Agent skill

Marketplace Fundamentals

by RefoundAI in RefoundAI/lenny-skills

Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale.

MITAuto-check passed

Install Marketplace Fundamentals

skills CLI
$ npx skills add RefoundAI/lenny-skills --skill marketplace-fundamentals -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install RefoundAI/lenny-skills marketplace-fundamentals --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/RefoundAI/lenny-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/marketplace-fundamentals .claude/skills/marketplace-fundamentals && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
marketplace-fundamentals
GitHub stars
1.4k
Token cost
~2k tokens
SKILL.md length
1,191 words
Files
3 (incl. references)
Skills in repo
76
Repo updated
First seen
Licence
MIT

At a glance

Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale.

  • Works in 4 steps: Diagnose the stage - Identify if the… → Pinpoint the hard side - Help the user… → Evaluate the value proposition - Assess… → …
  • SKILL.md covers How to Help, Core Principles, Templates & Frameworks and Questions to Help Users, plus 3 more sections
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Marketplace Fundamentals is an agent skill from RefoundAI/lenny-skills. Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale.

Its SKILL.md is about 2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including reference files (for example `references/artifacts.md` and `references/guest-insights.md`).

The repository describes itself as: 86 product management skills from Lenny's Podcast for Claude Code and AI agents. Hiring, user research, strategy, shipping, and more. The licence is MIT.

Example prompts

  • “/marketplace-fundamentals”

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

  1. Diagnose the stage - Identify if the user is in the bootstrapping, liquidity-seeking, or scaling phase of their marketplace.
  2. Pinpoint the hard side - Help the user determine which side of the market (supply or demand) is the primary constraint and needs focus.
  3. Evaluate the value proposition - Assess if the platform offers a 10x improvement in convenience, price, or variety compared to traditional…
  4. Select a growth strategy - Recommend specific tactics like single-player mode, geographic constraints, or category niches to build density.

What it can do on your machine

Read from SKILL.md and the folder at commit 13598cc. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md.

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Marketplace Fundamentals loads about 2k tokens when it runs, and up to ~40k if it reads all its reference files. Until then it costs about 48 tokens; SKILL.md has 1,191 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~48
When it runs · the whole SKILL.md, loaded when a task matches
~2k
With references · SKILL.md plus every file in references/, read only if the agent opens them
~40k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from RefoundAI/lenny-skills at commit 13598cc, republished under its MIT licence (© RefoundAI). 1,191 words, ~2,049 tokens.

Download SKILL.mdSave it as .claude/skills/marketplace-fundamentals/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.
name
marketplace-fundamentals
description
Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale.

Marketplace Fundamentals

Build, bootstrap, and scale a self-sustaining ecosystem of buyers and sellers.

Help the user with marketplace fundamentals using insights from 7 guests and posts across Lenny's Podcast and Newsletter.

How to Help

  1. Diagnose the stage - Identify if the user is in the bootstrapping, liquidity-seeking, or scaling phase of their marketplace.
  2. Pinpoint the hard side - Help the user determine which side of the market (supply or demand) is the primary constraint and needs focus.
  3. Evaluate the value proposition - Assess if the platform offers a 10x improvement in convenience, price, or variety compared to traditional alternatives.
  4. Select a growth strategy - Recommend specific tactics like single-player mode, geographic constraints, or category niches to build density.

Core Principles

Nail the Value Exchange First

Benjamin Lauzier: "If you don't have product market fit, and if you don't have a good enough growth strategy for at least one side of your marketplace, just forget about all this marketplace stuff. Focus on this core exchange of value, go deep with one side of the marketplace and see if you can rely on some crutch, some hack for the other side for time being."

Before focusing on complex economic ratios, ensure the core transaction provides enough value to both sides to sustain a growth strategy. Identify the most difficult side of the market to acquire and concentrate early resources there.

Build Standalone Value

Ramesh Johari: "The moral is a marketplace business never starts as a marketplace business, because what we think of as a marketplace business is something which at scale is removing the friction of the two sides finding each other. But when you start, you don't have that scale."

Marketplaces struggle at low scale, so you must offer a high friction utility problem that provides value before critical mass is reached. This helps bootstrap the network by giving users a reason to join without existing liquidity.

