crosschain/balance/{chain}/{address}

Get USDC Balance

Check USDC balance on a specific chain for a given wallet address.

Parameters

chainstringrequired

Chain ID (sepolia, amoy, neon) - path parameter

addressstringrequired

Wallet address to check balance for - path parameter

contract_addressstring

USDC contract address (query parameter) - optional, uses environment default if not provided

Response

200Balance retrieved successfully

{
  "chain": "sepolia",
  "address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "balance": "125.50",
  "contract_address": "0x9BF350fBaaA8c7200990B051809334c90778f435",
  "source": "environment"
}

400Invalid chain or address

{
  "error": "Invalid wallet address"
}

curl -X GET https://api.brdz.link/api/crosschain/balance/sepolia/0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY"

# With custom contract address
curl -X GET "https://api.brdz.link/api/crosschain/balance/sepolia/0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D?contract_address=0x9BF350fBaaA8c7200990B051809334c90778f435" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY"

Test Mint (Testnet Only)

POST/api/crosschain/test-mint

Test Mint USDC

Mint test USDC tokens for development and testing purposes. Available on testnets only.

Parameters

chainstringrequired

Chain to mint on (sepolia, amoy, neon)

addressstringrequired

Recipient wallet address

amountstringrequired

Amount of USDC to mint

modestring

Mint mode (manual, metamask) - default: manual

Request Body

{
  "chain": "sepolia",
  "address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "amount": "100.00",
  "mode": "manual"
}

Response

200Test tokens minted successfully

{
  "success": true,
  "tx_hash": "0xtest1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
  "mode": "manual",
  "address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "chain": "sepolia"
}

400Test mint failed

{
  "error": "Invalid wallet address format"
}

curl -X POST https://api.brdz.link/api/crosschain/test-mint \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "chain": "sepolia",
  "address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
  "amount": "100.00",
  "mode": "manual"
}'

Burn Tokens (Backend/MetaMask)

POST/api/crosschain/burn

Burn Tokens

Execute burn transaction either via backend hot wallet or confirm MetaMask transaction.

Parameters

log_idstringrequired

Transfer log ID from initiate response

noncestringrequired

Unique nonce from transfer log

tx_hashstring

Transaction hash (required for metamask mode)

modestring

Burn mode (backend, metamask) - default: backend

Request Body

{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "mode": "backend"
}

Response

200Burn transaction successful

{
  "success": true,
  "data": {
    "log_id": "550e8400-e29b-41d4-a716-446655440000",
    "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
    "status": "BURNED",
    "updated_at": "2024-01-15T10:35:00Z"
  }
}

400Burn failed

{
  "error": "Invalid status. Burn already executed or failed."
}

# Backend mode
curl -X POST https://api.brdz.link/api/crosschain/burn \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "mode": "backend"
}'

# MetaMask mode
curl -X POST https://api.brdz.link/api/crosschain/burn \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "mode": "metamask"
}'

Burn Tokens (Frontend Wallet)

POST/api/crosschain/burn-frontend

Burn Tokens with Frontend Wallet

Execute burn transaction using frontend wallet private key. Use with caution - private keys should be handled securely.

Parameters

log_idstringrequired

Transfer log ID from initiate response

noncestringrequired

Unique nonce from transfer log

private_keystringrequired

Private key of the wallet to execute burn transaction

Request Body

{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "private_key": "0x..."
}

Response

200Frontend burn successful

{
  "success": true,
  "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "status": "BURNED",
  "data": {
    "log_id": "550e8400-e29b-41d4-a716-446655440000",
    "tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
    "status": "BURNED",
    "updated_at": "2024-01-15T10:35:00Z"
  }
}

400Frontend burn failed

{
  "error": "Invalid status. Burn already executed or failed."
}

curl -X POST https://api.brdz.link/api/crosschain/burn-frontend \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY" \
-d '{
  "log_id": "550e8400-e29b-41d4-a716-446655440000",
  "nonce": "nonce_1734567890123",
  "private_key": "0x..."
}'

Get Cross-chain Transaction History

GET/api/crosschain/history/{user_id}

Get Cross-chain Transaction History

Retrieve user's cross-chain transaction history with pagination and filtering options.

