Fuzz Solidity smart contracts with stateful property-based testing using Echidna.
npx skills add https://github.com/andresdefi/cryptoskills --skill echidna-andresdefi
Please help me install this Agent Skill. Skill: echidna Source: https://github.com/andresdefi/cryptoskills/tree/main/skills/echidna Command: npx skills add https://github.com/andresdefi/cryptoskills --skill echidna-andresdefi
echidna_* invariant functions, assertion-mode tests, and optimization-mode checks for Solidity contracts. - Configuration & Corpus Management: Tune testLimit, seqLen, shrinkLimit, workers, and dictionaries, and persist corpora across runs for faster convergence. - Foundry & CI Integration: Run Echidna alongside Forge tests with correct remappings, crytic-compile arguments, and GitHub Actions workflows. - Use Case: Before an audit of a lending protocol, run a deep overnight campaign with 5M transactions and long sequences to verify collateralization and solvency invariants hold under arbitrary user interactions. ## Quick Start Ask the agent to write an Echidna property test harness for your Solidity contract and generate a tuned echidna.yaml config to run it.High-intent search queries and answers about installing and using this skill.
Create public or external functions prefixed with echidna_ that take no arguments and return bool. Echidna calls random contract functions between property checks and reports a failure when a property returns false.
Property mode checks echidna_* functions returning bool, while assertion mode catches assert() failures and Solidity panics like division by zero or overflow. They are separate testing strategies selected via the testMode config option.
Echidna integrates with Foundry via cryticArgs using --compile-force-framework foundry, but it does not support vm cheatcodes like vm.prank or vm.warp. Use sender addresses in config and constructor setup instead.
This happens when functions are internal or private, take arguments, lack the echidna_ prefix in property mode, or the wrong testMode is configured. Properties must be public or external with no arguments returning bool.
Install solc-select, then run solc-select install and use with the version matching your contract pragma. For Foundry projects, use the foundry compile framework so Foundry manages the compiler version.
Use Echidna for stateful, multi-transaction sequence testing of system invariants. Slither is faster for static checks, and Foundry fuzz tests single functions, but neither explores stateful call sequences like Echidna.
pashovGenerate and run fuzz tests for Solidity smart contracts using Echidna and Medusa.
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YukiIto1999Analyze Solidity smart contracts for vulnerabilities using Slither and Mythril.
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