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 rules/steipete/agent-rules/mcp-peekaboo-setupgit clone --depth 1 https://github.com/steipete/agent-rulesWrote 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/rules/steipete/agent-rules/mcp-peekaboo-setup)<a href="https://agentmods.dev/rules/steipete/agent-rules/mcp-peekaboo-setup"><img src="https://agentmods.dev/badge/rules/steipete/agent-rules/mcp-peekaboo-setup.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 | $0.00011 | $0.00868 |
| Opus 5 | $0.00005 | $0.00434 |
| Sonnet 5 | $0.00002 | $0.00174 |
| Haiku 4.5 | $0.00001 | $0.00087 |
Grade C, and why
mcp-peekaboo-setup scanned grade C 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.
Harvests environment variableshighData exfiltration
Enumerating or grepping the environment for keys collects credentials unrelated to what the mod says it does.
# Extract API key from .zshrc Copies of this mod
1 near-identical copy found in the catalogue:
- mcp-peekaboo-setup — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MCP Peekaboo Setup
This rule sets up the Peekaboo MCP server, which provides screenshot capture and AI-powered vision analysis capabilities.
Overview
Peekaboo is a Model Context Protocol server that enables Claude to:
- Take screenshots of your screen
- Analyze images using AI vision models
- Support both OpenAI and Ollama providers
Prerequisites
- macOS 14.0+ (Sonoma or later)
- Node.js 20.0+
- OpenAI API key (stored in
~/.zshrc) - Optional: Ollama with vision models installed
Configuration
Add this to your Claude Desktop configuration (~/Library/Application Support/Claude/claude_desktop_config.json):
{
"mcpServers": {
"peekaboo": {
"command": "npx",
"args": [
"-y",
"@steipete/peekaboo-mcp"
],
"env": {
"PEEKABOO_AI_PROVIDERS": "openai/gpt-4o,ollama/llava:latest",
"OPENAI_API_KEY": "<READ_FROM_ZSHRC>",
"PEEKABOO_LOG_LEVEL": "info",
"PEEKABOO_DEFAULT_SAVE_PATH": "~/Desktop"
}
}
}
}
Security Setup
To securely extract the OpenAI API key from ~/.zshrc:
# Extract API key from .zshrc
export OPENAI_API_KEY=$(grep "export OPENAI_API_KEY=" ~/.zshrc | cut -d'"' -f2)
# Update Claude config with the actual key
jq --arg key "$OPENAI_API_KEY" \
'.mcpServers.peekaboo.env.OPENAI_API_KEY = $key' \
~/Library/Application\ Support/Claude/claude_desktop_config.json > tmp.json && \
mv tmp.json ~/Library/Application\ Support/Claude/claude_desktop_config.json
Available Tools
Once configured, you'll have access to:
-
peekaboo_capture_screenshot
- Takes a screenshot of the entire screen or a specific display
- Saves to the default path or specified location
-
peekaboo_analyze_screenshot
- Captures and analyzes a screenshot with AI
- Uses the configured AI providers for vision analysis
Usage Examples
Basic Screenshot
Take a screenshot of my screen
Screenshot with Analysis
Take a screenshot and tell me what application is currently in focus
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 · 134 lines · 11 tokens per session scan C 076a2b7243e7
mcp-peekaboo-setup is a cursor rule published in the GitHub repository steipete/agent-rules (5,694 stars, last pushed 4mo ago), licensed MIT. It adds 11 tokens to every session and 868 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it C with 1 finding (harvests environment variables). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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