Feature: Multi-Recipient (Batched) Transaction Support to Reduce Fees

[jamespepper81]

Overview

Enhance the BitSleuth Wallet to support sending funds to multiple recipients in a single transaction. This improvement aims to reduce transaction fees through optimized batching and provide a better user experience while lowering network congestion.

Objectives

• Allow users to specify multiple recipient addresses and corresponding amounts within one transaction.
• Minimize total and per-recipient network fees via dynamic fee calculation and batching logic.
• Ensure robust input validation and error handling for all transaction parameters.

Detailed Action Items

• Transaction Model:
  • Update the transaction builder to support assembling multiple outputs in a single transaction (e.g., tx.outputs[] = [{address, amount}, ...]).
  • Ensure transaction serialization/deserialization supports multi-output transactions.
• Fee Optimization:
  • Implement fee calculation logic that distributes network fees efficiently across all recipients to ensure savings versus sequential transactions.
  • Benchmark single vs. multi-recipient sends to validate fee reductions (aim ≥15% savings).
• UI/UX Enhancements:
  • Modify the wallet's send screen to accept and display multiple recipient fields.
  • Provide dynamic validation for address formatting, amount entry, and duplicate/malformed addresses.
  • Add recipient management for easy add/remove/edit and a preview of total outputs and fees before confirmation.
• Backend & API:
  • Update backend endpoints and signing flows to securely handle and process multi-recipient payloads.
  • Ensure responses and audit logs report per-recipient outcomes and transaction IDs.
• Validation:
  • Enforce balance checks, dust threshold enforcement, and output count limits.
• Testing:
  • Unit test building, serialization, and edge cases of multi-recipient transactions.
  • Integration test end-to-end broadcasting, confirmation, and error scenarios.
  • Regression benchmark gas/fee savings.
• Documentation:
  • Update API references and user docs to illustrate new send structure and example multi-recipient payloads.

Acceptance Criteria

• Wallet UI allows users to send to multiple recipients easily in a single flow.
• Sending to multiple recipients in one transaction is reliably confirmed and audit-logged.
• Fee per recipient is at least 15% lower than sequential single sends (demonstrated with tests).
• Robust validation prevents accidental or malicious errors (malformed, duplicated, or dust outputs).
• Developer/API user documentation covers updated usage and example payloads.

---

Labels: enhancement
Project: Wallet
Assignee: jamespepper81
Type: Task