Run agents against gates that can refuse
Antigravity,Claude, Codex and Grok, behind one task model.
About us
Bringing trust to agentic coding
Cotterpin exists to bring trust to agentic coding. A cotter pin is the small part whose only job is to stop something falling apart while it moves. Cotterpin does that for AI coding agents: a task counts as done only when evidence says so — not when the agent says so.
Why it exists
Agents are fast. Trusting them shouldn't be a leap of faith.
AI agents now write a real share of the world's code. They're fast, tireless and genuinely useful — and they have a habit no linter catches: they run the tests, see them pass, and report work as delivered that was never wired up.
Lint, types and unit tests are free and everywhere. What's missing is the layer that asks “is it actually done?” and won't take the agent's word for it. That's Cotterpin.
Catch what linters can't
Unwired features, tests that only agree with themselves, fixes that break under a race.
Prove it
Every verdict is backed by a receipt bound to exactly what it checked. Destructive agent actions wait for a person's approval, signed by a key no agent can read.
Keep your code local
Cotterpin never receives your source, diffs or prompts. Only your chosen model provider sees your code, under your own account.
The founder
From fifteen years of fixing things at 2am.
Founder · Senior DevOps engineer
I've spent fifteen years as a DevOps engineer — building pipelines, hardening systems, chasing down the bug that only appears in production, and being the person who gets the call when something falls over. I'm all-in on agentic coding: it's the biggest change to how software gets made that I've seen in my career.
But using agents every day, I kept hitting the same wall. The agent would say “done”. The tests were green. And the feature didn't work. I was spending my evenings re-checking work that was supposed to save me time.
So I took everything those fifteen years taught me — about coding, troubleshooting, security and fixing what's actually broken — and turned it into gates. Every gate in Cotterpin exists because a real failure got past everything else. Cotterpin is how I made agentic coding something I can trust. I built it to take that pain away for you too.
What we believe
Four principles we won't trade away.
Evidence over claims
“Done” means proven. That applies to the agents we check — and to us.
Your code is yours
Local-first, always. We have no cloud that sees your source.
Honest numbers
We report what we measured, and label anything estimated as an estimate.
You stay in charge
Cotterpin advises, blocks and proves. You decide what lands.
Questions, ideas, or a war story about an agent?
We'd genuinely like to hear it.