Lenny Skills is a collection of product-management and engineering workflows for Claude Code and other AI agents, covering areas such as strategy, research, planning, shipping, growth, and hiring. Each skill gives an agent specialized guidance, frameworks, checklists, or templates for product work, and the catalogue contains many of these skills.
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 skills add RefoundAI/lenny-skills --skill writing-prdsgit clone --depth 1 https://github.com/RefoundAI/lenny-skillsWrote 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/skills/refoundai/lenny-skills/writing-prds)<a href="https://agentmods.dev/skills/refoundai/lenny-skills/writing-prds"><img src="https://agentmods.dev/badge/skills/refoundai/lenny-skills/writing-prds/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/skills/refoundai/lenny-skills/writing-prds"><img src="https://agentmods.dev/badge/skills/refoundai/lenny-skills/writing-prds.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00026 | $0.01427 |
| Opus 5 | $0.00013 | $0.00714 |
| Sonnet 5 | $0.00005 | $0.00285 |
| Haiku 4.5 | $0.00003 | $0.00143 |
Grade A, and why
writing-prds 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 10d 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 — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Writing Product Requirement Documents
Define clear problems and bounded solutions to maximize team velocity and creative output.
Help the user with writing product requirement documents using insights from 14 guests and posts across Lenny's Podcast and Newsletter.
How to Help
- Drafting the core problem - Assist in articulating a concise problem statement that is agnostic of any specific solution.
- Establishing success metrics - Help define specific, measurable outcomes that will act as a filter for future feature requests.
- Defining project boundaries - Guide the user through narrowing fuzzy requests into a bounded concept using shaping techniques.
- Reviewing for clarity - Audit existing drafts for brevity, readability, and technical awareness to prevent micromanagement.
Core Principles
Design for functional prototyping
Jenny Wen: "We used to go off and make this two-year, five-year, 10-year vision even. Now it becomes a vision that's three to six months out, and isn't necessarily creating this beautiful deck, sometimes just creating a prototype that points people in the right direction."
Design should focus on short term functional prototyping rather than static long term planning to keep up with AI driven engineering speeds.
Shape project boundaries early
Ryan Singer: "What we need to do in a shaping session is we come out with some kind of diagram where engineers, product and design, they're saying, "We understand that." So the first thing is we are not going to start something unless we can see the end from the beginning."
Use high intensity collaborative sessions with design and engineering to create a shared understanding of boundaries before development begins.
Center documents on the problem
From "Examples and templates of 1-Pagers and PRDs": "Problem-oriented: They crystallize the problem being solved in a few strong sentences—ideally near the top of the document—to focus the brainpower of every teammate in the same direction."
What ships with it
2 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.
- 10d ago First seen · 95 lines · 26 tokens per session scan A efd86c6e2f37
writing-prds is a skill published in the GitHub repository RefoundAI/lenny-skills (1,323 stars, last pushed 1mo ago), licensed MIT. It adds 26 tokens to every session and 1,427 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 2026-09-03.
Other skills, from other repositories
llama-cpp
Run LLM inference with llama.cpp on CPU, Apple Silicon, AMD/Intel GPUs, or NVIDIA — plus GGUF model conversion and quantization (2–8 bit with K-quants and imatrix). Covers CLI, Python bindings, OpenAI-compatible server, and Ollama/LM Studio integration. Use for edge deployment, M1/M2/M3/M4 Macs, CUDA-less…
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior. 4-phase root cause investigation — NO fixes without understanding the problem first.
github-auth
Set up GitHub authentication for the agent using git (universally available) or the gh CLI. Covers HTTPS tokens, SSH keys, credential helpers, and gh auth — with a detection flow to pick the right method automatically.
ideation
Generate project ideas through creative constraints. Use when the user says 'I want to build something', 'give me a project idea', 'I'm bored', 'what should I make', 'inspire me', or any variant of 'I have tools but no direction'. Works for code, art, hardware, writing, tools, and anything that can be made.
notion
Notion API for creating and managing pages, databases, and blocks via curl. Search, create, update, and query Notion workspaces directly from the terminal.
ocr-and-documents
Extract text from PDFs and scanned documents. Use webextract for remote URLs, pymupdf for local text-based PDFs, marker-pdf for OCR/scanned docs. For DOCX use python-docx, for PPTX see the powerpoint skill.