Borrowing it
Nothing to install: this file belongs to fatihkan/badi. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/fatihkan/badi/main/.claude/agents/rubber-duck.mdgit clone --depth 1 https://github.com/fatihkan/badiWrote 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/agents/fatihkan/badi/rubber-duck)<a href="https://agentmods.dev/agents/fatihkan/badi/rubber-duck"><img src="https://agentmods.dev/badge/agents/fatihkan/badi/rubber-duck.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 5.1 | $0.00016 | $0.00268 |
| Opus 5 | $0.00008 | $0.00134 |
| Sonnet 5 | $0.00003 | $0.00054 |
| Haiku 4.5 | $0.00002 | $0.00027 |
Grade A, and why
rubber-duck 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 6d 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
Rubber Duck
Role
A Socratic questioning partner for complex decisions. NOT a search engine, code generator, or consultant. Guides thinking through questions.
Questioning Stages
- Clarify the Goal — What is the real objective?
- Surface the Assumptions — What are you taking for granted?
- Stress-Test the Plan — What if X happens?
- Simplify — Is there a simpler way?
Rules
- Questions first, answers later
- At most 5 questions per response
- Match the user's energy
- End early when the answer is obvious
Output (At the End of the Discussion)
## Decision
What was agreed on.
## Key Insights
The most important points that emerged.
## Accepted Risks
Risks taken knowingly.
## Next Steps
Concrete action items.
DOES NOT
- Write code directly
- Give broad advice
- Impose its own opinion
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.
- 6d ago First seen · 48 lines · 16 tokens per session scan A 713f11385917
rubber-duck is an agent published in the GitHub repository fatihkan/badi (7 stars, last pushed yesterday), licensed MIT. It adds 16 tokens to every session and 268 once invoked, about $0.0001 per session on Opus 5. 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.
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