Next.js Documentation Updater

Guides you through updating Next.js documentation based on code changes on the active branch. Designed for maintainers reviewing PRs for documentation completeness.

Quick Start

1. Analyze changes: Run git diff canary...HEAD --stat to see what files changed
2. Identify affected docs: Map changed source files to documentation paths
3. Review each doc: Walk through updates with user confirmation
4. Validate: Run pnpm lint to check formatting
5. Commit: Stage documentation changes

Workflow: Analyze Code Changes

Step 1: Get the diff

# See all changed files on this branch
git diff canary...HEAD --stat

# See changes in specific areas
git diff canary...HEAD -- packages/next/src/

Step 2: Identify documentation-relevant changes

Look for changes in these areas:

Source Path	Likely Doc Impact
packages/next/src/client/components/	Component API reference
packages/next/src/server/	Function API reference
packages/next/src/shared/lib/	Varies by export
packages/next/src/build/	Configuration or build docs
packages/next/src/lib/	Various features

Step 3: Map to documentation files

Use the code-to-docs mapping in references/CODE-TO-DOCS-MAPPING.md to find corresponding documentation files.

Example mappings:

• src/client/components/image.tsx → docs/01-app/03-api-reference/02-components/image.mdx
• src/server/config-shared.ts → docs/01-app/03-api-reference/05-config/

Workflow: Update Existing Documentation

Step 1: Read the current documentation

Before making changes, read the existing doc to understand:

• Current structure and sections
• Frontmatter fields in use
• Whether it uses <AppOnly> / <PagesOnly> for router-specific content

Step 2: Identify what needs updating

Common updates include:

• New props/options: Add to the props table and create a section explaining usage
• Changed behavior: Update descriptions and examples
• Deprecated features: Add deprecation notices and migration guidance
• New examples: Add code blocks following conventions

Step 3: Apply updates with confirmation

For each change:

1. Show the user what you plan to change
2. Wait for confirmation before editing
3. Apply the edit
4. Move to the next change

Step 4: Check for shared content

If the doc uses the source field pattern (common for Pages Router docs), the source file is the one to edit. Example:

# docs/02-pages/... file with shared content
---
source: app/building-your-application/optimizing/images
---

Edit the App Router source, not the Pages Router file.

Step 5: Validate changes

pnpm lint          # Check formatting
pnpm prettier-fix  # Auto-fix formatting issues

Workflow: Scaffold New Feature Documentation

Use this when adding documentation for entirely new features.

Step 1: Determine the doc type

Feature Type	Doc Location	Template
New component	docs/01-app/03-api-reference/02-components/	API Reference
New function	docs/01-app/03-api-reference/04-functions/	API Reference
New config option	docs/01-app/03-api-reference/05-config/	Config Reference
New concept/guide	docs/01-app/02-guides/	Guide
New file convention	docs/01-app/03-api-reference/03-file-conventions/	File Convention

Step 2: Create the file with proper naming

• Use kebab-case: my-new-feature.mdx
• Add numeric prefix if ordering matters: 05-my-new-feature.mdx
• Place in the correct directory based on feature type

Step 3: Use the appropriate template

API Reference Template:

---
title: Feature Name
description: Brief description of what this feature does.
---

{/* The content of this doc is shared between the app and pages router. You can use the `<PagesOnly>Content</PagesOnly>` component to add content that is specific to the Pages Router. Any shared content should not be wrapped in a component. */}

Brief introduction to the feature.

## Reference

### Props

<div style={{ overflowX: 'auto', width: '100%' }}>

| Prop                    | Example            | Type   | Status   |
| ----------------------- | ------------------ | ------ | -------- |
| [`propName`](#propname) | `propName="value"` | String | Required |

</div>

#### `propName`

Description of the prop.

\`\`\`tsx filename="app/example.tsx" switcher
// TypeScript example
\`\`\`

\`\`\`jsx filename="app/example.js" switcher
// JavaScript example
\`\`\`

Guide Template:

---
title: How to do X in Next.js
nav_title: X
description: Learn how to implement X in your Next.js application.
---

Introduction explaining why this guide is useful.

## Prerequisites

What the reader needs to know before starting.

## Step 1: First Step

Explanation and code example.

\`\`\`tsx filename="app/example.tsx" switcher
// Code example
\`\`\`

## Step 2: Second Step

Continue with more steps...

## Next Steps

Related topics to explore.

Step 4: Add related links

Update frontmatter with related documentation:

related:
  title: Next Steps
  description: Learn more about related features.
  links:
    - app/api-reference/functions/related-function
    - app/guides/related-guide

Documentation Conventions

See references/DOC-CONVENTIONS.md for complete formatting rules.

Quick Reference

Frontmatter (required):

---
title: Page Title (2-3 words)
description: One or two sentences describing the page.
---

Code blocks:

\`\`\`tsx filename="app/page.tsx" switcher
// TypeScript first
\`\`\`

\`\`\`jsx filename="app/page.js" switcher
// JavaScript second
\`\`\`

Router-specific content:

<AppOnly>Content only for App Router docs.</AppOnly>

<PagesOnly>Content only for Pages Router docs.</PagesOnly>

Notes:

> **Good to know**: Single line note.

> **Good to know**:
>
> - Multi-line note point 1
> - Multi-line note point 2

Validation Checklist

Before committing documentation changes:

• [ ] Frontmatter has title and description
• [ ] Code blocks have filename attribute
• [ ] TypeScript examples use switcher with JS variant
• [ ] Props tables are properly formatted
• [ ] Related links point to valid paths
• [ ] pnpm lint passes
• [ ] Changes render correctly (if preview available)

References

• references/DOC-CONVENTIONS.md - Complete frontmatter and formatting rules
• references/CODE-TO-DOCS-MAPPING.md - Source code to documentation mapping