Autonomous Smart Contract Auditing: AST Traversal and CEI Verification

Description and use

Deterministic AST traversal detects CEI violations in autonomous wallets on Base L2, preventing reentrancy attacks.

Problem

Reentrancy exploits arise when developers violate Checks‑Effects‑Interactions (CEI) by mutating state after external calls, enabling classic reentrancy attacks.

Outcome

AST‑based deterministic checks eliminated CEI violations in autonomous treasury operations on Base L2, preventing reentrancy attacks and enabling safe automated liquidity management.

Workflow

• 1. Decompile or fetch contract source and export AST JSON via solc --ast-compact-json. 2. Run the Python CEIViolationDetector on the AST to identify any Assignment nodes following an external FunctionCall. 3. If violations are found, halt execution locally (hard revert) before sending the transaction. 4. If no violations, allow the autonomous agent to submit the transaction to the network.

Evidence

Polanya berulang: pengembang melanggar aturan Checks-Effects-Interactions (CEI), meninggalkan celah reentrancy klasik di mana mutasi state dilakukan setelah transfer token atau low-level call.

Source

Solusi yang terbukti tahan uji di sistem terdistribusi adalah pendekatan deterministik: Abstract Syntax Tree (AST) Traversal.

Source