Skip to main content

​
Overview

The Flash Loan Router employs a modular design separating routing logic, lender-specific adapters, and settlement execution. This enables support for multiple flash loan providers while preserving security and predictable execution.

​
Components

The system consists of four main components:
  1. Flash Loan Router - Core orchestrator for flash loans and settlement
  2. Borrower adapters - Lender-specific contracts handling protocol differences
  3. Flash loan lenders - External protocols (Aave, Maker) providing liquidity
  4. CoW Settlement - Target contract executing trades

​
Execution Flow

The system processes settlements through four phases: Phase 1: A solver calls flashLoanAndSettle() with loan specifications and settlement data. Phase 2: The router requests loans sequentially from each borrower adapter, which triggers lender-specific callbacks. Phase 3: Once all loans are received, the router executes the settlement contract with the provided data. Phase 4: Lenders pull repayment from borrower contracts through ERC-20 transfers.

​
Core Security Guarantees

The router maintains these critical properties:
  • Only registered CoW Protocol solvers can call flashLoanAndSettle()
  • Exactly one settlement call per loan request, using unmodified data
  • Sequential loan processing prevents out-of-order execution
  • Atomic execution — all operations succeed or fail together

​
Supported Lenders

  • Aave V3 via AaveBorrower
  • ERC-3156 compatible providers (including Maker) via ERC3156Borrower
New lenders can be added by creating borrower contracts implementing the lender’s callback interface without modifying core router code.
Last modified on March 4, 2026