Web3 developers, wallet
800 USDCryptocurrency Payment System Integration Specification
To enhance payment flexibility and global user accessibility, we plan to integrate native cryptocurrency payment functionality into our website. The system must support asset reception and transaction monitoring across major blockchain networks, with direct connections to each chain’s native RPC nodes (not third-party aggregators), ensuring security, control, and alignment with decentralized principles.
Target Blockchain Networks
The following blockchains and their respective native assets and token standards must be supported:
- Bitcoin (BTC): Native Bitcoin transfers
- Ethereum (ERC-20): Support for USDT, USDC, and other ERC-20 tokens
- BNB Smart Chain (BEP-20): Support for BUSD, USDT-BSC, and other BEP-20 tokens
- TRON (TRC-20): Support for USDT-TRC20 and other TRC-20 tokens
- Solana (SPL): Support for USDC, USDT, and other SPL-standard tokens
- TON (The Open Network): Support for TON native coins and Jetton standard tokens
Core Functional Requirements
1. Wallet Address Generation & Management
- Dynamically generate unique cryptocurrency deposit addresses for each user (isolated wallets or derived addresses)
- Unified multi-chain address management system
2. Real-Time Transaction Monitoring & Confirmation
- Poll or subscribe to block data via native RPC endpoints for each chain
- Detect incoming transactions (both native coin and token transfers)
- Validate transaction legitimacy (e.g., confirmation count, amount, recipient address)
3. Automated Fund Aggregation (Cold Wallet Sweeping)
- Automatically sweep funds to a main/cold wallet when a user’s balance exceeds a predefined threshold
- Handle gas/energy fees during sweeping (with auto-top-up if necessary)
- Support fee management across chains (e.g., energy/bandwidth on BSC/Tron)
4. Withdrawal Functionality
- Enable withdrawals from the main wallet to external addresses for both native coins and tokens
- Provide transaction status tracking and database logging
5. Security & Risk Control
- Private keys must be stored offline; never exposed in application code or environment variables
- Use MPC wallets, HSMs, or hardware signing devices for critical operations
- Implement approval workflows for large withdrawals
6. Data Synchronization & Reconciliation
- Persist on-chain transaction records in the local database
- Provide APIs for transaction status queries
- Support fiat value conversion using exchange rate APIs
7. High Availability Architecture
- Integrate message queues (e.g., Redis + BullMQ) for asynchronous processing and retry mechanisms
Technical Implementation Requirements
- Connect directly to **public or self-hosted full-node RPCs** for each chain. Avoid reliance on third-party gateways (e.g., Alchemy, Infura, TronGrid) to ensure operational autonomy.
- Use officially recommended SDKs per chain:
- Bitcoin**: `bitcoinjs-lib` + self-hosted `bitcoind` node
- Ethereum/BSC: `ethers.js` or `web3.js`
- Tron: `tronweb`
- Solana: `@ solana/web3.js`
- TON: `ton`, `ton-core`
Future Extensibility
- Design a modular architecture to easily add new blockchains (e.g., Polygon, Avalanche)
- Provide internal admin APIs for manual sweeping, balance checks, withdrawal approvals, etc.
This system will serve as a core component of our financial infrastructure and must meet high standards of **security, reliability, and observability** to ensure user asset safety and business continuity.
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70 days22 000 USD
475 70 days22 000 USDHello!
My name is Alexey, I represent a group of developers - NC-1.
For more than five years, we have been creating websites, mobile applications, online stores, ERP/CRM systems, and other e-commerce products.
I offer our team to work on your project:
1. Senior Blockchain Developer - main developer
2. Backend Developer (.NET) - integration with the existing system
3. DevOps Engineer - node setup, security
4. Security Auditor - for code review
5. Project Manager - coordination
… Cases - https://1drv.ms/b/c/b7a0d31a9dae1bc5/EeH6JPdpBbpKtrkA1zFQOIMBAmqUcd_Ptx5tt5p9hBNG-g?e=wXDGHh
Portfolio - https://nc-one.com/case-studies
Sincerely, Alexey M
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1 day800 USD
2318 8 0 1 day800 USDHello,
I’ve carefully reviewed your specification for the cryptocurrency payment system integration. This is a complex but very achievable task — and it aligns perfectly with my background in backend architecture and blockchain integrations.
I can help you design and implement a fully self-hosted, multi-chain payment infrastructure that meets your key principles: security, decentralization, and operational control — without dependency on third-party gateways.
I propose the following approach
1. Wallet Management: Hierarchical deterministic wallet system with chain-specific derivation and address tracking.
2.Monitoring Engine: WebSocket/polling hybrid to track incoming transactions directly from self-hosted RPC nodes.
3. Fund Aggregation: Automated sweeping logic with adaptive gas fee estimation and top-up.
… 4. Withdrawals: Secure, logged, and optionally approval-based workflow with offline signing.
5. APIs & Admin Tools: Internal endpoints for reconciliation, manual triggers, and reporting.
I can handle full development — from architecture design and node setup to production deployment and monitoring.
Let’s discuss your infrastructure preferences (on-prem / cloud / containerized) and start with a technical roadmap and milestone plan.
Best regards,
Nikita Svintcitskiy
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30 days888 USD
475 2 0 30 days888 USDpretty sure doing this not in javascript would fit your goals more
ready to help you out with this
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8 days888 USD
1251 35 1 3 8 days888 USDHello Zhe, we are a small team of professionals with extensive experience in blockchain development, working with web3, working with APIs, and node deployment.
We are the ones you need. Please send us a private message to discuss project development and terms of cooperation.
Thank you.
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7 days800 USD
2874 24 0 7 days800 USDHello!
I have extensive experience developing payment gateways for exchanges and would be glad to create one for your project as well.
My background is highly relevant to your requirements, and I’m ready to start as soon as possible.
If you’re interested, I’d be happy to discuss the details in private.
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15 days850 USD
192 15 days850 USDHello!
I have reviewed your project, everything is clear, I am ready to start working today.
I always try to do not just "as in the technical specifications," but in a way that is truly convenient and of high quality for the client!
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