From caa30ddcc0ab9808c7304c86b40e605cc175a8dd Mon Sep 17 00:00:00 2001 From: yyh <92089059+lyzno1@users.noreply.github.com> Date: Tue, 27 Jan 2026 19:54:46 +0800 Subject: [PATCH] chore: remove project skills (#31615) --- .agent/skills/component-refactoring | 1 - .agent/skills/frontend-code-review | 1 - .agent/skills/frontend-testing | 1 - .agent/skills/orpc-contract-first | 1 - .agent/skills/skill-creator | 1 - .agent/skills/vercel-react-best-practices | 1 - .agent/skills/web-design-guidelines | 1 - .agents/skills/skill-creator/SKILL.md | 355 --- .../references/output-patterns.md | 86 - .../skill-creator/references/workflows.md | 28 - .../skill-creator/scripts/init_skill.py | 300 -- .../skill-creator/scripts/package_skill.py | 110 - .../skill-creator/scripts/quick_validate.py | 97 - .../vercel-react-best-practices/AGENTS.md | 2410 ----------------- .../vercel-react-best-practices/SKILL.md | 125 - .../rules/advanced-event-handler-refs.md | 55 - .../rules/advanced-use-latest.md | 49 - 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-../../.agents/skills/web-design-guidelines \ No newline at end of file diff --git a/.agents/skills/skill-creator/SKILL.md b/.agents/skills/skill-creator/SKILL.md deleted file mode 100644 index b49da5ac68..0000000000 --- a/.agents/skills/skill-creator/SKILL.md +++ /dev/null @@ -1,355 +0,0 @@ ---- -name: skill-creator -description: Guide for creating effective skills. This skill should be used when users want to create a new skill (or update an existing skill) that extends Claude's capabilities with specialized knowledge, workflows, or tool integrations. ---- - -# Skill Creator - -This skill provides guidance for creating effective skills. - -## About Skills - -Skills are modular, self-contained packages that extend Claude's capabilities by providing -specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific -domains or tasks—they transform Claude from a general-purpose agent into a specialized agent -equipped with procedural knowledge that no model can fully possess. - -### What Skills Provide - -1. Specialized workflows - Multi-step procedures for specific domains -2. Tool integrations - Instructions for working with specific file formats or APIs -3. Domain expertise - Company-specific knowledge, schemas, business logic -4. Bundled resources - Scripts, references, and assets for complex and repetitive tasks - -## Core Principles - -### Concise is Key - -The context window is a public good. Skills share the context window with everything else Claude needs: system prompt, conversation history, other Skills' metadata, and the actual user request. - -**Default assumption: Claude is already very smart.** Only add context Claude doesn't already have. Challenge each piece of information: "Does Claude really need this explanation?" and "Does this paragraph justify its token cost?" - -Prefer concise examples over verbose explanations. - -### Set Appropriate Degrees of Freedom - -Match the level of specificity to the task's fragility and variability: - -**High freedom (text-based instructions)**: Use when multiple approaches are valid, decisions depend on context, or heuristics guide the approach. - -**Medium freedom (pseudocode or scripts with parameters)**: Use when a preferred pattern exists, some variation is acceptable, or configuration affects behavior. - -**Low freedom (specific scripts, few parameters)**: Use when operations are fragile and error-prone, consistency is critical, or a specific sequence must be followed. - -Think of Claude as exploring a path: a narrow bridge with cliffs needs specific guardrails (low freedom), while an open field allows many routes (high freedom). - -### Anatomy of a Skill - -Every skill consists of a required SKILL.md file and optional bundled resources: - -``` -skill-name/ -├── SKILL.md (required) -│ ├── YAML frontmatter metadata (required) -│ │ ├── name: (required) -│ │ └── description: (required) -│ └── Markdown instructions (required) -└── Bundled Resources (optional) - ├── scripts/ - Executable code (Python/Bash/etc.) - ├── references/ - Documentation intended to be loaded into context as needed - └── assets/ - Files used in output (templates, icons, fonts, etc.) -``` - -#### SKILL.md (required) - -Every SKILL.md consists of: - -- **Frontmatter** (YAML): Contains `name` and `description` fields. These are the only fields that Claude reads to determine when the skill gets used, thus it is very important to be clear and comprehensive in describing what the skill is, and when it should be used. -- **Body** (Markdown): Instructions and guidance for using the skill. Only loaded AFTER the skill triggers (if at all). - -#### Bundled Resources (optional) - -##### Scripts (`scripts/`) - -Executable code (Python/Bash/etc.) for tasks that require deterministic reliability or are repeatedly rewritten. - -- **When to include**: When the same code is being rewritten repeatedly or deterministic reliability is needed -- **Example**: `scripts/rotate_pdf.py` for PDF rotation tasks -- **Benefits**: Token efficient, deterministic, may be executed without loading into context -- **Note**: Scripts may still need to be read by Claude for patching or environment-specific adjustments - -##### References (`references/`) - -Documentation and reference material intended to be loaded as needed