What do I need before running Hal?
You need a repository, a clear product requirement or PRD, and access to a supported AI coding engine such as Codex, Claude Code, or Pi.
Docs
Install Hal, initialize the repo workflow, turn requirements into stories, run a bounded agent loop, and inspect the result before merging.
Use the current website install command, then open the GitHub README if you need repository-specific setup details before running it in a project.
brew tap j-yw/tap && brew install --cask hal Read the install guide for verification steps, engine prerequisites, and a safe repository setup.
Your first Hal loop should be boring on purpose. Pick a bounded change with clear acceptance criteria so you can inspect the plan, the changed files, and the final state in one sitting.
hal init
hal plan "add a small settings page with one saved preference"
hal convert
hal validate
hal run hal init creates the local workflow structure for a repo.hal plan turns product intent into a PRD or structured requirements before the agent touches code.hal convert turns markdown requirements into runtime state.hal validate checks that stories are specific enough for the loop.hal run executes implementation iterations with the configured agent engine.Before merging agent output, inspect the changed files, commits, reports, tests, and unresolved acceptance criteria. Hal structures the loop; the developer still owns acceptance.
Use the review-before-merge checklist before accepting any generated code.
Move from installation to a bounded first loop and a human-owned merge decision.
Short answers before you put an agent loop in motion.
You need a repository, a clear product requirement or PRD, and access to a supported AI coding engine such as Codex, Claude Code, or Pi.
Start with a small, low-risk requirement that has clear acceptance criteria and can be reviewed in one sitting.
No. Hal is designed to leave reviewable state, commits, reports, and archives so a developer can inspect the work before merging.
The Hal source is available on GitHub at https://github.com/ReScienceLab/hal.