agentmods.dev

mcp-browser-bridge: Instructions file for Claude Code

CLAUDE.md

mcp-browser-bridge CLAUDE.md is an instructions file for Claude Code from adbarc92/mcp-browser-bridge. It costs 1,117 tokens per session, scanned A, original, MIT.

Project instructions for working on the mcp-browser-bridge repository, including its build commands, tests, architecture, server code, and browser extension.

In plain words
What is it for?
Use them when developing the TypeScript MCP server or its plain-JavaScript browser extension, running tests, or starting the development build.
Why use it?
They give an agent the repository-specific context needed to build and test the project consistently.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md; mentions Claude Code.

This is adbarc92/mcp-browser-bridge's own configuration. It tells Claude Code how to work on mcp-browser-bridge 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 mcp-browser-bridge configures →

not rated 1 7d ago A scan 1,117 tokens original MIT
View the source file adbarc92/mcp-browser-bridge npmjs.com
Reuse

Borrowing it

Nothing to install: this file belongs to adbarc92/mcp-browser-bridge. 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/adbarc92/mcp-browser-bridge/master/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/adbarc92/mcp-browser-bridge

Made for: Claude Code.

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 mcp-browser-bridge CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/adbarc92/mcp-browser-bridge/claude-md.svg)](https://agentmods.dev/instructions/adbarc92/mcp-browser-bridge/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/adbarc92/mcp-browser-bridge/claude-md"><img src="https://agentmods.dev/badge/instructions/adbarc92/mcp-browser-bridge/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,117 This file is loaded in full into every session.
When invoked 1,117 The same file — it is already loaded in full.
Security scan A 0 findings. 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 5.1 $0.01117 $0.01117
Opus 5 $0.00558 $0.00558
Sonnet 5 $0.00223 $0.00223
Haiku 4.5 $0.00112 $0.00112

Measured 5d ago against content hash 1631bfb7e103, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

mcp-browser-bridge CLAUDE.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 5d 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.

CLAUDE.md · 82 lines

How it starts

The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Build & Dev Commands

npm install              # Install dependencies
npm run build            # Compile TypeScript → dist/
npm run dev              # TypeScript watch mode for development
npm test                 # Run test suite (vitest)
npm run test:watch       # Run tests in watch mode
npm link                 # Register 'mcp-browser-bridge' as a global CLI command

Tests use Vitest and live alongside source files (src/**/*.test.ts). They are excluded from the TypeScript build via tsconfig.json. The WebSocket server tests use port 17483 to avoid conflicts with a running server.

The extension uses plain JavaScript (no build step). No linter is configured.

Architecture

This is a two-way bridge between MCP clients and Chromium browsers:

MCP Client ←(MCP stdio)→ MCP Server ←(WebSocket localhost:7483)→ Browser Extension ←(Chrome APIs)→ Browser

The extension is plain JS, not a workspace.

Server (src/)

TypeScript, ESM ("type": "module"), targets ES2022.

  • index.ts — Entry point with shebang for global CLI. Creates WebSocket server, MCP server, wires events, handles graceful shutdown.
  • mcp-server.ts — Defines 11 MCP tools (browser_status, browser_navigate, browser_screenshot, browser_evaluate, browser_click, browser_fill, browser_get_content, browser_get_tabs, browser_get_console, browser_wait_for, browser_send_message). Uses Zod for parameter validation. Registers prompts via prompts.ts.
  • prompts.ts — Registers MCP prompts (browse, qa-runner) that ship browsing and QA workflow instructions to any connected MCP client.
  • ws-server.ts — WebSocket server on 127.0.0.1:7483. Single-client model (replaces stale connections). Origin verification accepts any -extension:// protocol. JSON-RPC 2.0 request/response with UUID tracking. Keepalive ping every 20s.
  • protocol.ts — JSON-RPC 2.0 types, method names, event names, error codes (-32000 to -32003 for domain errors), timeout constants.
  • utils/logger.ts — Stderr logger controlled by BRIDGE_LOG_LEVEL env var.
  • utils/pending-requests.ts — UUID-based request tracking with timeout auto-rejection.

Read the full file on GitHub · 82 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. 5d ago First seen · 82 lines · 1,117 tokens per session scan A 1631bfb7e103

Subscribe to this mod's changes

mcp-browser-bridge CLAUDE.md is an instructions file published in the GitHub repository adbarc92/mcp-browser-bridge (1 stars, last pushed 7d ago), licensed MIT. It adds 1,117 tokens to every session, about $0.0056 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

ai-agentsai-toolsbrowser-automationchrome-extensionmcpmodel-context-protocol
Related

Other instructions, from other repositories

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 · 5,182 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

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).

microsoft/vscode · 5,001 tokens

langchain AGENTS.md

AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,469 tokens

spec-kit AGENTS.md

AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.

github/spec-kit · 7,104 tokens