into context to inform Claude's process and thinking. - -- **When to include**: For documentation that Claude should reference while working -- **Examples**: `references/finance.md` for financial schemas, `references/mnda.md` for company NDA template, `references/policies.md` for company policies, `references/api_docs.md` for API specifications -- **Use cases**: Database schemas, API documentation, domain knowledge, company policies, detailed workflow guides -- **Benefits**: Keeps SKILL.md lean, loaded only when Claude determines it's needed -- **Best practice**: If files are large (>10k words), include grep search patterns in SKILL.md -- **Avoid duplication**: Information should live in either SKILL.md or references files, not both. Prefer references files for detailed information unless it's truly core to the skill—this keeps SKILL.md lean while making information discoverable without hogging the context window. Keep only essential procedural instructions and workflow guidance in SKILL.md; move detailed reference material, schemas, and examples to references files. - -##### Assets (`assets/`) - -Files not intended to be loaded into context, but rather used within the output Claude produces. - -- **When to include**: When the skill needs files that will be used in the final output -- **Examples**: `assets/logo.png` for brand assets, `assets/slides.pptx` for PowerPoint templates, `assets/frontend-template/` for HTML/React boilerplate, `assets/font.ttf` for typography -- **Use cases**: Templates, images, icons, boilerplate code, fonts, sample documents that get copied or modified -- **Benefits**: Separates output resources from documentation, enables Claude to use files without loading them into context - -#### What to Not Include in a Skill - -A skill should only contain essential files that directly support its functionality. Do NOT create extraneous documentation or auxiliary files, including: - -- README.md -- INSTALLATION_GUIDE.md -- QUICK_REFERENCE.md -- CHANGELOG.md -- etc. - -The skill should only contain the information needed for an AI agent to do the job at hand. It should not contain auxilary context about the process that went into creating it, setup and testing procedures, user-facing documentation, etc. Creating additional documentation files just adds clutter and confusion. - -### Progressive Disclosure Design Principle - -Skills use a three-level loading system to manage context efficiently: - -1. **Metadata (name + description)** - Always in context (~100 words) -2. **SKILL.md body** - When skill triggers (<5k words) -3. **Bundled resources** - As needed by Claude (Unlimited because scripts can be executed without reading into context window) - -#### Progressive Disclosure Patterns - -Keep SKILL.md body to the essentials and under 500 lines to minimize context bloat. Split content into separate files when approaching this limit. When splitting out content into other files, it is very important to reference them from SKILL.md and describe clearly when to read them, to ensure the reader of the skill knows they exist and when to use them. - -**Key principle:** When a skill supports multiple variations, frameworks, or options, keep only the core workflow and selection guidance in SKILL.md. Move variant-specific details (patterns, examples, configuration) into separate reference files. - -**Pattern 1: High-level guide with references** - -```markdown -# PDF Processing - -## Quick start - -Extract text with pdfplumber: -[code example] - -## Advanced features - -- **Form filling**: See [FORMS.md](FORMS.md) for complete guide -- **API reference**: See [REFERENCE.md](REFERENCE.md) for all methods -- **Examples**: See [EXAMPLES.md](EXAMPLES.md) for common patterns -``` - -Claude loads FORMS.md, REFERENCE.md, or EXAMPLES.md only when needed. - -**Pattern 2: Domain-specific organization** - -For Skills with multiple domains, organize content by domain to avoid loading irrelevant context: - -``` -bigquery-skill/ -├── SKILL.md (overview and navigation) -└── reference/ - ├── finance.md (revenue, billing metrics) - ├── sales.md (opportunities, pipeline) - ├── product.md (API usage, features) - └── marketing.md (campaigns, attribution) -``` - -When a user asks about sales metrics, Claude only reads sales.md. - -Similarly, for skills supporting multiple frameworks or variants, organize by variant: - -``` -cloud-deploy/ -├── SKILL.md (workflow + provider selection) -└── references/ - ├── aws.md (AWS deployment patterns) - ├── gcp.md (GCP deployment patterns) - └── azure.md (Azure deployment patterns) -``` - -When the user chooses AWS, Claude only reads aws.md. - -**Pattern 3: Conditional details** - -Show basic content, link to advanced content: - -```markdown -# DOCX Processing - -## Creating documents - -Use docx-js for new documents. See [DOCX-JS.md](DOCX-JS.md). - -## Editing documents - -For simple edits, modify the XML directly. - -**For tracked changes**: See [REDLINING.md](REDLINING.md) -**For OOXML details**: See [OOXML.md](OOXML.md) -``` - -Claude reads REDLINING.md or OOXML.md only when the user needs those features. - -**Important guidelines:** - -- **Avoid deeply nested references** - Keep references one level deep from SKILL.md. All reference files should link directly from SKILL.md. -- **Structure longer reference files** - For