Move from a confusing revert or failed call to an evidence-backed root-cause diagnosis, reproduction steps, and regression tests.
Turn failed EVM transactions and Solidity reverts into a traceable chain of evidence without relying on confident guesses. Analyzes receipts, calldata, custom error selectors, gas dynamics, and state dependencies.
Evidence-backed root cause report with decoded function selector and revert reason
Minimal reproducible local fork test (Foundry or Hardhat)
Actionable candidate patch and regression-test guidance
Captures chain ID, tx hash or simulation context, block number, target contract, proxy status, function selector, and exact error output.
Records gas used vs gas limit, revert bytes, selector decoding, and stack traces without altering existing test setups.
Categorizes whether the failure is transport, preflight/nonce, gas limit, access control, math/overflow, state precondition, or external call revert.
Formulates a minimal test case against the relevant block height to isolate the exact instruction or state variable triggering the revert.
Proposes a concrete code fix alongside an automated test verifying the fix prevents the failure.
Once the skill is installed, trigger it in Claude Code, Cursor, or your AI assistant with:
“Use the evm-tx-failure-diagnoser skill to investigate this transaction revert on Base (Chain ID 8453). Tx Hash: 0x... The function called was swapExactTokensForTokens, but it reverted with an unrecognized 4-byte selector 0x7939f424.”Join the developer mailing list for new version releases, test scripts, and new Web3 skills. No spam.