zen-devtools-mcp: Instructions file for Codex

AGENTS.md

zen-devtools-mcp AGENTS.md is an instructions file for Codex, OpenCode from simon-ami/zen-devtools-mcp. It costs 289 tokens per session, scanned A, original, from a forked repository, no licence file.

Project instructions for an unofficial MCP server that lets AI assistants inspect and control Zen Browser through browser automation interfaces. Zen Browser is a web browser, and MCP is a way for tools to expose actions to an assistant.

In plain words
What is it for?
Use them when developing or modifying the Zen DevTools MCP server, especially code that communicates with Zen Browser through WebDriver BiDi.
Why use it?
They explain how the project should be worked on and how browser inspection or control is intended to function.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is simon-ami/zen-devtools-mcp's own configuration. It tells Codex and OpenCode how to work on zen-devtools-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything zen-devtools-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to simon-ami/zen-devtools-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/simon-ami/zen-devtools-mcp/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/simon-ami/zen-devtools-mcp

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 zen-devtools-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/simon-ami/zen-devtools-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/simon-ami/zen-devtools-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/simon-ami/zen-devtools-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/simon-ami/zen-devtools-mcp/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for zen-devtools-mcp AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/simon-ami/zen-devtools-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/simon-ami/zen-devtools-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 289 This file is loaded in full into every session.
When invoked 289 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin fork From a forked repository.
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 5.1 $0.00289 $0.00289
Opus 5.5 $0.00116 $0.00116
Sonnet 5.5 $0.00058 $0.00058
Haiku 4.5 $0.00029 $0.00029

Measured 2mo ago against content hash f23ec75cbc82, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

zen-devtools-mcp AGENTS.md scanned grade A with 0 findings 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 2mo 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 13 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 2mo ago First seen · 13 lines · 289 tokens per session scan A f23ec75cbc82

Subscribe to this mod's changes

zen-devtools-mcp AGENTS.md is an instructions file published in the GitHub repository simon-ami/zen-devtools-mcp (3 stars, last pushed 3mo ago), with no licence file. It adds 289 tokens to every session, about $0.0012 per session on Opus 5.5. A static security scan graded it A with 0 findings. It comes from a forked repository.

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