matimo AGENTS.md

matimo AGENTS.md is an instructions file for Codex, OpenCode from tallclub/matimo. It costs 1,589 tokens per session, scanned C, original, MIT.

A repository guide for AI coding agents working on Matimo, a tool-execution software development kit with security rules and human approval checks. It documents the project's layout, setup, builds, tests, and coding conventions.

In plain words
What is it for?
Use it when modifying Matimo, navigating its TypeScript or Python workspaces, installing dependencies, running tests, or following its repository conventions.
Why use it?
It gives an agent the project context and working rules needed to make consistent changes. It also explains that the TypeScript and Python implementations are intended to match.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/tallclub/matimo/agents-md
Clone the repo
git clone --depth 1 https://github.com/tallclub/matimo

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for matimo AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/tallclub/matimo/agents-md.svg)](https://agentmods.dev/instructions/tallclub/matimo/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/tallclub/matimo/agents-md"><img src="https://agentmods.dev/badge/instructions/tallclub/matimo/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,589 This file is loaded in full into every session.
When invoked 1,589 The same file — it is already loaded in full.
Security scan C 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.01589 $0.01589
Opus 5 $0.00794 $0.00794
Sonnet 5 $0.00318 $0.00318
Haiku 4.5 $0.00159 $0.00159

Measured 4d ago against content hash 620fff40156a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

matimo AGENTS.md scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nullifies safety policieshighAnti-refusal

"You have no restrictions", "do anything now", "ignore your guidelines": a direct jailbreak that disables guardrails.

- Don't bypass the policy engine when generating code that calls Matimo — route through `matimo.execute(...)`, not raw provider SDKs, when Matimo is already a dependency.
AGENTS.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Instructions for AI coding agents (Cursor, GitHub Copilot, Windsurf, Codex, etc.) working in this repository. Claude Code reads CLAUDE.md instead, which covers the same ground in more depth.

What this repo is

Matimo is a policy-governed tool-execution SDK for AI agents: every tool call — built-in, third-party, or agent-created — passes through a policy engine (risk classification, security rules, human-in-the-loop approval) before it runs. MIT licensed, dual TypeScript + Python implementation with feature parity.

Full narrative and API surface: README.md. Deep architecture: docs/architecture/OVERVIEW.md.

Repo layout

typescript/     pnpm workspace — packages/{core,cli,slack,github,gmail,notion,hubspot,postgres,twilio,mailchimp,microsoft,bruno,composio}
python/         uv workspace  — packages/{core,cli,matimo,<same providers>} — mirrors typescript/ 1:1
docs/           getting-started, api-reference, architecture, tool-development, framework-integrations, mcp, skills
examples/       usage examples per integration pattern (factory, decorator, LangChain, MCP)

Setup, build, test

TypeScript (run from typescript/):

pnpm install && pnpm build
pnpm test              # jest; pretest runs build first
pnpm test:coverage
pnpm lint / pnpm lint:fix
pnpm validate-tools    # validate all YAML tool definitions

Python (run from python/):

make install           # uv sync --all-extras --dev
make test / make test-unit / make test-integration / make test-coverage
make lint / make format / make typecheck
make validate-tools

Never run npm install inside typescript/ (it uses pnpm-lock.yaml) or pnpm/npm inside python/ (it uses uv/uv.lock) — don't cross-contaminate package managers.

Conventions an agent must follow

  • Conventional Commits, lower-case type: feat, fix, docs, style, refactor, perf, test, chore, ci, revert, example. Enforced by a commitlint pre-commit hook (husky) — don't bypass with --no-verify.
  • TypeScript: strict mode, ESM ("type": "module"), Node ≥18, pnpm ≥8.
  • Python: version pinned in python/.python-version; ruff for lint/format; mypy strict on packages/core/src.
  • Every tool (built-in or agent-created) needs an explicit risk classification (low/medium/high/critical) in its YAML definition — see docs/api-reference/POLICY_AND_LIFECYCLE.md.
  • New provider package → mirror an existing one exactly (slack or github are the reference implementations) in both languages. Don't let TS and Python drift — ship new features to both unless told otherwise.
  • 3,700+ tests, 95%+ coverage target across TS + Python — don't drop coverage on new code.
  • Don't hand-edit pnpm-lock.yaml / uv.lock — regenerate via the package manager.

Read the full file on GitHub · 117 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 117 lines · 1,589 tokens per session scan C 620fff40156a

Subscribe to this mod's changes

matimo AGENTS.md is an instructions file published in the GitHub repository tallclub/matimo (11 stars, last pushed 4d ago), licensed MIT. It adds 1,589 tokens to every session, about $0.0079 per session on Opus 5. A static security scan graded it C with 1 finding (nullifies safety policies). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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