Web3 EVM Debugger & Auditor MCP

EVM calldata decoding, debug trace revert pinpointing, storage slot layout mapping, and smart contract reentrancy auditing.

Part of the WHAM ENGINE fleet of deterministic AI agent micro-services with automated Base L2 HTTP 402 (x402) USDC micropayments.

Tools Included in this Suite (6 Tools)

• evm_trace_call_revert_debugger: Parses Geth/Nethermind debug_traceTransaction call trees, pinpointing the exact depth, instruction opcode, sub-contract, and revert message of failed calls.
• smart_contract_reentrancy_auditor: Symbolic execution analyzer scanning Solidity ASTs for cross-function reentrancy, check-effects-interaction violations, and read-only reentrancy in view functions.
• decode_evm_calldata: Decodes raw 4-byte function selectors and hex calldata into human-readable method signatures, types, and named arguments.
• evm_storage_slot_layout_calculator: Calculates exact 32-byte EVM storage slots for complex Solidity state variables (nested mappings, dynamic arrays, packed structs) according to ABI specification.
• solidity_assembly_yul_sanitizer: Scans inline Yul assembly in Solidity smart contracts for uninitialized memory pointer bugs, 64-bit clean memory corruption, and memory expansion gas bombs.
• eip1271_smart_contract_signature_verifier: Verifies EIP-1271 signatures on smart contract wallets (Safe, Argent, Kernel, Biconomy) using eth_staticcall validation with gas safeguards.

Recommended Workflow

An auditor agent investigates an on-chain transaction revert -> decodes the calldata -> traces the revert step-by-step through internal calls -> maps impacted storage slots -> audits the target contract for reentrancy bugs.

Quickstart Configuration

Add this server to your claude_desktop_config.json:

{
  "mcpServers": {
    "web3-evm-debugger-mcp": {
      "command": "npx",
      "args": ["-y", "@whambammy/web3-evm-debugger-mcp"],
      "env": {
        "PAYMENT_WALLET": "0x9793E7269b3301893318dEa8338576Ba612F39B3",
        "BASE_RPC_URL": "https://mainnet.base.org"
      }
    }
  }
}

Or connect the skill directly via Smithery:

smithery skill add whambammy/web3-evm-debugger-mcp