For the complete documentation index, see llms.txt. This page is also available as Markdown.

WheelX Payment

WheelX Payment — Technical Documentation

Overview

WheelX Payment is a core primitive of the WheelX cross-chain bridging protocol. It enables users to bridge or swap assets across blockchains by simply sending funds to a generated address — no wallet connection, no transaction signing, and no smart contract interaction required. This makes WheelX Payment ideal for CEX withdrawals, fiat onramps, and headless systems where the sender cannot sign transactions.

The user only needs to perform a standard token transfer to the generated address. WheelX automatically detects the deposit, processes the cross-chain transfer, and delivers funds to the specified destination on the target network.

Key benefits:

  • No wallet connection required

  • No approval transactions or calldata needed

  • Works with any wallet or CEX supporting standard transfers

  • Deterministic address generation with complete refund handling

Demo Guide

How It Works

The WheelX Payment flow consists of three phases:

The integrator requests a deposit address via the WheelX API, specifying the deposit network, deposit token, recipient address on the destination network, and the desired output token. WheelX returns a unique deposit address deterministically generated for the request.

The user sends the specified token amount to the deposit address using a standard token transfer from any wallet or exchange. No special transaction data is required.

WheelX monitors the deposit address on the source chain. Upon detecting a valid deposit, the system processes the cross-chain transfer and delivers funds to the recipient on the destination chain. Funds are credited in the specified output token.

Core Features

Configurable Source Network and Token

Merchants can fully customize the deposit side of the transaction. The API allows specification of:

  • Source (deposit) network — the blockchain where the user will send funds

  • Source token — the asset accepted at the deposit address

This flexibility enables merchants to accept deposits in the assets and networks most convenient for their users, while maintaining control over their treasury management.

Configurable Destination Network and Token

Similarly, merchants define where and how funds are received:

  • Destination network — the blockchain where funds will be delivered

  • Destination token — the asset received by the merchant on the target chain

WheelX handles all cross-chain conversion and bridging automatically, allowing merchants to receive a single, predictable asset on a single chain regardless of where the deposit originated.

Fee Configuration

WheelX provides comprehensive fee management options tailored to the merchant’s business model.

Fixed Fee (WheelX fee)

WheelX charges a fixed service fee per transaction. This fee is transparent and predictable, making it suitable for standard integration scenarios.

Split Fee (Revenue Share)

Merchants can optionally enable a split-fee arrangement with WheelX. In this model, the base WheelX fee and the merchant’s markup are configured separately, allowing for customized revenue sharing agreements.

Merchant Markup

Merchants may add an additional fee on top of the WheelX base fee. This markup is deducted from the deposit amount before final crediting. The merchant markup can be configured at the account level via the WheelX dashboard or programmatically through the API.

Optional Fee Sponsorship

Merchants have the choice to:

  • Pass through fees — End users pay standard WheelX fees plus any merchant markup

  • Absorb fees — Merchant sponsors the entire fee, offering a fee-free experience to end users

This B-side fee flexibility allows merchants to optimize their pricing strategy based on user acquisition costs and competitive positioning.

Refund Handling

When a deposit fails to complete successfully for any reason, WheelX implements a robust refund mechanism. The refund address is specified at deposit address creation time. Refunds are processed automatically, returning the original deposited funds to the designated refund address on the source chain.

Key refund scenarios include:

  • Insufficient deposited amount

  • Unsupported token deposit

  • Chain congestion exceeding processing time limits

  • Router-level failures

Refund transactions are tracked and can be monitored through the Deposit API and webhook notifications.

Deposit Status Tracking

WheelX provides comprehensive deposit status information to integrators. The status can be polled via the API or received in real-time through webhook events.

Status values:

  • pending — Deposit detected, awaiting confirmation

  • completed — Funds successfully delivered to destination

  • failed — Deposit failed, refund initiated

  • refunded — Refund completed

The Deposit API returns detailed information including:

  • Transaction hash on source chain

  • Source token and amount

  • Destination network

  • Destination token and received amount

  • Fee breakdown

  • Final status with timestamp

Exception Handling

WheelX includes robust exception handling for edge cases:

On-chain congestion

When a target network experiences high traffic, WheelX automatically monitors for confirmation and retries fills with appropriate gas adjustments. Merchants can also trigger the acceleration feature for immediate expedited processing.

Router stalling

In the rare event that a route becomes temporarily unresponsive, WheelX automatically contacts the route provider to resolve the issue. The system maintains redundancy across multiple routing partners to minimize disruption.

Invalid deposits

Deposits that do not match the configured token (e.g., sending ETH when USDC is expected) are automatically rejected and refunded to the specified refund address.

Balance Reconciliation and Sweeping

After deposits are processed and credited on the destination chain, deposit addresses are periodically swept to consolidate remaining balances. This maintains monitoring efficiency and ensures no funds are left stranded on source chain addresses.


API Reference

POST /v1/quote

Quote

GET /v1/order/{request_id}

Get Order

Get Orders

Query cross-chain orders — acts as a transaction explorer. Supports filtering by address, chain, token, status, bridge, tx hash, and time range. Table structure: Quote LEFT JOIN Transaction LEFT JOIN ExternalTransaction - Transaction/ExternalTransaction hold destination-chain fill info - fill_tx_hash = COALESCE(Transaction.tx_hash, ExternalTransaction.tx_hash) - Status: same-chain = filled; cross-chain depends on Transaction/ExternalTransaction state When an address filter is provided, relay deposit history from the Relay API is also fetched and merged with local DB results (deduplicated by bridge_order_id). When `use_deposit_address=True`, only orders that went through a deposit address flow (Quote.deposit is not null) are returned. The `address` parameter still filters by sender.

GET /v1/chain-info

Chain Info

Use Cases

Centralized Exchange (CEX) Withdrawals

Allow users to withdraw funds from your exchange directly to a deposit address. WheelX automatically bridges the funds to the destination chain specified by the user. No additional wallet connection or signing is required from the end user.

Fiat Onramps

Accept fiat deposits, convert to crypto, and send funds to a deposit address. The onramp provider only needs to support standard token transfers — no smart contract integration is required.

Payment Processing

Generate unique deposit addresses for each customer or invoice. Accept payments in multiple cryptocurrencies across multiple chains while settling in a single asset on a single chain.

Cross-Chain Treasury Management

Collect funds from various blockchains and automatically consolidate them into a preferred asset on a preferred chain, simplifying treasury operations and reducing manual intervention.

B2B Settlement

Enable business partners to settle payments using their preferred blockchain and token, while receiving funds in your treasury asset of choice. The merchant markup feature allows you to pass settlement costs to payers or absorb them as a business incentive.

Conclusion

WheelX Payment provides a complete solution for cross-chain asset reception with flexible fee configuration, robust error handling, and comprehensive monitoring capabilities. The system is designed to integrate seamlessly into existing applications while providing enterprise-grade reliability for cross-chain payments.

Supported Chains&Tokens

Network
Token
Contract Address

Ethereum

ETH

0x0000000000000000000000000000000000000000

Ethereum

USDC

0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48

Ethereum

USDT

0xdac17f958d2ee523a2206206994597c13d831ec7

Base

ETH

0x0000000000000000000000000000000000000000

Base

USDC

0x833589fcd6edb6e08f4c7c32d4f71b54bda02913

BNB Chain

BNB

0x0000000000000000000000000000000000000000

BNB Chain

USDT

0x55d398326f99059ff775485246999027b3197955

Solana

USDC

EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v

Solana

USDT

Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB

Tron

USDT

TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t

Last updated

Was this helpful?