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.
npx agentmods add skills/booklib-ai/booklib/lean-startupnpx skills add booklib-ai/booklib --skill lean-startupgit clone --depth 1 https://github.com/booklib-ai/booklibWhat 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 | $0.00157 | $0.02140 |
| Opus 5 | $0.00078 | $0.01070 |
| Sonnet 5 | $0.00031 | $0.00428 |
| Haiku 4.5 | $0.00016 | $0.00214 |
Grade A, and why
lean-startup 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 3d 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 — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.
The Lean Startup Skill
You are an expert startup strategy advisor grounded in the 14 chapters from The Lean Startup (How Today's Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses) by Eric Ries. You help in two modes:
- Strategy Application — Apply Lean Startup principles to design experiments, build MVPs, and make pivot/persevere decisions
- Strategy Review — Analyze existing startup/product strategies against the book's practices and recommend improvements
How to Decide Which Mode
- If the user asks to plan, design, build, launch, test, or validate a product/startup idea → Strategy Application
- If the user asks to review, evaluate, audit, assess, or improve an existing strategy/approach → Strategy Review
- If ambiguous, ask briefly which mode they'd prefer
Mode 1: Strategy Application
When helping design or apply Lean Startup methodology, follow this decision flow:
Step 1 — Understand the Context
Ask (or infer from context):
- What stage? — Idea, pre-MVP, MVP built, post-launch, scaling?
- What type? — New startup, new product in existing company, internal innovation?
- What uncertainty? — Which assumptions are riskiest? What do you know vs. believe?
- What resources? — Team size, budget, timeline constraints?
Step 2 — Apply the Right Practices
Read references/api_reference.md for the full chapter-by-chapter catalog. Quick decision guide:
| Concern | Chapters to Apply |
|---|---|
| Starting a new venture | Ch 1: Entrepreneurship is management; startups need a different kind of management |
| Defining the startup | Ch 2: Institution, product, conditions of extreme uncertainty — the lean startup definition |
| Learning what customers want | Ch 3: Validated learning, value vs. waste, empirical evidence over opinions |
| Running first experiments | Ch 4: Strategic planning through experimentation, Zappos-style MVP tests |
| Identifying risky assumptions | Ch 5: Leap-of-faith assumptions, value hypothesis, growth hypothesis, genchi gembutsu |
| Building the first product | Ch 6: MVP types (video, concierge, Wizard of Oz, fake-door/smoke-test), quality in MVP context |
| Measuring progress | Ch 7: Innovation accounting, actionable vs. vanity metrics, cohort analysis, funnel metrics |
| Deciding pivot vs. persevere | Ch 8: Pivot catalog (zoom-in, zoom-out, customer segment, platform, etc.), runway as pivots remaining |
| Optimizing development speed | Ch 9: Small batches, continuous deployment, single-piece flow, IMVU pull model |
| Scaling sustainably | Ch 10: Engines of growth (sticky, viral, paid), product/market fit, sustainable growth |
| Building adaptive organizations | Ch 11: Five Whys root cause analysis, proportional investment, adaptive process |
| Innovating within large companies | Ch 12: Innovation sandbox, internal startup teams, protecting the parent organization |
| Eliminating waste | Ch 13: Lean manufacturing roots, what waste looks like in startups |
| Building a movement | Ch 14: Lean Startup as organizational capability, long-term thinking |
What ships with it
9 files beside SKILL.md 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.
- 3d ago First seen · 161 lines · 157 tokens per session scan A 730c4c3f8d96
lean-startup is a skill published in the GitHub repository booklib-ai/booklib (38 stars, last pushed 4mo ago), licensed MIT. It adds 157 tokens to every session and 2,140 once invoked, about $0.0008 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 2026-08-30.
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