What does this skill do, and when should you use it?
Charlie CFO is a Claude Code skill that acts as an AI financial advisor for self-funded, profitable startups, named after Charlie Munger and his principle that capital discipline is a competitive advantage. It provides decision frameworks for cash management, runway calculations, unit economics (LTV:CAC), capital allocation, hiring ROI, burn rate analysis, working capital optimization, and forecasting. The content is pure knowledge guidance with concrete benchmarks (LTV ≥ 3x CAC, 24-36 months runway, Rule of 40) plus reference docs covering real companies like Mailchimp, Zapier, and Basecamp. It suits founders of self-funded companies who lack a dedicated CFO.
The skill activates when users ask strategic financial questions, answering with frameworks defined in SKILL.md: calculating and evaluating runway (target 24-36 months), analyzing burn multiple, assessing unit-economics health (LTV ≥ 3x CAC, CAC payback <12 months, 70-80% gross margin), evaluating hiring and investment decisions via Rule of 40 and a <12-month payback standard, optimizing the cash conversion cycle and AR/AP strategy, producing driver-based forecasts via an MRR buildup model and 13-week cash flow scenarios, and maintaining a key metrics dashboard (NRR >100%, monthly churn <2%, customer concentration warnings). Detailed formulas and industry benchmarks live in references/metrics-benchmarks.md, with case studies in references/case-studies.md.
- A bootstrapped SaaS founder weighing a hire asks whether the role directly contributes to revenue, time-to-productivity, and whether the hiring ROI justifies it
- A startup founder wants to know how much cash runway to hold and how to split operating, contingency, and growth reserves
- A team without a CFO checks whether its LTV:CAC ratio, CAC payback, and other tracked metrics are healthy
- A founder building a revenue forecast wants driver-based planning with an MRR buildup model and three-scenario outlook instead of static percentages
- An operations lead optimizes working capital: shortening the cash conversion cycle, setting AR collection rhythms, and evaluating annual-prepay discount offers
How do you install this skill?
- All financial benchmark figures (revenue per employee, NRR, prepay discount effects, etc.) are unsourced; verify independently before use.
- The referenced references/metrics-benchmarks.md and references/case-studies.md were not present in the reviewed material and remain unverified.
- No Chinese-language support; several benchmarks are US-market specific and may not generalize.
- No version number or update path declared; content may become stale without maintenance signals.
- This is general guidance, not personalized financial advice; consult a professional for major decisions.
Run in Claude Code: npx skills add EveryInc/charlie-cfo-skill. The repo is MIT-licensed with SKILL.md as the skill entry point. The exact post-install file location is not documented in the source.
git clone --depth 1 https://github.com/EveryInc/charlie-cfo-skill.git ~/.claude/skills/charlie-cfo-skillGenerated from the source repository and skill path; it copies only this skill's folder. If the author's install steps above differ, follow those first. To scope it to one project, replace ~/.claude/skills with that project's .claude/skills.
How do you use this skill?
Once installed, send your agent any of these to trigger it:
- Should we make this hire?
- How much runway do we need?
- What metrics should I track?
- How do I forecast revenue?
After installation, the skill activates automatically on natural-language financial questions such as: "Should we make this hire?", "How much runway do we need?", "What metrics should I track?", "How do I forecast revenue?", or "What's a healthy LTV:CAC ratio?".
What are this skill's strengths and limitations?
- Highly specific, actionable numeric benchmarks (LTV ≥ 3x CAC, 24-36 months runway, spending as % of ARR by function) rather than vague advice
- Purpose-built for bootstrapped companies, explicitly contrasting their logic with VC-backed peers (40-70% higher revenue per employee, ~95% of ARR total spend)
- Includes reference docs with case studies from Mailchimp, Zapier, Basecamp, ConvertKit, and Zoho
- Pure knowledge skill with no scripts or external dependencies — low setup friction, MIT licensed
- Benchmark figures are compiled by the skill's author; the source does not state their data provenance or validation method
- Purely advisory — it does not read your actual financials or generate model files; users must plug in their own numbers
- Explicitly designed for bootstrapped companies; VC-backed, burn-heavy startups may find its philosophy a poor fit
- No test suite, and the contents of the reference docs (metrics-benchmarks.md, case-studies.md) cannot be verified from the source material
How does this skill compare with similar options?
Side by side with related skills; every score comes from the same FSRS standard.
| Skill | FS score | Stars | Last updated | License |
|---|---|---|---|---|
| Charlie CFO Skill this page | 53 · Use with care | ★ 325 | 8mo ago | MIT |
| Private Equity Unit Economics ✓ Anthropic · Official | 52 · Use with care | ★ 40k | 1mo ago | Apache-2.0 |
| Earnings Review: Deep Dive into Primary Sources | 52 · Use with care | ★ 17k | 14d ago | MIT |
| Investment Proposal Builder ✓ Anthropic · Official | 44 · Not recommended | ★ 40k | 1mo ago | Apache-2.0 |
| Income Investment: Durable & Opportunistic Distribution Analysis | 59 · Recommended | ★ 17k | 14d ago | MIT |
How did FollowSkills review this skill?
Purely advisory skill: no scripts, no external calls, no sensitive-data handling or destructive operations, so risk surface is minimal; but data sources and benchmark provenance are undeclared, publisher is unverified, and data-flow/attribution disclosure is incomplete — deducted to 17.
Content is internally consistent with no script dependencies to break; however, as a pure guidance skill there is no design for abnormal inputs, edge cases, or failure feedback. Static cap of 10 applies; deducted to 9.
Description clearly names the audience (bootstrapped startups), trigger questions, and topic scope, supporting semantic invocation; but non-fit boundaries (VC-backed firms, non-SaaS industries) are undeclared, there is no Chinese-language support, and several benchmarks may not generalize outside the US — deducted to 10.
Clear information architecture, README, MIT license, install notes and usage examples; but the two referenced references/ files were not present in the review material, and versioning, changelog, and maintenance responsibility are missing — deducted to 9.
Offers a coherent set of CFO frameworks (runway, LTV:CAC, Rule of 40, 13-week cash flow) with real marginal value for the target user; but all benchmark figures are unsourced with no example outputs or case verification, so output quality is unverifiable — static cap 7, deducted to 5.
Author-assertive content only: revenue-per-employee benchmarks, churn improvements from annual prepay, and similar key figures have no citations or third-party corroboration; the referenced case-study file is not visible — static cap 5, deducted to 3.
Open a dimension to read why it scored that way
Evidence confidence：Low — Mostly static review, author material or a limited demo; useful for discovery, not high-risk decisions.
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