Boffin

Boffin (npm: boffinit) is a staff-engineer control layer for AI coding agents: it feeds the agent the architectural constraints for the exact file it is editing and makes it verify the result -- DuckDB case study: a guided refactor landed at +17 / -17 lines with 2,104 assertions passing.

You ask for a 15-line fix; the agent comes back with a 500-line renovation. Boffin gives the agent the architectural constraints that apply to the file it is about to touch, then makes it verify the result.

It is not another AGENTS.md and not a prompt pack. Those formats usually ship one static instructions block for the whole repository; Boffin routes only the constraints relevant to the current edit. Powered by ParselFire Core.

npx boffinit cursor

What Boffin is not

• Not a static repo-wide rules file (AGENTS.md-style one block for everything)
• Not a prompt pack or system-prompt trick
• Not a linter or CI gate -- it acts before and after the edit
• Not a speed tool -- the frame is review-safety

What Boffin does

• Selects the constraints relevant to the edit in front of the agent
• Requires verification proportional to the change
• Ships for Cursor, Claude Code, Codex, and OpenCode from one npm package
• Delivers signed portable packs powered by ParselFire Core

How it differs (honest comparison)

	Static rules file (AGENTS.md)	Boffin
Delivery	Usually one static block for the whole repo	Constraints routed to the current edit
Verification	None required by the format	Required, proportional to the change
Evidence	Usually none	Recorded case studies with numbers

Proof, not promises

The public case studies record these guided refactors on real open-source code:

• DuckDB: +17 / -17; 2,104 assertions across 8 test files passed; distinct continuation and recovery paths were preserved.
• FastAPI: +16 / -33; 49 tests passed; no public API change.
• LangChain: the sync/async boundary was preserved; 4 tests passed.

These are reproducible case studies, not a controlled A/B benchmark.

Install

Boffin requires Node.js 18 or newer.

Cursor

Run from your project:

npx boffinit cursor

Claude Code

Run these inside Claude Code:

/plugin marketplace add MicSm/boffin
/plugin install boffin@boffin

Codex

Run these from a terminal:

codex plugin marketplace add MicSm/boffin
codex plugin add boffin@boffin

Codex does not trust plugin hooks automatically. Run /hooks once inside Codex to review and trust Boffin's hooks; until then the plugin's skills work but the automatic per-session activation stays off.

OpenCode

Run from your project:

npx boffinit opencode

Then open the project in OpenCode. Always-on guidance lands via opencode.json -> .boffin/AGENTS.md. On demand: /boffin, /boffin-review, or the boffin / boffin-review skills.

Install details, commands, and troubleshooting: OpenCode delivery.

Want the machinery? Read how ParselFire Core works.

What Boffin is fussy about