Halfcycle

Halfcycle is a method for building software with coding agents, delivered as a tool that runs inside your own Claude Code. It supplies the roles around the coding agents (product owner, architect, planner and reviewer) and checks when a phase isn't actually finished. The site says it runs on your own Claude seats, leaves nothing behind in your repo, and is free for solo developers.

What It Is

Halfcycle is a planning and review layer for agent-driven development. You state what you want to build and it guides you through the steps, reading your project to work out how far along you are and telling you the next step. Install is a single command, npx halfcycle.

The Four Roles

• Product owner: asks one question at a time with a suggested answer and reason, records rejected options, and will not pass on a spec with placeholders or unanswered questions.
• Architect: works out how pieces fit, draws a diagram, and extracts rules the system must never break, with short references so later work cites them.
• Planner: cuts work into shippable pieces, splits oversized ones, and labels guesses as guesses.
• Reviewer: reads the plan back before detailed design starts, running away from your machine so it cannot mark its own work. Claims about existing code must point at a real line in a real file.

A Growing Checklist of Failure Modes

The site describes a list of recurring failures, such as tests that exercise stand-ins rather than real paths, mismatched names between two halves of a system, and permission rules enforced in only one place. Each became a check at the planning stage; the vendor says code-level checks are planned for the next release. Halfcycle also states a bar for "finished": verified by a real signed-in user on the deployed product, with no silent failures. It says it does not measure performance and does not replace dependency scanning, threat modelling or penetration testing.

Ways to Use It

The site lists three options: Halfcycle itself (available now), Halfcycle Studio, a guided platform that builds the product (coming soon), and Consulting, where the firm teaches your team the method (available now). The company is backed by nuCode Tech Capital.