Empower Supply to Adapt

Tim Holley: "Our sellers are incredibly astute business people. And if you had been making wedding dresses, and you know how to sew, and you've got material, and you've got a bit of time, making a mask is quite a simple task. And so we just saw this huge surge of demand, and then supply rising to meet it."

Maximize growth by helping your existing supply base apply their skills to new and high demand trends. Use platform signals to show sellers where emerging demand is going so they can adjust their offerings.

Connect Independent Parties

Benjamin Lauzier: "And I think on paper what makes a marketplace is pretty straightforward, it's two or more sides that are distinct from one another, and they provide value to each other, and then you have an intermediary trying to facilitate that exchange of value in the middle."

A true marketplace connects autonomous parties that provide mutual value. Verify that your two target audiences are distinct and provide independent value to each other through the platform interface.

Aggregate and Assume Burden

Camille Hearst: "Which is why I actually think it's great that there's platforms who have stepped in and said, 'Hey, we see an opportunity. Let us insert ourselves in the center, let us aggregate, and let us do the hard work of pricing and payment and tax and finance and actually create value where it would be really hard for an individual person who's a creator to do all of this work and facilitate that connection.'"

Create unique value by aggregating supply and demand and then assuming the administrative or financial burdens that individuals cannot manage on their own. This central facilitation makes connections possible that were previously too difficult.

Stabilize with SaaS Tools

Dan Hockenmaier: "If you're building a SaaS business, you're a construction worker, you're building the product and the features and selling it, and it's this very linear thing. For a marketplace, you're like messing with this ecosystem that you don't actually really understand how it works."

Integrate software tools that provide linear and predictable value to participants. These tools help retain users and provide immediate utility while the unpredictable marketplace liquidity is still developing.

Show full SKILL.md (506 more words)Show less

Templates & Frameworks

  • 7+7 Marketplace Business Evaluation Framework (Evaluating a (marketplace) business idea) - A two-tier framework for evaluating marketplace businesses: first evaluate the general business (7 criteria), then evaluate marketplace-specific dynamics (7 cri
  • 5 Reasons Marketplaces Fail (Why marketplaces fail) - A taxonomy of the five most common fatal issues that kill marketplace businesses, ordered by prevalence. Used to diagnose which failure mode is most likely thre
  • Five Tactics for Solving the Marketplace Cold Start Problem (This Week #2: Tackling the chicken-and-egg problem, building a growth team from scratch, and addressing overlap with PM peers 🤔) - A framework of five proven tactics marketplace companies use to overcome the chicken-and-egg problem when launching with zero users and data
  • Atomic Network Launch Checklist (The Atomic Network) - A set of principles and steps distilled from the chapter for launching a networked product's first atomic network.
  • Single-Player Mode Supply Acquisition Strategy (How to Kickstart and Scale a Marketplace Business – Part 3: Cracking the Chicken-and-Egg Problem 🐣 - Growing Initial Supply) - Bootstrap one side of a marketplace by offering that side a standalone tool valuable on its own, before the network effects exist
  • Three Routes to Marketplace Success (How marketplaces win) - A framework identifying the three primary ways marketplaces win on the demand side: (1) Increasing convenience, (2) Lowering price, (3) Unlocking desirable supp
  • Marketplace Scaling Enforcement Stack (The inside story of Facebook Marketplace) - The enforcement and trust infrastructure Facebook built as Marketplace scaled internationally
  • Six Strategies for Building Marketplace Trust (How to build trust in a marketplace) - A comprehensive framework of six distinct strategies for building trust in a new marketplace, sourced from founders and early growth leaders at successful marke

See references/artifacts.md for the full list with details.

Questions to Help Users

  • "Which side of your marketplace is harder to acquire and retain today?"
  • "What utility does your product provide to a single user when no one else is on the platform?"
  • "Is your target market defined by a current of change that creates natural momentum?"
  • "What is the smallest possible unit of density, or atomic network, needed for your marketplace to work?"
  • "Does your marketplace offer a 10x improvement in price, convenience, or variety over existing non-marketplace options?"
  • "What is the specific transaction cost or search friction you are removing for your users?"

