rubber-ducky SKILL.md skillA
rubber-ducky from harnessprotocol/harness-kit is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add harnessprotocol/harness-kit/rubber-ducky@git:20261022.97b92e1Pins git:20261022.97b92e1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- harnessprotocol/harness-kit
- Path
plugins/rubber-ducky/skills/rubber-ducky/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261022.97b92e1, committed Oct 22, 2026
- First version recorded
- Jun 5, 2026
- Size
- 10,310 bytes
- Repository stars
- 10
- License
- Apache-2.0
Use when you've planned a non-trivial change and are about to implement it, finished a complex or multi-file piece of work, just wrote tests, or are stuck on repeated failures or unexpected results — and any time the user says "rubber duck this", "rubber ducky", "get a second opinion", "sanity-check my plan", "poke holes in this", "what am I missing", "critique my approach", "review this before I build it", or "/rubber-ducky". Spawns independent read-only critics on DIFFERENT Claude models…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Rubber Ducky A built-in critic. Before committing to a non-trivial change, you stop, articulate your current thinking, and have it scrutinized by independent reviewers running on **different models** than the one driving this session. Unlike a real rubber duck, this one talks back: it returns a structured critique you can act on. ## Why this works Rubber-duck debugging works because *articulating* your reasoning forces the gaps into view. This version adds two things a desk toy can't: 1. **It talks back.** The reviewers return concrete, categorized feedback — not silence. 2. **It doesn't share your blind spots.** The reviewers run on the two Claude models you are *not* using right now, with a clean context. A model that didn't produce the work is far more likely to see what's wrong with it. You get genuinely independent perspectives, not a re-run of the same reasoning that produced the plan. The single highest-leverage moment is **after you've planned a change but before you've written the code**. A design flaw caught here costs a paragraph to fix; caught after implementation it costs a rewrite. ## rubber-ducky vs /review …
Read the whole file at its exact version.
How to install
mdr add harnessprotocol/harness-kit/rubber-ducky@sha256:c3c11695be131103The line at the top of this page pins the label git:20261022.97b92e1, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_rw46pnt6ubuyreaj)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jun 5, 2026 and Oct 22, 2026, about one every 139 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261022.97b92e1 latest | 2026-10-22 | 97b92e1 | 10,310 B | A | view · diff |
| git:20260605.3e8524e | 2026-06-05 | 3e8524e | 9,083 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (10310 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
harnessprotocol/harness-kit · 10 stars · license Apache-2.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_rw46pnt6ubuyreaj GET https://markdownregistry.com/api/v1/resolve?ref=harnessprotocol/harness-kit/rubber-ducky GET https://markdownregistry.com/api/v1/blob/c3c11695be1311038c3e4c70ef7da0c13ed96d2f74c5963eb4f915f382cfde2c
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.