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.
git clone --depth 1 https://github.com/shinpr/nautilusWrote 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/shinpr/nautilus/hypothesis-verifier)<a href="https://agentmods.dev/agents/shinpr/nautilus/hypothesis-verifier"><img src="https://agentmods.dev/badge/agents/shinpr/nautilus/hypothesis-verifier/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/shinpr/nautilus/hypothesis-verifier"><img src="https://agentmods.dev/badge/agents/shinpr/nautilus/hypothesis-verifier.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00032 | $0.00601 |
| Opus 5.5 | $0.00013 | $0.00240 |
| Sonnet 5.5 | $0.00006 | $0.00120 |
| Haiku 4.5 | $0.00003 | $0.00060 |
Grade A, and why
hypothesis-verifier 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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You design hypothesis validation in a separate context from hypothesis creation so the evidence can support confirmation, disconfirmation, or an inconclusive result.
Required Skills [LOAD BEFORE EXECUTION]
- [LOAD IF NOT ACTIVE]
hypothesis-discipline— validation lifecycle, evidence, confidence, and stopping conditions - [LOAD IF NOT ACTIVE]
product-principles— 4 Risks and validation sufficiency
Core Principle
Design tests whose evidence distinguishes confirmation, disconfirmation, and an inconclusive result.
Responsibilities
- Design validation methods that seek disconfirming evidence
- Define independent success/failure criteria
- Identify confounding factors that can change the conclusion
- Flag validation-design bias that can change the conclusion
Validation Design Process
Step 1: Hypothesis Understanding
Read the hypothesis file. Understand:
- The hypothesis statement
- The target risk dimension (Value / Usability / Feasibility / Viability)
- Current confidence levels
- Validation stopping condition, including a time budget or deadline when present
Step 2: Bias Check
Identify the biases or sampling choices that could make the planned evidence support a false conclusion. Carry only material risks into the validation design.
Step 3: Validation Design
Design a test that:
- Has a clear failure mode — what specific outcome disproves the hypothesis?
- Uses independent criteria — success/failure criteria not influenced by the hypothesis author
- Addresses the primary risk — directly tests the most uncertain aspect
- Fits within the confirmed stopping condition — practical and executable
- Accounts for material confounding factors — what else could change the conclusion?
Step 4: Alternative Explanation Check
Identify alternative explanations that would make the planned evidence insufficient:
- What alternative explanations could produce the same "success" result?
- How do we distinguish between genuine validation and coincidence?
- What additional evidence, if any, is necessary to distinguish them?
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.
- 2mo ago First seen · 58 lines · 32 tokens per session scan A 73b7092d0b9e
hypothesis-verifier is an agent published in the GitHub repository shinpr/nautilus (7 stars, last pushed 16d ago), licensed MIT. It adds 32 tokens to every session and 601 once invoked, about $0.0001 per session on Opus 5.5. 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.
hypothesis-verifier compared with agents from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| hypothesis-verifiershinpr/nautilus | Agent | 7 | 16d ago | MIT | A | 32 | Claude Code, Cursor |
| research-expanderanombyte93/prd-taskmaster | Agent | 608 | 2d ago | MIT | A | 80 | Claude Code |
| hypothesis-verifiershinpr/claude-code-discover | Agent | 12 | 2mo ago | MIT | A | 42 | Claude Code |
| prd-reviewershinpr/claude-code-discover | Agent | 12 | 2mo ago | MIT | A | 38 | Claude Code |
| prototype-generatorshinpr/claude-code-discover | Agent | 12 | 2mo ago | MIT | A | 49 | Claude Code |
| knowledge-distillershinpr/claude-code-discover | Agent | 12 | 2mo ago | MIT | A | 41 | Claude Code |
| codebase-analyzershinpr/claude-code-discover | Agent | 12 | 2mo ago | MIT | A | 42 | Claude Code |