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.
/plugin marketplace add core0-io/nionpx agentmods add plugins/core0-io/nio/claude-codegit clone --depth 1 https://github.com/core0-io/nioGrade A, and why
nio 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 yesterday.
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.
What it actually says
{
"name": "nio",
"version": "2.5.1",
"description": "Nio — Execution assurance and observability for autonomous AI agents. Dynamic guard, static scan, OTEL collector.",
"author": {
"name": "core0-io",
"url": "https://github.com/core0-io"
},
"homepage": "https://github.com/core0-io/nio",
"repository": "https://github.com/core0-io/nio",
"license": "Apache-2.0",
"keywords": ["nio", "nio-agent-guard", "agent-guard", "nio-agent-harness", "agent-harness", "ai-agent-harness", "ai-agent-security", "llm-agent-safety", "prompt-injection-defense", "mcp-security", "runtime-protection", "execution-assurance", "agent-observability", "agent-protection", "claude-code", "scanner", "otel"]
}
What ships with it
1 file beside plugin.json in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- yesterday First seen · 14 lines scan A f3c6937782ad
nio is a plugin published in the GitHub repository core0-io/nio (19 stars, last pushed 10d ago), licensed Apache-2.0. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-08-30.
Other plugins, from other repositories
agent-harness-generator
MetaHarness — mint a custom AI agent harness from any repo. Paste a GitHub URL or start blank; output runs on Claude Code, OpenAI Codex, pi.dev, Hermes, OpenClaw, or RVM. WASM kernel (Rust → wasm-bindgen + NAPI-RS), 6 hosts, witness-signed Ed25519 releases, GCP Secret Manager validation. Browser Studio + npx metaharne.
metaharness
MetaHarness Marketplace: mint a custom, branded AI agent harness from any repo — runs on Claude Code, OpenAI Codex, pi.dev, Hermes, OpenClaw, RVM, Copilot, OpenCode, or GitHub Actions. WASM kernel, witness-signed releases, npx CLI.
ardur-claude-code-hook
Ardur runtime governance for Claude Code: mission-bound deny gating and signed Execution Receipts on tool calls.
knox
Security enforcement layer for Claude Code. Blocks dangerous commands, audits every tool call, detects prompt injection.
hardstop
Plugin marketplace listing 1 plugin: hs.
hs
Pre-execution safety layer that blocks dangerous shell commands and credential file reads using pattern matching + LLM analysis. Fail-closed design.