What is real-browser-mcp AGENTS.md?

Operational instructions for the real-browser-mcp project, which connects an MCP server to a local broker, native host, and Chrome extension. They describe the current setup and how its browser tools are expected to work.

Use them when developing, reviewing, troubleshooting, or validating the real-browser-mcp server, broker, native host, extension, screenshots, downloads, and browser extraction tools.

They give an agent the project context needed to use and validate the browser bridge correctly, including its message format and connection status.

How ton-to-ton/real-browser-mcp configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to ton-to-ton/real-browser-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/ton-to-ton/real-browser-mcp/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/ton-to-ton/real-browser-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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/ton-to-ton/real-browser-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/ton-to-ton/real-browser-mcp/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/ton-to-ton/real-browser-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/ton-to-ton/real-browser-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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/ton-to-ton/real-browser-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/ton-to-ton/real-browser-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 3,154 This file is loaded in full into every session.

When invoked 3,154 The same file — it is already loaded in full.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.03154	$0.03154
Opus 5	$0.01577	$0.01577
Sonnet 5	$0.00631	$0.00631
Haiku 4.5	$0.00315	$0.00315

Measured 9d ago against content hash 010311fe8abe, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

real-browser-mcp AGENTS.md scanned grade A 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 9d 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

p = subprocess.Popen(

AGENTS.md · 150 lines

How it starts

The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md - Real Browser MCP

Overview

Real Browser MCP is an MCP-facing fork of the upstream browser bridge.

Architecture:

MCP Server <-> Local Broker <-> Native Host <-> Chrome Extension

Core files:

bin/mcp-server.js: stdio MCP entrypoint for MCP clients
bin/cli.js: installer, status, tool runner, and MCP launch wrapper
bin/broker.cjs: local broker with per-session tab ownership
bin/native-host.cjs: Chrome Native Messaging host
extension/background.js: browser-side tool execution
dist/plugin.js: bundled tool layer reused from the upstream implementation

Current State

MCP startup works with Codex CLI 0.114.0.
The MCP server accepts Codex's JSONL-style initialize/tools/* messages.
The MCP server also serves text resources/* and prompt runbooks over the same stdio transport.
Native host, broker, and Chrome extension have been verified end-to-end up to browser_status reporting hostConnected: true.
browser_screenshot exposes fullPage.
Download flows are verified for direct URL, selector-triggered, wait=true, and competing-download association cases.
browser_extract and browser_task are implemented in the bundled tool layer and covered by self-test.
rpa_run, rpa_runs_list, rpa_run_get, rpa_run_cancel, and rpa_templates_list now expose a native-first browser RPA layer above browser_task.
browser_route now supports both block and mock actions on the profile backend.
Both backends now expose browser_context_*, browser_trace_*, browser_har_*, and browser_video_*.
On the native backend, isolated contexts are backed by split incognito windows and require Chrome's "Allow in Incognito" toggle.
Backend selection now supports native, agent, and auto, with native as the default and auto available only when explicitly requested.
MCP exposes resources/list, resources/read, resources/templates/list, prompts/list, and prompts/get.
The fixed unpacked extension ID derived from the manifest key is hcghacpnkedkkbelmhapbobekbdfmppi.
The broker's ensureSessionTab now receives the caller's preferredHostId so that auto-tab creation works when multiple browser hosts (regular + incognito) are connected.

Read the full file on GitHub · 150 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.

9d ago First seen · 150 lines · 3,154 tokens per session scan A 010311fe8abe

Subscribe to this mod's changes

real-browser-mcp AGENTS.md is an instructions file published in the GitHub repository ton-to-ton/real-browser-mcp (0 stars, last pushed 2mo ago), licensed MIT. It adds 3,154 tokens to every session, about $0.0158 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

next.js AGENTS.md

AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,153 tokens

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

real-browser-mcp: Instructions file for Codex