NomicFoundation

Add or modify a "util" in the Hardhat repo — a small, project-independent command exposed both as a built-in Hardhat task (`hardhat utils <ns> <cmd>`) and through the standalone `hhu <ns> <cmd>` binary, defined once in the `hhu` built-in plugin. Use when…

Analyzes the Hardhat regression benchmark history (the hardhat-benchmark-results repo's data.js) and recommends how many times each benchmark should run. It reads every commit's individual run times, computes each benchmark's per-commit coefficient of…

Use when working with Hardhat 3 projects — writing or modifying Solidity tests, TypeScript tests, or any code touching hardhat.config.ts, the `hardhat` import, or `network.create()`. Covers test-layer choice, forge-std cheatcodes, the network connection API,…

Use alongside the `hardhat` skill when the project depends on `@nomicfoundation/hardhat-toolbox-mocha-ethers`. Covers the ethers helpers exposed on `network.create()`, contract interaction (`ethers.deployContract`, calling functions, `connect`),…

Use alongside the `hardhat` skill when the project depends on `@nomicfoundation/hardhat-toolbox-viem`. Covers the viem clients exposed on `network.create()`, contract interaction (`viem.deployContract`, `read`, `write`, `getContractAt`), and `viem.assertions`…

Set up a local Verdaccio environment to test EDR + Hardhat 3 + a third-party repo (e.g. openzeppelin-contracts). Builds EDR with a chosen Rust profile, publishes EDR and Hardhat packages to a local Verdaccio registry, and installs them in the target repo. Use…

Update REVM and related crate dependencies (revm, revm-primitives, revm-interpreter, revm-precompile, revm-handler, revm-context, revm-context-interface, revm-database-interface, revm-state, revm-bytecode, revm-inspector, op-revm) to a specific release…

Systematically migrate a Hardhat V2 project to Hardhat V3, covering core changes (ESM, declarative config, hooks system, network connections) and the full plugin ecosystem (hardhat-deploy, hardhat-verify, @openzeppelin/hardhat-upgrades, and others), coverage…

Migrate a Solidity project from Foundry to Hardhat 3. Maps `foundry.toml` to `hardhat.config.ts`, converts dependencies and imports, gets compilation and Solidity tests passing, and produces a migration report with feature-parity gaps and a cleanup checklist.

Address reviewer feedback on an open pull request — fetch unresolved review threads, reply within each thread, and commit requested changes. Use whenever responding to PR review comments, addressing review feedback, or working through reviewer threads on the…