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 harnessprotocol/harness-kitnpx agentmods add plugins/harnessprotocol/harness-kit/rubber-duckygit clone --depth 1 https://github.com/harnessprotocol/harness-kitGrade A, and why
rubber-ducky 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 2d 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.
What it actually says
{
"name": "rubber-ducky",
"description": "A constructive critic that gives a second opinion on your own plans, designs, code, and tests — spawning independent read-only reviewers on different Claude models than the one driving the session",
"version": "0.1.0",
"category": "code-quality",
"tags": ["rubber-duck", "second-opinion", "critique", "debugging", "code-review", "multi-model"],
"x-developed-with": "claude-opus-4-8"
}
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.
- 2d ago First seen · 9 lines scan A 8a9ae3f9b48c
rubber-ducky is a plugin published in the GitHub repository harnessprotocol/harness-kit (10 stars, last pushed 3d 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 2026-08-31.
Other plugins, from other repositories
llm-wiki
Plugin marketplace listing 1 plugin: llm-wiki.
llm-wiki-plugin
Build and maintain an LLM-curated personal knowledge base with default local FastEmbed + sqlite-vec search, BM25 fusion, structured evidence, incremental caching, and a compiled graph layer.
mindmap-marketplace
Plugin marketplace listing 1 plugin: mindmap.
mindmap
Generate interactive mind maps from any content — with contradiction detection, gap analysis, source attribution, adaptive layouts, and a persistent knowledge atlas. Outputs interactive React artifacts or portable Markmap files.
vault-pkm
Bidirectional knowledge flow between Claude Code and Obsidian — 20 MCP tools, skills, and hooks for PKM.
humanizer
Rewrite AI-sounding text so it reads naturally without changing what it says.