Justus: Justus moved page Echidna Tricks to Echidna tricks: spelling

2026-01-30T04:55:09Z

Justus moved page Echidna Tricks to Echidna tricks: spelling

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	Compared to code scanners and formal methods, Echidna is good at finding transactions that can trigger ''unintended'' behavior in smart contracts. Since Echidna is a [https://en.wikipedia.org/wiki/Fuzzing#Aware_of_program_structure coverage-guided fuzzer], it’s also good at finding ways to hit the entire code surface of a smart contract.		Compared to code scanners and formal methods, Echidna is good at finding transactions that can trigger ''unintended'' behavior in smart contracts. Since Echidna is a [https://en.wikipedia.org/wiki/Fuzzing#Aware_of_program_structure coverage-guided fuzzer], it’s also good at finding ways to hit the entire code surface of a smart contract.

	To test a smart contract with Echidna, you have to define a testing interface that it can to interact with your contract under test. This interfaces contains either [https://secure-contracts.com/program-analysis/echidna/basic/assertion-checking.html assertions] or [https://secure-contracts.com/program-analysis/echidna/introduction/how-to-test-a-property.html properties]. You can select which kind of test Echidna should perform using the command line flag <code>--test-mode</code>.		To test a smart contract with Echidna, you have to define a testing interface that Echidna can use to interact with your contract under test. This interfaces contains either [https://secure-contracts.com/program-analysis/echidna/basic/assertion-checking.html assertions] or [https://secure-contracts.com/program-analysis/echidna/introduction/how-to-test-a-property.html properties]. You can select which kind of test Echidna should perform using the command line flag <code>--test-mode</code>.

	<span id="configuration-options"></span>		<span id="configuration-options"></span>

Justus: Created page with "Here are some useful tricks for getting the best out of [https://github.com/crytic/echidna Echidna]. Echidna is a fuzzing tool for smart contracts written in [https://docs.soliditylang.org/en/v0.8.30/ Solidity]. Solidity smart contracts primarily work on the [https://ethereum.org/en/ Ethereum] blockchain. Some smart contracts are responsible for managing large amounts of cryptocurrency. With Echidna you can evaluate the security of smart contracts. Compared to code sca..."

2026-01-30T04:30:38Z

Created page with "Here are some useful tricks for getting the best out of [https://github.com/crytic/echidna Echidna]. Echidna is a fuzzing tool for smart contracts written in [https://docs.soliditylang.org/en/v0.8.30/ Solidity]. Solidity smart contracts primarily work on the [https://ethereum.org/en/ Ethereum] blockchain. Some smart contracts are responsible for managing large amounts of cryptocurrency. With Echidna you can evaluate the security of smart contracts. Compared to code sca..."

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Here are some useful tricks for getting the best out of [https://github.com/crytic/echidna Echidna].

Echidna is a fuzzing tool for smart contracts written in [https://docs.soliditylang.org/en/v0.8.30/ Solidity]. Solidity smart contracts primarily work on the [https://ethereum.org/en/ Ethereum] blockchain. Some smart contracts are responsible for managing large amounts of cryptocurrency. With Echidna you can evaluate the security of smart contracts.

Compared to code scanners and formal methods, Echidna is good at finding transactions that can trigger ''unintended'' behavior in smart contracts. Since Echidna is a [https://en.wikipedia.org/wiki/Fuzzing#Aware_of_program_structure coverage-guided fuzzer], it’s also good at finding ways to hit the entire code surface of a smart contract.

To test a smart contract with Echidna, you have to define a testing interface that it can to interact with your contract under test. This interfaces contains either [https://secure-contracts.com/program-analysis/echidna/basic/assertion-checking.html assertions] or [https://secure-contracts.com/program-analysis/echidna/introduction/how-to-test-a-property.html properties]. You can select which kind of test Echidna should perform using the command line flag <code>--test-mode</code>.

<span id="configuration-options"></span>
= Configuration options =

Echidna has a lot of [https://secure-contracts.com/program-analysis/echidna/configuration.html configuration options]. Here are some options that I recently used when going through the [https://github.com/crytic/building-secure-contracts/tree/master/program-analysis/echidna Building Secure Contracts Echidna tutorial]:

* <code>testMode</code>: When working through the tutorials, I’ve only ever used <code>property</code> or <code>assertion</code>.
* <code>deployer</code> and <code>sender</code>: Set these to the same value to ensure that the same account makes all transactions. <code>deployer</code> takes a single address, <code>sender</code> accepts a list of strings.
* <code>cryticArgs</code>: Set <code>["--solc-remaps", "prefix=target"]</code> if you have dependencies somewhere else. Example: <code>@openzeppelin=../node_modules/@openzeppelin</code> if your Node.js modules are in the parent directory.
* <code>balanceContract</code>: Give this some Ether so that the contract under test can deploy and fund other contracts.
* <code>balanceAddr</code>: Give <code>deployer</code> and <code>sender</code> Ether using this setting.
* <code>shrinkLimit</code>: Shrinking stops too early? Set the limit to a higher number than the default <code>5000</code>.
* <code>testLimit</code>: Tests stop too early? Add more iterations using this setting.

Here’s how it can look like when you combine some of these settings:

<syntaxhighlight lang="yaml"># Give both the Test contract, as well as the sender 100 Wei
balanceContract: 100
balanceAddr: 100
# Run in assertion mode
testMode: assertion
# Let Echidna interact with the public interfaces of all contracts
allContracts: true
# You can leave out leading zeros in addresses
# This address deploys your contract
deployer: "0x30000"
# These addresses interact with your contracts
sender:
- "0x10000"
- "0x20000"
- "0x30000"
# Don't let Echidna send Ether to the test contract
filterBlackList: true
filterFunctions:
- "Test.fallback()"
cryticArgs:
- "--solc-remaps"
- "@openzeppelin=../node_modules/@openzeppelin"
# Run 20 workers in parallel. Adjust to the number of CPU cores
workers: 20
# Attempt to shrink an interesting case 10,000 times
shrinkLimit: 10000
# Run 1 million tests
testLimit: 1000000</syntaxhighlight>
When you create your configuration file, you can tell Echidna to use it with the <code>--config</code> command line flag. Here’s how to run Echidna using the configuration file <code>echidna.yaml</code>.

<syntaxhighlight lang="bash">echidna --config echidna.yaml --contract Test test.sol</syntaxhighlight>
This assumes your test contract is called <code>Test</code> and is in a file called <code>test.sol</code>:

<span id="resources"></span>
= Resources =

* [https://github.com/crytic/building-secure-contracts/tree/master Building Secure Contracts]
* [https://secure-contracts.com/program-analysis/echidna/index.html Echidna tutorial from secure-contracts.com]
* [https://secure-contracts.com/program-analysis/echidna/configuration.html Echidna Configuration options]
* [https://ethernaut.openzeppelin.com/ Ethernaut challenge]

Echidna tricks - Revision history

Justus: Justus moved page Echidna Tricks to Echidna tricks: spelling

Justus: fix grammar