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Show HN: Geiger – See every AI agent on your machine and what it can touch

read original get YubiKey 5C NFC Security Key → more articles
Why This Matters

Geiger is a no-install CLI tool that inventories every AI agent, MCP server, plugin, and hook on a machine and explains in plain language what each can access. As agent harnesses and plugin ecosystems explode in popularity, most users have no idea how many programs on their machine can execute commands, read files, or hold credentials. It reframes AI agent sprawl as an auditable attack surface rather than an invisible one.

Key Takeaways
Worth a Look

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geiger

A Geiger counter for AI agents.

One read-only command that inventories every AI agent, harness, MCP server, plugin, and AI extension on a machine — and tells you, in plain language, what each one can touch.

npx geiger-scan

No install. No account. No telemetry. Reads configs and directories, writes nothing (unless you ask for --json yourfile.json ).

Why this exists

In August 2026, an open-source agent harness went from zero to 200,000+ GitHub stars in three weeks. Its plugin ecosystem passed 13,000 repositories in the same window. One-click desktop clients appeared the same day it launched. Instagram carousels now teach office workers to install all of it.

Every one of those installs is a program that can execute commands, read files, and hold credentials — configured in dotfiles nobody looks at twice. Ask yourself the question this tool answers: what is actually running on this machine, and what can it reach? Most people cannot answer it. Now it's one command.

What a scan looks like

GEIGER · a Geiger counter for AI agents machine dev-laptop · 2026-09-06 12:24 UTC · read-only · no telemetry ────────────────────────────────────────────────────────────── 9 findings across 3 ecosystems · 7 can execute code · 1 credential in config files claude-code (6) Claude Code agent [EXECUTES] [BROAD-FILESYSTEM] [NETWORK] origin: registry · @anthropic-ai/claude-code magic (Claude Code · global) MCP server [EXECUTES] [HOLDS-SECRETS] [BROAD-FILESYSTEM] origin: registry · @21st-dev/magic@latest credential: "API_KEY" — opaque value under a credential-named key · ~/.claude.json note: wrapped by a policy agent (domainguard-agent.exe) — enforcement layer in front of the server hooks: UserPromptSubmit, PreToolUse hook [EXECUTES] note: hooks execute without a prompt each time their event fires ...

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