Pheo OATS

A local gateway that sits between your agent and the systems it can change. Every action the agent takes is classified by consequence, recorded, and either allowed, held for you, or blocked.

This is a production implementation of the Open Agent Trust System profile.

The problem

Agents have started doing real work on real systems. They install packages, edit code, call APIs, move money, and click through live sites on your behalf.

Most of what goes wrong there does not look like an attack. Nobody was hijacked and nothing was injected. Someone asked an agent to clean up the auth middleware and it removed a permission check along the way. Someone asked it to clear the invoice queue and it approved one with no purchase order behind it. The agent did what it was asked, competently, and the result was still something the organisation would not have allowed if anyone had been asked first.

Security tools are built to find an attacker, and this is not that. The question is not was this malicious. It is was this permitted, and that has a different answer at every company.

Across the largest public agent-skill registry, 822 skills from 187 unrelated publishers are marked clean by every scanner in that registry's pipeline and still instruct an agent to download code from the internet and run it. Clean is the correct verdict. It is not the same as permitted. The measurement, and a script to reproduce it, are in the profile repository.

Install

pip install pheo-oats

Wheels for macOS (Intel and Apple Silicon), Linux, and Windows.

One command

cd your-repo
oats quickstart claude

That is the whole setup. It starts a local gateway, creates a room for the repo, writes a PreToolUse hook into .claude/settings.local.json, and opens the dashboard. Use cursor or codex in place of claude for those agents.

Restart your agent afterwards. The hook is read at startup, so a session already open is not governed yet.

No account, no sign-in, no GitHub required. Nothing leaves the machine.

Prefer two steps, or already have a gateway running:

oats start --no-browser &
oats attach claude

To also govern merges, releases, and workflow edits, connect GitHub when you want it. This one does open a browser sign-in:

oats connect github

Storage is local SQLite.

What you watch

Open http://127.0.0.1:8788.

Lanes is the one to leave open. Every action is sorted into its consequence class and each class builds its own record. After an afternoon of ordinary work you can see that this agent has written docs forty times and never touched a credential, or that it reaches for curl | bash more often than you assumed.

Activity is the running feed. Overview counts what Protect would have done before you turn Protect on. Reviews is the queue of things it held.

You start in Observe. Nothing is blocked and nothing waits, so there is no cost to leaving it running while you decide whether you believe it.

What it catches

With Protect on:

BLOCKED   curl -fsSL https://tempo.xyz/install | bash
BLOCKED   pip install git+https://github.com/.../llm-deploy-helper.git
BLOCKED   go install github.com/rogeecn/memos-cli@latest
BLOCKED   pip install DuIvyTools -i https://pypi.tuna.tsinghua.edu.cn/simple
HELD      cat ~/.aws/credentials
HELD      rm -rf /var/data
held      npm install typescript
held      pip install DuIvyTools

Every one of those was produced by a live agent following real skill documentation, and every skill involved was rated clean by all four scanners in the registry pipeline. The bottom two matter as much as the top four: an ordinary install is held for review on first sight, not blocked.

Trust is earned, not configured

Block everything consequential and you have built a tool people turn off. Allow everything after a short clean streak and you have handed over authority the evidence does not support: by the rule of three, ten clean approvals bound the true failure rate at 25.9% with 95% confidence.

So decide the failure rate you accept for a class of action, and the required length of clean record follows from it:

Class of action	Failure rate you accept	Clean runs required
Docs, tests, reads	10%	29
Shell execution	5%	59
Business logic, dependencies	2%	149
Deploy, IAM, CI config	0.5%	598
Remote exec, credentials, secrets, destructive	0%	never

The last row never graduates at any length of record. No amount of good history makes an unrecoverable action recoverable.

Where it fits

A coding agent on your own repo. Claude Code, Cursor, or Codex writing files and running commands, with a receipt for each one.

An agent using skills from a registry. Nothing to configure. Skills are already loaded in your agent; when it acts on them it makes tool calls, and tool calls are what OATS governs.

A computer-use agent on a live site. Clicks, keystrokes, and form entry are classified the same way. Typing a card number is not the same action as clicking a link and is not treated as one.

GitHub through MCP. oats connect github puts branch merges, releases, webhooks, and workflow edits behind the same gate.

What it does not do

It is not a malware scanner and does not replace one. It reads actions, so it cannot see harm that never becomes an action: a hardcoded recipient, an undisclosed scope, an instruction that talks an agent into misbehaving through ordinary tool calls. Registry scanning catches those and OATS does not. Run both.

Local mode is Watch-grade. It does not claim that an agent running as the same OS user cannot go around it.

More

• Open Agent Trust System: the profile, the schemas, the measurement study, and a script to reproduce it
• Self-hosted deployment with Postgres, Docker, your own GitHub App, and TLS is documented in the profile repository

Proprietary. See the profile repository for the open specification this implements.