Borrowing it
Nothing to install: this file belongs to bobmatnyc/mcp-browser. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/bobmatnyc/mcp-browser/main/CLAUDE.mdgit clone --depth 1 https://github.com/bobmatnyc/mcp-browserWrote 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/bobmatnyc/mcp-browser/claude-md)<a href="https://agentmods.dev/instructions/bobmatnyc/mcp-browser/claude-md"><img src="https://agentmods.dev/badge/instructions/bobmatnyc/mcp-browser/claude-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.
<a href="https://agentmods.dev/instructions/bobmatnyc/mcp-browser/claude-md"><img src="https://agentmods.dev/badge/instructions/bobmatnyc/mcp-browser/claude-md.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.06134 | $0.06134 |
| Opus 5.5 | $0.02454 | $0.02454 |
| Sonnet 5.5 | $0.01227 | $0.01227 |
| Haiku 4.5 | $0.00613 | $0.00613 |
Grade A, and why
mcp-browser 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 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.
How it starts
The opening of the file, as written. The whole thing — 866 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md - AI Agent Instructions for mcp-browser
Project: MCP Browser - Browser console log capture and control via MCP
Location: /Users/masa/Projects/mcp-browser
Language: Python 3.10+
Architecture: Service-Oriented Architecture (SOA) + Chrome Extension + MCP Server
Last Updated: 2025-12-15
🎯 Priority Index
🔴 CRITICAL Instructions
🟡 IMPORTANT Instructions
🟢 STANDARD Instructions
⚪ OPTIONAL Instructions
🔴 CRITICAL: Architecture Constraints
Service-Oriented Architecture (SOA)
NEVER violate these architectural boundaries:
# ✅ CORRECT: Services communicate through dependency injection
class BrowserService:
def __init__(self, storage_service=None):
self.storage_service = storage_service # Injected dependency
# ❌ WRONG: Direct service instantiation breaks DI
class BrowserService:
def __init__(self):
self.storage_service = StorageService() # Don't do this!
Service Layer Rules:
- All service methods MUST be async - No blocking operations
- 500-line service limit - Enforces single responsibility principle
- Constructor injection only - Dependencies resolved at creation time
- No circular dependencies - Container enforces dependency graph
- Interface segregation - Services expose minimal public APIs
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.
- 2mo ago First seen · 866 lines · 6,134 tokens per session scan A 58b0509b7f2d
mcp-browser CLAUDE.md is an instructions file published in the GitHub repository bobmatnyc/mcp-browser (2 stars, last pushed 10mo ago), licensed MIT. It adds 6,134 tokens to every session, about $0.0245 per session on Opus 5.5. 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.
mcp-browser CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-browser CLAUDE.mdbobmatnyc/mcp-browser | Instructions file | 2 | 10mo ago | MIT | A | 6,134 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | yesterday | MIT | A | 7,461 | Codex, OpenCode |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | yesterday | MIT | A | 4,680 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |