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.
npx agentmods add instructions/robhicks/browser-mcp-bridge/claude-mdgit clone --depth 1 https://github.com/robhicks/browser-mcp-bridgeWrote 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.
[](https://agentmods.dev/instructions/robhicks/browser-mcp-bridge/claude-md)<a href="https://agentmods.dev/instructions/robhicks/browser-mcp-bridge/claude-md"><img src="https://agentmods.dev/badge/instructions/robhicks/browser-mcp-bridge/claude-md.svg" alt="Measured on agentmods" height="20"></a>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 | $0.01684 | $0.01684 |
| Opus 5 | $0.00842 | $0.00842 |
| Sonnet 5 | $0.00337 | $0.00337 |
| Haiku 4.5 | $0.00168 | $0.00168 |
Grade A, and why
browser-mcp-bridge CLAUDE.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 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
# or: curl http://localhost:6009/health How it starts
The opening of the file, as written. The whole thing — 226 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.
Project Architecture
This is a Browser MCP Bridge - a two-part system that connects browser extension data with Claude Code through the Model Context Protocol (MCP):
- Browser Extension (
extension/directory) - Chrome extension that captures browser data, DOM snapshots, console messages, network activity, and developer tools information - HTTP MCP Server (
server/directory) - Node.js server that exposes browser data to Claude Code through 11 specialized MCP tools and dynamic resources
Core Communication Flow
- Extension captures browser data via content scripts, background workers, and DevTools APIs
- WebSocket connection (port 6009) bridges extension and MCP server
- HTTP MCP Server allows multiple Claude Code instances to connect to the same server
- Multi-tab support with tabId-based tool targeting
Key Components
Extension Architecture:
manifest.json- Manifest v3 with extensive permissions (tabs, debugger, scripting, webRequest)background.js- Service worker handling WebSocket communication and tab managementcontent.js- Content script for page data extraction and DOM manipulationinject.js- Injected script for deep page context accessdevtools.html/js+panel.html/js- Custom DevTools panel for advanced inspectionpopup.html/js- Extension popup for connection management
Server Architecture:
server.js- HTTP MCP server with WebSocket server for browser connections- HTTP Transport: Multiple Claude Code instances can connect to the same server
- WebSocket Transport: Browser extensions connect via WebSocket to
/ws - Implements 11 MCP tools:
get_page_content,get_dom_snapshot,execute_javascript,get_console_messages,get_network_requests,capture_screenshot,get_performance_metrics,get_accessibility_tree,get_browser_tabs,attach_debugger,detach_debugger - Dynamic resources for real-time browser data access
- Connection management for multiple browser tabs
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.
- 4d ago First seen · 226 lines · 1,684 tokens per session scan A 8e323294e820
browser-mcp-bridge CLAUDE.md is an instructions file published in the GitHub repository robhicks/browser-mcp-bridge (0 stars, last pushed 4mo ago), licensed MIT. It adds 1,684 tokens to every session, about $0.0084 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other instructions, from other repositories
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).
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.
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.
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.
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).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.