Build README

Scaffold a project's top-level README.md: the first file a stranger sees after git clone, a dependency listing, or a package-registry page. The authoring rubric — what a good README does, the anatomy template, the patterns that work — lives in readme-best-practices.md. This skill is the workflow; the principles doc is the rubric.

Scope is top-level only. Sub-package READMEs inside a monorepo directory, documentation-site landing pages, and GitHub organization profile READMEs are out of scope and refused at the Scope Gate. They serve different audiences and deserve different rubrics.

Workflow sequence: 1. Route → 2. Scope Gate → 3. Elicit → 4. Draft → 5. Safety Check → 6. Review Gate → 7. Save → 8. Test

When to use

Also fires when the user phrases the request as:

"write the project README"
"new README for this repo"

1. Route

Confirm a top-level README.md is the right artifact before asking scaffold-specific questions.

Wrong artifact:

Package/module docstring, not a README → author in the language's native docstring format; not this skill.
A Claude Code skill or rule doc → /build:build-skill or /build:build-rule.
A changelog, contributing guide, or architecture doc → those are sibling markdown files (CHANGELOG.md, CONTRIBUTING.md, ARCHITECTURE.md), not the README — the README links to them.

Wrong scope — recommend an alternative:

Sub-package README (packages/foo/README.md in a monorepo) — the audience is a reader already in the repo, not a stranger; the rubric differs. Hand-write or propose a dedicated /build:build-subpackage-readme pair when demand justifies it.
Docs-site landing page — styled deliverable; the toolchain (Docusaurus, mkdocs, etc.) drives the shape.
GitHub org-profile README (.github/profile/README.md) — marketing surface, not a project entry point.

Right artifact and right scope → proceed to Scope Gate.

2. Scope Gate

Refuse to scaffold when any of these signal:

An existing README.md is already present at the target path and non-trivial (more than ~20 lines of real content, not a stub). Scaffolding over it would discard work. Offer instead to run /build:check-readme <path> and iterate from findings.
No project context available — the target directory has no discernible project (no package.json, pyproject.toml, Cargo.toml, go.mod, Gemfile, pom.xml, or similar). A README for an empty directory is a template, not a README; ask the user to confirm they want a generic skeleton or to initialize the project first.
Target is not a repository root — the path given is several directories deep and is clearly a sub-package. Confirm scope (see Route §1); refuse sub-package READMEs.

If any signal fires, state the signal, name the recommended alternative, and stop. Do not proceed to Elicit.

3. Elicit

If $ARGUMENTS is non-empty, parse it as [project-name] and pre-fill question 1. Otherwise ask, one question at a time:

1. Project name — the single H1. Typically the package name or repo name. Avoid marketing phrases; the H1 is for humans and tools.

2. One-sentence description — what the project is (not what it does). "A Python library for X", "A CLI tool that X", "A service that X". This is the most-read line in the document.

3. Problem statement — 2-3 sentences: what problem does this solve, who is it for. Features answer how; the problem statement answers why I should care.

4. Language / runtime + minimum version — Node 18+, Python 3.10+, Go 1.22+, etc. Populates Prerequisites.

5. Install command(s) — the command a reader would run on a clean machine. Include language identifier for the fenced block (bash, sh, pwsh). Multi-platform? List each with a labeled block.

6. Quickstart command + expected output — the minimal runnable example. If the project is a library, show the smallest import + call that produces visible output.

7. Configuration surface — environment variables, config files, or CLI flags the user must set before running. Omit if none (the scaffold drops the Configuration H2).

8. License — SPDX identifier (MIT, Apache-2.0, GPL-3.0, etc.). Required; the scaffold refuses to omit the License section.

9. Distribution channel — GitHub-only, or does this also ship to npm / PyPI / crates.io / similar? Determines relative-vs-absolute link default (relative for GitHub-only; absolute for package mirrors).

10. Badges to include — CI status, package version, license, coverage. Cap at 5; more is scan-noise. Ask for URLs or accept "standard set for this stack" and propose defaults.

11. Save path — default is README.md at the current working directory. Confirm.

4. Draft

Produce a single conditionalized template. Sections marked (if X) are omitted when intake rules them out.

