Onchain Pay Open API

Binance Onchain-Pay Open API Skill

Call Binance Onchain-Pay Open API endpoints with automatic RSA SHA256 request signing.

Use Cases & Scenarios

This skill is designed for the following scenarios:

1. 💳 Fiat-to-Crypto Purchase & Send

When to use: User wants to buy crypto with fiat currency and send directly to an external on-chain wallet address

• Buy USDT with USD/EUR/TWD using credit card → Send to MetaMask address on BSC
• Purchase BTC with Google Pay → Transfer to hardware wallet
• Buy USDC with P2P → Send to DeFi protocol contract address

Key APIs: trading-pairs → payment-method-list → estimated-quote → pre-order

2. 🔄 Direct Crypto Transfer (Send Primary)

When to use: User has crypto in Binance account and wants to send to external address

• Send existing USDT from Binance Spot to friend's wallet address
• Transfer ETH to Uniswap contract for trading
• Move crypto from Binance to self-custodial wallet (Trust Wallet, Ledger, etc.)

Key APIs: pre-order with SEND_PRIMARY customization

3. 🔗 Cross-Chain Bridge Operations

When to use: User needs to buy crypto on one chain and transfer to another network

• Buy USDC on Ethereum → Bridge to Polygon for lower fees
• Purchase tokens on BSC → Transfer to Base network
• Fiat to crypto on Solana → Send to Arbitrum for DeFi

Key APIs: crypto-network → pre-order with network selection

4. 🏪 Merchant Payment Integration

When to use: Integrate crypto payment gateway for e-commerce or services

• Accept fiat payments and auto-convert to crypto
• Enable "Pay with Crypto" checkout flow
• Process subscription payments with crypto

Key APIs: pre-order with externalOrderId tracking

5. 🤖 Smart Contract Interaction (Onchain-Pay Easy)

When to use: Buy crypto and execute smart contract in one transaction

• Buy USDT and deposit to lending protocol
• Purchase tokens and stake in DeFi pool
• Fiat on-ramp directly to GameFi or NFT marketplace

Key APIs: pre-order with ON_CHAIN_PROXY_MODE customization

6. 📊 Query & Monitoring

When to use: Check order status, available networks, or payment methods

• Monitor order processing status (pending, completed, failed)
• List supported fiat currencies and cryptocurrencies
• Check available payment methods for specific country/amount
• Verify network fees and limits

Key APIs: order, crypto-network, trading-pairs, payment-method-list

Quick Reference

How to Execute a Request

Step 1: Gather credentials

Use the default account (prod) unless the user specifies otherwise. You need:

• BASE_URL: API base URL
• CLIENT_ID: Client identifier
• API_KEY: The sign access token
• PEM_PATH: Absolute path to the RSA private key PEM file

Use the account marked (default) in .local.md.

Step 2: Build the JSON body

Build a compact JSON body from user-specified parameters. Remove any parameters the user did not provide.

IMPORTANT: Address and Network Validation

• address (destination wallet address) and network (blockchain network) are REQUIRED for all pre-order requests
• If the user has configured Default Address and Default Network in .local.md, use them automatically
• If not configured or not provided by user, ASK the user to provide both values before proceeding

Step 3: Sign and call using the bundled script

bash <skill_path>/scripts/sign_and_call.sh \
  "<BASE_URL>" \
  "<API_PATH>" \
  "<CLIENT_ID>" \
  "<API_KEY>" \
  "<PEM_PATH>" \
  '<JSON_BODY>'

Step 4: Return results

Display the JSON response to the user in a readable format.

Authentication

See `references/authentication.md` for full signing details.

Summary:

1. Payload = JSON_BODY + TIMESTAMP (milliseconds)
2. Sign payload with RSA SHA256 using PEM private key
3. Base64 encode the signature (single line)
4. Send as POST with headers: X-Tesla-ClientId, X-Tesla-SignAccessToken, X-Tesla-Signature, X-Tesla-Timestamp, Content-Type: application/json

Parameters Reference

Payment Method List v1 (buy/payment-method-list)

Payment Method List v2 (v2/buy/payment-method-list)

Get all available payment methods without specifying fiat/crypto parameters. Simplified version of v1.

Differences from v1:

• Simpler: No need to specify fiatCurrency, cryptoCurrency, or amount
• Comprehensive: Returns all available payment methods for the merchant
• Use case: Useful for displaying all options before user input

Response Format: Same as v1, returns list of payment methods with their limits and properties.

Estimated Quote (buy/estimated-quote)

\* Recommended: These parameters should be provided. If not specified by user, check .local.md for defaults. If no defaults exist, ask user before proceeding.

Pre-order (buy/pre-order)

Create a buy pre-order and return the redirect link for payment.