Common Mistakes to Flag

  • Scaling before high fill rates - Scaling prematurely before ensuring high transaction completion rates leads to irreversible user churn and wasted growth spend.
  • Searching for hacks over quality - Solving the chicken and egg problem requires focusing on first principles like selection and delivery quality rather than searching for viral silver bullets.
  • Ignoring the fatal flaw - Marketplace failure is rarely generic and usually stems from one specific risk in demand, supply, liquidity, or unit economics that wasn't diagnosed early.
  • Building for the mainstream too early - Maintaining service quality becomes exponentially harder as you transition from early adopters to the mainstream, requiring early manual onboarding and strict standards.

Deep Dive

For all 45 sourced insights from 7 guests, see references/guest-insights.md

  • Supply Demand Balance
  • Marketplace Liquidity Take Rates

© RefoundAI, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 2 other files (references) in skills/marketplace-fundamentals of RefoundAI/lenny-skills.

  • SKILL.md
  • references/artifacts.md
  • references/guest-insights.md

Open the folder on GitHubat commit 13598cc

Compare with similar skills

Marketplace Fundamentals next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Marketplace Fundamentals compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Marketplace Fundamentals this skillRefoundAI/lenny-skills1.4k—~2kAutomated safety check: PassMIT
Local Businessthedaviddias/Front-End-Checklist74k—~589Automated safety check: PassMIT
Video Understandcalesthio/OpenMontage66k—~841Automated safety check: PassAGPL-3.0
Business Continuitysickn33/agentic-awesome-skills47k2 repos~4.1kAutomated safety check: PassMIT
Longbridge Fundamentalssickn33/agentic-awesome-skills47k1 repos~1.9kAutomated safety check: PassMIT
Business Modelphuryn/pm-skills27k—~1.4kAutomated safety check: PassMIT

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Questions about Marketplace Fundamentals

What does Marketplace Fundamentals do?

Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale. Marketplace Fundamentals is an agent skill from RefoundAI/lenny-skills. Help users understand the core mechanics of marketplace businesses, from solving the cold start problem to maintaining quality and preventing platform leakage at scale.

How do I install Marketplace Fundamentals in Claude Code?

Run `npx skills add RefoundAI/lenny-skills --skill marketplace-fundamentals -a claude-code`. Or copy the skill folder (skills/marketplace-fundamentals in RefoundAI/lenny-skills) into .claude/skills/marketplace-fundamentals in your project. Claude Code loads it when a task matches its description.

How do I install Marketplace Fundamentals in Codex?

Run `npx skills add RefoundAI/lenny-skills --skill marketplace-fundamentals -a codex`. Or copy the skill folder (skills/marketplace-fundamentals in RefoundAI/lenny-skills) into .agents/skills/marketplace-fundamentals in your project. Codex loads it when a task matches its description.

Can I use Marketplace Fundamentals in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add RefoundAI/lenny-skills --skill marketplace-fundamentals -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/marketplace-fundamentals, .gemini/skills/marketplace-fundamentals, .github/skills/marketplace-fundamentals and .opencode/skills/marketplace-fundamentals in your project.

What does Marketplace Fundamentals need to run?

SKILL.md names no scripts, command-line tools or credentials: Marketplace Fundamentals is instructions for the agent only.

Does Marketplace Fundamentals access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Marketplace Fundamentals safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Marketplace Fundamentals use?

Marketplace Fundamentals is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Marketplace Fundamentals use?

About 2k tokens (SKILL.md is roughly 8.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 38k tokens, read only when the agent opens those files.

What are the alternatives to Marketplace Fundamentals?

Skills that share tags, products or a category with Marketplace Fundamentals: Local Business (thedaviddias/Front-End-Checklist, 74k stars), Video Understand (calesthio/OpenMontage, 66k stars), Business Continuity (sickn33/agentic-awesome-skills, 47k stars) and Longbridge Fundamentals (sickn33/agentic-awesome-skills, 47k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Marketplace Fundamentals?

RefoundAI (a GitHub organization) maintains it in RefoundAI/lenny-skills, which has 1,382 GitHub stars. The repository holds 76 skills in this directory. The repository was last updated on July 16, 2026.

Source: RefoundAI/lenny-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.