# <project-name>                                        ← Intake #1

<one-sentence description>                              ← Intake #2

<2-3 sentence problem statement>                        ← Intake #3

<badges block — under title, ~3-5 max>                  ← Intake #10 (if any)

## Prerequisites

- <language/runtime> <min-version>                      ← Intake #4
- <other prerequisites if named>

## Installation

```<lang>
<install command>                                        ← Intake #5
```

<repeat block per platform if multi-platform>

## Usage

```<lang>
<quickstart command>                                     ← Intake #6
```

Expected output:
```
<expected output>
```

## Configuration                                         ← (if Intake #7 non-empty)

| Variable | Default | Required | Description |
|----------|---------|----------|-------------|
| `<VAR>`  | <def>   | yes/no   | <desc>      |

## Troubleshooting                                       ← placeholder; one FAQ entry

**Problem:** <common symptom>
**Cause:** <root cause>
**Fix:** <concrete remediation>

## Contributing

See [CONTRIBUTING.md](CONTRIBUTING.md).

## License

<SPDX-id> — see [LICENSE](LICENSE).                      ← Intake #8

Link style default:

(if Intake #9 = GitHub-only) Use relative links (CONTRIBUTING.md, LICENSE).
(if Intake #9 = package mirror) Use absolute URLs (https://github.com/<owner>/<repo>/blob/main/CONTRIBUTING.md) and prompt for the repo URL.

(if Intake #7 = none) Omit the entire Configuration H2.

Present the draft plus a suggested git add README.md invocation line to the user before any safety checks.

5. Safety Check

Review the draft against the rubric in readme-best-practices.md before presenting. Group the checks:

Structure. Single H1 on first content line. One-sentence description on the next line. 2-3 sentence problem statement follows. H2 sequence in reader-intent order. Heading levels sequential (no H2 → H4 skips).

Commands & code blocks. Every command block carries a language tag. No shell-prompt prefixes ($, >, #). Placeholders marked with <...>. Code-block lines ≤80 characters.

Safety. No real secrets, tokens, credentials, or hostnames in the draft. No pipe-to-shell installers without a documented manual alternative. No destructive commands without a warning callout. Example domains/IPs are RFC-reserved only (example.com, *.test, 127.0.0.1, RFC 5737 ranges).

Completeness. License section present with SPDX identifier and link. Contributing section links to CONTRIBUTING.md. No TODO / FIXME / XXX markers in the draft.

Style. Imperative mood for instructions ("Run npm install", not "You should run…"). No emoji in headings. Prose lines ≤120 characters.

If any check fails, revise the draft before presenting. The Review Gate is for user approval, not correctness recovery.

6. Review Gate

Present the draft (full README content + suggested git add invocation) and wait for explicit user approval before writing any file to disk. Write only after this gate passes.

If the user requests changes, revise and re-present. Continue until the user explicitly approves or cancels. Proceed to Save only on explicit approval.

7. Save

Write the approved README to the path elicited in Step 3.11 (default README.md at the current working directory).

Do not chmod +x — markdown is data, not executable. Do not create sibling files (LICENSE, CONTRIBUTING.md); the README references them, but creating them is out of scope. Prompt the user to add those files separately if they are not yet present.

8. Test

Offer the audit:

"Run /build:check-readme <path> to audit the scaffolded README against structure, safety, completeness, and judgment dimensions?"

The audit is the canonical follow-on; running it once after scaffold catches anything the Safety Check missed.

Anti-Pattern Guards

Omitting the License section — even if the user does not yet have a LICENSE file, the section is required. The scaffold links to a LICENSE file that may not exist yet; that is the prompt to create it, not an excuse to skip the section.
Scaffolding marketing language — the H1 is the project name, not a tagline. The one-sentence description is what it is, not what it promises. Salesy language belongs on a landing page.
Forgetting expected output in Quickstart — the command alone is half the contract. Silence after a command breeds doubt.
Shell prompts in code blocks — $ npm install cannot be copy-pasted. Drop the prompt.
Real secrets in examples — even in a draft. Readers copy-paste before reviewers read.

Key Instructions

Refuse cleanly on Scope Gate signals. Sub-package READMEs and existing non-trivial READMEs are hard refuses with alternatives named.
Write files to disk only after the Review Gate passes.
The License section is always scaffolded — it is not intake-gated. An SPDX identifier is elicited explicitly.
The Configuration H2 is intake-gated — omit when no config surface exists. Empty sections are scan-noise.
Code-block language tags are mandatory on every fenced block. Default to the target shell / language; never empty info-strings.
Use relative links by default; switch to absolute URLs only when Intake #9 flags package-mirror distribution.
Won't scaffold over a non-trivial existing README — offer /build:check-readme instead.
Won't inline real secrets, hostnames, or credentials in examples — use reserved ranges.

Handoff

Chainable to: /build:check-readme (audit the scaffolded README against structure, safety, completeness, and the seven judgment dimensions).