meshbrow-mcp: Instructions file for Claude Code

CLAUDE.md

meshbrow-mcp CLAUDE.md is an instructions file for Claude Code from meshbrow-dev/meshbrow-mcp. It costs 696 tokens per session, scanned A, original, MIT.

A set of instructions for working on the meshbrow MCP server, a program that lets AI assistants use connected tools. It documents the repository's coding rules, shared Claude Code configuration, and required safety practices.

In plain words
What is it for?
Use it when changing code or configuration in the meshbrow MCP server repository, especially when following its Go, MCP, deployment, and error-handling conventions.
Why use it?
It gives contributors project-specific rules that may not be obvious from the code itself. It also warns which configuration files are synchronized from another repository and should not be edited locally.

Instructions file for Claude Code

Written for Claude Code: SessionStart hook event. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions Claude Code.

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

Reuse

Borrowing it

Nothing to install: this file belongs to meshbrow-dev/meshbrow-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/meshbrow-dev/meshbrow-mcp/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/meshbrow-dev/meshbrow-mcp

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
[![agentmods](https://agentmods.dev/badge/instructions/meshbrow-dev/meshbrow-mcp/claude-md.svg)](https://agentmods.dev/instructions/meshbrow-dev/meshbrow-mcp/claude-md)
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<a href="https://agentmods.dev/instructions/meshbrow-dev/meshbrow-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/meshbrow-dev/meshbrow-mcp/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 696 This file is loaded in full into every session.
When invoked 696 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 $0.00696 $0.00696
Opus 5 $0.00348 $0.00348
Sonnet 5 $0.00139 $0.00139
Haiku 4.5 $0.00070 $0.00070

Measured 6d ago against content hash da9d2de84033, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

meshbrow-mcp 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 6d 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 · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Meshbrow MCP Server

You are working in meshbrow-dev/meshbrow-mcp — the standalone MCP (Model Context Protocol) server, released via GoReleaser + Homebrew (meshbrow-dev/homebrew-tap). This repo is not yet listed in meshbrow-dev/workspace's own CLAUDE.md app table; it is assumed to live at apps/mcp/ there — verify and correct this hook's path-prefix assumption if the team places it elsewhere.

See .claude/skills/go-backend/SKILL.md (Go conventions), .claude/skills/mcp-protocol/SKILL.md (tool definitions and safety rules), and .claude/skills/deployment/SKILL.md (Open-Source Tool Releases section) for conventions.

Shared Claude Code Config

.claude/skills/ and .claude/agents/ in this repo are synced automatically from meshbrow-dev/workspace by the SessionStart hook (.claude/hooks/session-start.sh) whenever this repo is opened directly (e.g. Claude Code on the web) rather than checked out inside the workspace repo. Don't hand-edit files under .claude/skills/ or .claude/agents/ here — edit them in meshbrow-dev/workspace instead, they'll be overwritten on the next session start.

Critical Rules (ALL code changes)

NEVER

  • Return raw error messages to API clients — use structured error responses
  • Log sensitive fields: apiKey, proxyCredentials, fingerprint configs
  • Call Docker/Chromium directly — always go through the Runtime interface
  • Skip input validation on API handlers
  • Use any type in Go — always define concrete types
  • Commit secrets, .env files, or proxy provider credentials
  • Ship without tests for the changed code
  • Ship without updating relevant docs
  • Expose fingerprint internals in API responses (detection vectors)
  • Store proxy passwords unencrypted
  • Allow cross-session network traffic (namespace leak = critical bug)
  • Ship implementation without running tests and confirming they pass
  • Consider a feature "done" with less than 80% test coverage on changed code

ALWAYS

  • Use structured logging (slog in Go, structured JSON)
  • Validate at system boundaries (API handlers, webhook receivers)
  • Use context.Context for cancellation and deadlines
  • Write tests alongside implementation (same commit or immediately after)
  • Run tests after implementation and confirm they pass before marking complete
  • Target ≥ 80% coverage on all changed/new code
  • Use conventional commits: feat:, fix:, docs:, refactor:, test:, chore:
  • Add OpenTelemetry spans for cross-service calls
  • Use database transactions for multi-row operations
  • Clean up network namespaces on session destroy
  • Rotate proxy credentials when sessions end
  • Verify anti-detection on every Chromium update

Read the full file on GitHub · 54 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. 6d ago First seen · 54 lines · 696 tokens per session scan A da9d2de84033

Subscribe to this mod's changes

meshbrow-mcp CLAUDE.md is an instructions file published in the GitHub repository meshbrow-dev/meshbrow-mcp (0 stars, last pushed 17d ago), licensed MIT. It adds 696 tokens to every session, about $0.0035 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.

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