> **before-you-build** — chapter 19 of 180 in [wshobson/agents](https://skillsdocs.com/wshobson/agents).
>
> Book (all chapters, one file): https://skillsdocs.com/wshobson/agents.md
> Machine manifest: https://skillsdocs.com/wshobson/agents/.well-known/agent-skills/index.json
> Install the book: `npx skills add wshobson/agents`
> Upstream: https://github.com/wshobson/agents/blob/main/plugins/before-you-build/skills/before-you-build/SKILL.md @ `main`
> Raw bytes, no header: https://raw.githubusercontent.com/wshobson/agents/main/plugins/before-you-build/skills/before-you-build/SKILL.md
> Base for relative paths: https://raw.githubusercontent.com/wshobson/agents/main/plugins/before-you-build/skills/before-you-build/
> Licence: MIT — https://spdx.org/licenses/MIT.html
>
> Bundled files (1), referenced from this skill's directory:
>   - `references/risk-checklist.md` — https://raw.githubusercontent.com/wshobson/agents/main/plugins/before-you-build/skills/before-you-build/references/risk-checklist.md
>
> Content © its authors, served unmodified. Takedown: https://github.com/kyleledbetter/skillsdocs/issues/new?labels=takedown&title=Takedown+request

<!-- Verbatim upstream SKILL.md follows, YAML frontmatter included. -->

---
name: before-you-build
description: Pre-build product and feature risk review for founders, product managers, and AI-assisted builders. Use this skill when the user is about to build a landing page, MVP, SaaS product, internal tool, agent workflow, or major feature and needs to check demand, positioning, monetization, retention, trust, distribution, and adoption risk before implementation starts.
---

# Before You Build

Run a compact pre-mortem before implementation. The goal is not to block building; it is to identify the highest-risk assumption, the smallest validation step, and the build scope that should be delayed until evidence improves.

## When To Use

Use this skill when a user asks to build or ship:

- A new product, MVP, prototype, landing page, SaaS app, marketplace, content site, agent workflow, or internal tool
- A major feature with unclear adoption, revenue, retention, trust, or distribution impact
- A public launch asset where weak positioning could waste development or promotion effort

Skip this skill when the task is a narrow implementation fix, refactor, test repair, dependency update, or already-validated change with clear acceptance criteria.

## Risk Checklist

Review the idea across these risks:

- **Demand:** Is there evidence that a specific buyer or user urgently wants this?
- **Positioning:** Can the target user understand what it is and why it matters in one sentence?
- **Monetization:** Is there a credible path to payment, budget, or strategic value?
- **Retention:** Is there a reason users would return after the first try?
- **Trust:** Does the product require credibility, data access, integrations, or behavior change that users may resist?
- **Distribution:** Is there a repeatable way to reach the target user?
- **Feature adoption:** For feature work, will the feature change user behavior or just add surface area?

If the verdict is not obvious, use `references/risk-checklist.md` for deeper questions.

## Output Format

Keep the response short and decision-oriented:

1. **Risk verdict:** Low, medium, or high risk, with one sentence explaining why.
2. **Main assumption:** The single assumption most likely to break the project.
3. **Evidence to find first:** The smallest useful signal before building more.
4. **Do next:** One concrete validation step or reduced build scope.
5. **Delay:** What not to build yet.

## Guidance

- Be direct about weak evidence, but avoid dismissing the user's idea.
- Prefer smaller validation steps over large research plans.
- Separate product risk from engineering difficulty.
- If the idea is already validated, say what evidence makes it lower risk and suggest the smallest implementation slice.
- If facts are missing, name the missing evidence instead of inventing market claims.