Parameters

user_idnumberrequired

User ID to get history for (path parameter)

limitnumber

Maximum records to return (1-100, default: 50)

offsetnumber

Records to skip for pagination (default: 0)

from_chainstring

Filter by source chain (sepolia, amoy, neon)

to_chainstring

Filter by destination chain (sepolia, amoy, neon)

statusstring

Filter by status (INITIATED, BURNED, MINTED, FAILED)

Response

200Transaction history retrieved

{
  "success": true,
  "message": "Crosschain transaction history retrieved successfully",
  "data": {
    "user_id": 123,
    "transactions": [
      {
        "log_id": "550e8400-e29b-41d4-a716-446655440000",
        "nonce": "nonce_1734567890123",
        "user_id": 123,
        "amount": "50.00",
        "token": "USDC",
        "from_chain": "Ethereum",
        "to_chain": "Polygon",
        "status": "MINTED",
        "recipient_address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
        "burn_tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
        "mint_tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
        "created_at": "2024-01-15T10:30:00Z",
        "updated_at": "2024-01-15T10:38:00Z"
      }
    ],
    "pagination": {
      "total_count": 15,
      "limit": 50,
      "offset": 0,
      "has_more": false
    },
    "filters_applied": {
      "from_chain": null,
      "to_chain": null,
      "status": null
    }
  },
  "timestamp": "2024-01-15T10:40:00Z"
}

403Access denied

{
  "success": false,
  "error": {
    "code": "ACCESS_DENIED",
    "message": "You can only access your own crosschain transaction history",
    "details": "Insufficient permissions"
  },
  "timestamp": "2024-01-15T10:40:00Z"
}

curl -X GET "https://api.brdz.link/api/crosschain/history/123?limit=10&status=MINTED" \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY"

Get Cross-chain Transaction Details

GET/api/crosschain/details/{log_id}

Get Cross-chain Transaction Details

Get detailed information about a specific cross-chain transfer by log ID.

Parameters

log_idstringrequired

Transfer log ID (UUID) - path parameter

Response

200Transaction details retrieved

{
  "success": true,
  "message": "Crosschain transaction details retrieved successfully",
  "data": {
    "transaction": {
      "log_id": "550e8400-e29b-41d4-a716-446655440000",
      "nonce": "nonce_1734567890123",
      "user_id": 123,
      "amount": "50.00",
      "token": "USDC",
      "from_chain": "Ethereum",
      "to_chain": "Polygon",
      "status": "MINTED",
      "recipient_address": "0x742d35Cc6834C0532925a3b8D93b3C3e1DEF3e4D",
      "return_address": "0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359",
      "burn_tx_hash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
      "mint_tx_hash": "0xabcdef1234567890abcdef1234567890abcdef1234567890abcdef1234567890",
      "created_at": "2024-01-15T10:30:00Z",
      "updated_at": "2024-01-15T10:38:00Z"
    },
    "requested_by": 123,
    "access_level": "user"
  },
  "timestamp": "2024-01-15T10:40:00Z"
}

404Transaction not found

{
  "success": false,
  "error": {
    "code": "TRANSACTION_NOT_FOUND",
    "message": "Crosschain transaction not found or access denied",
    "details": "Transaction may not exist or you may not have permission to view it"
  },
  "timestamp": "2024-01-15T10:40:00Z"
}

curl -X GET https://api.brdz.link/api/crosschain/details/550e8400-e29b-41d4-a716-446655440000 \
-H "Authorization: Bearer YOUR_JWT_TOKEN" \
-H "x-api-key: YOUR_API_KEY"

Supported Chains & Tokens

Blockchain Networks

Chain ID	Normalized	Network	Native Token	Chain ID	USDC Contract
`sepolia`	`Ethereum`	Sepolia Testnet	ETH	11155111	`0x9BF350fBaaA8c7200990B051809334c90778f435`
`amoy`	`Polygon`	Polygon Amoy	POL	80002	`0xC15239B6B9012F3225f9ebC091C7CE85FF31b983`
`neon`	`Neon`	Neon EVM	NEON	245022926	`0xB5234C0418402775bCA3f73c4B0B5bDd906FCA11`

Bridge Contracts

Network	Bridge Contract
Sepolia	`0x432a3Ab53BEe8657cD5E26Bd9A7251Bbd19B3Fb1`
Polygon Amoy	`0xb04EBd1cE956E5576c5A7A02f74E3DdCFeee564AF`
Neon EVM	`0xF0E6D21447281D3a858B6Bfee045D5c48D2E6065`

Transfer Routes

All chains support bidirectional transfers:

Sepolia ↔ Amoy - ETH ecosystem ↔ Polygon ecosystem
Sepolia ↔ Neon - ETH ecosystem ↔ Solana-compatible EVM
Amoy ↔ Neon - Polygon ecosystem ↔ Solana-compatible EVM

Cross-chain Transfer Flow

Complete Transfer Process

Initiate: Call /crosschain/initiate with transfer details
Burn: Execute burn transaction (backend, MetaMask, or frontend wallet)
Mint: Call /crosschain/mint with nonce to complete transfer

Transfer States

Status	Description	Next Action
`INITIATED`	Transfer initiated, waiting for burn	Execute burn transaction
`BURNED`	Burn transaction confirmed	Call mint endpoint
`MINTED`	Transfer successfully completed	None
`FAILED`	Transfer failed at some step	Contact support

Burn Modes

Mode	Description	Use Case
`backend`	Backend executes burn with hot wallet	Automated transfers
`metamask`	User burns via MetaMask, confirms with tx hash	User-controlled transfers
`frontend`	Frontend executes burn with provided private key	Advanced wallet integration

Estimated Times

Sepolia → Amoy: ~5-8 minutes
Amoy → Neon: ~3-6 minutes
Sepolia → Neon: ~6-10 minutes

Times may vary based on network congestion

Development Testing

Use /crosschain/test-mint to get test USDC tokens for development and testing cross-chain transfers.

Transfer Limits

Minimum transfer: 1.00 USDC
Maximum transfer: 10,000.00 USDC per transaction
Daily limit: 50,000.00 USDC per user

Bridge Fees

Platform fee: 0.1% of transfer amount
Network fees: Paid in native tokens (ETH, POL, NEON)
Minimum fee: $0.10 USD equivalent

Complete Network Details

For comprehensive network configurations, RPC URLs, explorers, and additional chain information, see the USDC and Chains Guide.

Chain Normalization​

Initiate Cross-chain Transfer​

Initiate Cross-chain Transfer

Parameters

Request Body

Response

Confirm Transfer (Update Burn Status)​

Confirm Transfer

Parameters

Request Body

Response

Mint Tokens​

Mint Tokens

Parameters

Request Body

Response

Get USDC Balance​

Get USDC Balance

Parameters

Response

Test Mint (Testnet Only)​

Test Mint USDC

Parameters

Request Body

Response

Burn Tokens (Backend/MetaMask)​

Burn Tokens

Parameters

Request Body

Response

Burn Tokens (Frontend Wallet)​

Burn Tokens with Frontend Wallet

Parameters

Request Body

Response

Get Cross-chain Transaction History​

Get Cross-chain Transaction History

Parameters

Response

Get Cross-chain Transaction Details​

Get Cross-chain Transaction Details

Parameters

Response

Supported Chains & Tokens​

Blockchain Networks​

Bridge Contracts​

Transfer Routes​

Cross-chain Transfer Flow​

Complete Transfer Process​

Transfer States​

Burn Modes​

Estimated Times​

Chain Normalization

Initiate Cross-chain Transfer

Confirm Transfer (Update Burn Status)

Mint Tokens

Get USDC Balance

Test Mint (Testnet Only)

Burn Tokens (Backend/MetaMask)

Burn Tokens (Frontend Wallet)

Get Cross-chain Transaction History

Get Cross-chain Transaction Details

Supported Chains & Tokens

Blockchain Networks

Bridge Contracts

Transfer Routes

Cross-chain Transfer Flow

Complete Transfer Process

Transfer States

Burn Modes

Estimated Times