# Reins Engineering

Generation can be probabilistic. Verification must be deterministic.

## Concept

- [Reins Engineering — AI with Reins](https://www.parkjunwoo.com/opinion/reins-engineering.md) — Harness is a fence. Reins steer.
- [Why Coding Agents Work and Why They Break](https://www.parkjunwoo.com/opinion/why-agents-work-and-break.md) — The topology changed, not the model.
- [Feedback Topology Over Model IQ](https://www.parkjunwoo.com/opinion/feedback-topology.md) — The same model stalls at 40 or completes all 527.
- [AI Sycophancy Bias Is a Business Feature](https://www.parkjunwoo.com/opinion/sycophancy-is-a-feature.md) — Sycophancy is not a bug. It is RLHF's mathematical inevitability.
- [Agent Operable Codebase](https://www.parkjunwoo.com/opinion/agent-operable-codebase.md) — The office must be turned into a factory.
- [Building Agent-Operable Systems](https://www.parkjunwoo.com/opinion/building-agent-operable-systems.md) — Locked legacy becomes reachable. Freeze bugs first, then transform.

## Pattern

- [Ratchet Pattern — How to Make an Agent Finish the Job](https://www.parkjunwoo.com/tech/ratchet-pattern.md) — A mechanical lock that prevents backward drift. Ratchet code never allows regression below a passed verification level.
- [Ratchet Code That Exploits IFEval](https://www.parkjunwoo.com/tech/ifeval-ratchet.md) — Sycophancy bias as an asset, not a bug.
- [Hurl Stops Vibe Coding Drift](https://www.parkjunwoo.com/tech/hurl-vibe-coding-drift.md) — Declare API contracts in plain text. Lock with a ratchet.

## Toolchain

- [yongol — The Keel of AI-Coded SaaS](https://www.parkjunwoo.com/tech/yongol.md) — 10 declarative specs, one CLI. Context compression ~10x.
- [filefunc — One File, One Concept](https://www.parkjunwoo.com/tech/filefunc.md) — The navigation unit for an AI agent is the file.
- [huma — A Ratchet That Never Skips an Endpoint](https://www.parkjunwoo.com/tech/huma.md) — scan, next, write, verify. Four commands, zero config.
- [codistill — Squeeze SSOT Out of Existing Code](https://www.parkjunwoo.com/tech/codistill.md) — Not foundation work. Seismic retrofitting.
- [tsma — Regression Defense Line for Legacy Code](https://www.parkjunwoo.com/tech/tsma.md) — One command builds a defense line around legacy code.
- [Feature Chain — Tracing the full stack with one operationId](https://www.parkjunwoo.com/tech/feature-chain.md) — One operationId extracts the entire scope.

## Foundation

- [toulmin — A Rule Engine That Computes Contracts](https://www.parkjunwoo.com/tech/toulmin.md) — Rules are functions, verdicts via h-Categoriser.
- [SSaC — Service Sequences as Code](https://www.parkjunwoo.com/tech/ssac.md) — Declare only what. The codegen fills in how.
- [whyso — What git blame doesn't tell you](https://www.parkjunwoo.com/tech/whyso.md) — git blame tells who. whyso tells why.