files longer than 100 lines, include a table of contents at the top so Claude can see the full scope when previewing. - -## Skill Creation Process - -Skill creation involves these steps: - -1. Understand the skill with concrete examples -2. Plan reusable skill contents (scripts, references, assets) -3. Initialize the skill (run init_skill.py) -4. Edit the skill (implement resources and write SKILL.md) -5. Package the skill (run package_skill.py) -6. Iterate based on real usage - -Follow these steps in order, skipping only if there is a clear reason why they are not applicable. - -### Step 1: Understanding the Skill with Concrete Examples - -Skip this step only when the skill's usage patterns are already clearly understood. It remains valuable even when working with an existing skill. - -To create an effective skill, clearly understand concrete examples of how the skill will be used. This understanding can come from either direct user examples or generated examples that are validated with user feedback. - -For example, when building an image-editor skill, relevant questions include: - -- "What functionality should the image-editor skill support? Editing, rotating, anything else?" -- "Can you give some examples of how this skill would be used?" -- "I can imagine users asking for things like 'Remove the red-eye from this image' or 'Rotate this image'. Are there other ways you imagine this skill being used?" -- "What would a user say that should trigger this skill?" - -To avoid overwhelming users, avoid asking too many questions in a single message. Start with the most important questions and follow up as needed for better effectiveness. - -Conclude this step when there is a clear sense of the functionality the skill should support. - -### Step 2: Planning the Reusable Skill Contents - -To turn concrete examples into an effective skill, analyze each example by: - -1. Considering how to execute on the example from scratch -2. Identifying what scripts, references, and assets would be helpful when executing these workflows repeatedly - -Example: When building a `pdf-editor` skill to handle queries like "Help me rotate this PDF," the analysis shows: - -1. Rotating a PDF requires re-writing the same code each time -2. A `scripts/rotate_pdf.py` script would be helpful to store in the skill - -Example: When designing a `frontend-webapp-builder` skill for queries like "Build me a todo app" or "Build me a dashboard to track my steps," the analysis shows: - -1. Writing a frontend webapp requires the same boilerplate HTML/React each time -2. An `assets/hello-world/` template containing the boilerplate HTML/React project files would be helpful to store in the skill - -Example: When building a `big-query` skill to handle queries like "How many users have logged in today?" the analysis shows: - -1. Querying BigQuery requires re-discovering the table schemas and relationships each time -2. A `references/schema.md` file documenting the table schemas would be helpful to store in the skill - -To establish the skill's contents, analyze each concrete example to create a list of the reusable resources to include: scripts, references, and assets. - -### Step 3: Initializing the Skill - -At this point, it is time to actually create the skill. - -Skip this step only if the skill being developed already exists, and iteration or packaging is needed. In this case, continue to the next step. - -When creating a new skill from scratch, always run the `init_skill.py` script. The script conveniently generates a new template skill directory that automatically includes everything a skill requires, making the skill creation process much more efficient and reliable. - -Usage: - -```bash -scripts/init_skill.py --path -``` - -The script: - -- Creates the skill directory at the specified path -- Generates a SKILL.md template with proper frontmatter and TODO placeholders -- Creates example resource directories: `scripts/`, `references/`, and `assets/` -- Adds example files in each directory that can be customized or deleted - -After initialization, customize or remove the generated SKILL.md and example files as needed. - -### Step 4: Edit the Skill - -When editing the (newly-generated or existing) skill, remember that the skill is being created for another instance of Claude to use. Include information that would be beneficial and non-obvious to Claude. Consider what procedural knowledge, domain-specific details, or reusable assets would help another Claude instance execute these tasks more effectively. - -#### Learn Proven Design Patterns - -Consult these helpful guides based on your skill's needs: - -- **Multi-step processes**: See references/workflows.md for sequential workflows and conditional logic -- **Specific output formats or quality standards**: See references/output-patterns.md for template and example patterns - -These files contain established best practices for effective skill design. - -#### Start with Reusable Skill Contents - -To begin implementation, start with the reusable resources identified above: `scripts/`, `references/`, and `assets/` files. Note that this step may require user input. For example, when implementing a `brand-guidelines` skill, the user may need to provide brand assets or templates to store in `assets/`, or documentation to store in `references/`. - -Added scripts must be tested by actually running them to ensure there are no bugs and that the output matches what is expected. If there are many similar scripts, only a representative sample needs to be tested to ensure confidence that they all work while balancing time to completion. - -Any example files and directories not needed for the skill should be deleted. The initialization script creates example files in `scripts/`, `references/`, and `assets/` to demonstrate structure, but most skills won't need all of them. - -#### Update SKILL.md - -**Writing Guidelines:** Always use imperative/infinitive form. - -##### Frontmatter - -Write the YAML frontmatter with `name` and `description`: - -- `name`: The skill name -- `description`: This is the primary triggering mechanism for your skill, and helps Claude understand when to use the skill. - - Include both what the Skill does and specific triggers/contexts for when to use it. - - Include all "when to use" information here - Not in the body. The body is only loaded after triggering, so "When to Use This Skill" sections in the body are not helpful to Claude. - - Example description for a `docx` skill: "Comprehensive document creation, editing, and analysis with support for tracked changes, comments, formatting preservation, and text extraction. Use when Claude needs to work with professional documents (.docx files) for: (1) Creating new documents, (2) Modifying or editing content, (3) Working with tracked changes, (4) Adding comments, or any other document tasks" - -Do not include any other fields in YAML frontmatter. - -##### Body - -Write instructions for using the skill and its bundled resources. - -### Step 5: Packaging a Skill - -Once development of the skill is complete, it must be packaged into a distributable .skill file that gets shared with the user. The packaging process automatically validates the skill first to ensure it meets all requirements: - -```bash -scripts/package_skill.py -``` - -Optional output directory specification: - -```bash -scripts/package_skill.py ./dist -``` - -The packaging script will: - -1. **Validate** the skill automatically, checking: - - - YAML frontmatter format and required fields - - Skill naming conventions and directory structure - - Description completeness and quality - - File organization and resource references - -2. **Package** the skill if validation passes, creating a .skill file named after the skill (e.g., `my-skill.skill`) that includes all files and maintains the proper directory structure for distribution. The .skill file is a zip file with a .skill extension. - -If validation fails, the script will report the errors and exit without creating a package. Fix any validation errors and run the packaging command again. - -### Step 6: Iterate - -After testing the skill, users may request improvements. Often this happens right after using the skill, with fresh context of how the skill performed. - -**Iteration workflow:** - -1. Use the skill on real tasks -2. Notice struggles or inefficiencies -3. Identify how SKILL.md or bundled resources should be updated -4. Implement changes and test again diff --git a/.agents/skills/skill-creator/references/output-patterns.md b/.agents/skills/skill-creator/references/output-patterns.md deleted file mode 100644 index 022e85fe5e..0000000000 --- a/.agents/skills/skill-creator/references/output-patterns.md +++ /dev/null @@ -1,86 +0,0 @@ -# Output Patterns - -Use these patterns when skills need to produce consistent, high-quality output. - -## Template Pattern - -Provide templates for output format. Match the level of strictness to your needs. - -**For strict requirements (like API responses or data formats):** - -```markdown -## Report structure - -ALWAYS use this exact template structure: - -# [Analysis Title] - -## Executive summary -[One-paragraph overview of key findings] - -## Key findings -- Finding 1 with supporting data -- Finding 2 with supporting data -- Finding 3 with supporting data - -## Recommendations -1. Specific actionable recommendation -2. Specific actionable recommendation -``` - -**For flexible guidance (when adaptation is useful):** - -```markdown -## Report structure - -Here is a sensible default format, but use your best judgment: - -# [Analysis Title] - -## Executive summary -[Overview] - -## Key findings -[Adapt sections based on what you discover] - -## Recommendations -[Tailor to the specific context] - -Adjust sections as needed for the specific analysis type. -``` - -## Examples Pattern - -For skills where output quality depends on seeing examples, provide input/output pairs: - -```markdown -## Commit message format - -Generate commit messages following these examples: - -**Example 1:** -Input: Added user authentication with JWT tokens -Output: -``` - -feat(auth): implement JWT-based authentication - -Add login endpoint and token validation middleware - -``` - -**Example 2:** -Input: Fixed bug where dates displayed incorrectly in reports -Output: -``` - -fix(reports): correct date formatting in timezone conversion - -Use UTC timestamps consistently across report generation - -``` - -Follow this style: type(scope): brief description, then detailed explanation. -``` - -Examples help Claude understand the desired style and level of detail more clearly than descriptions alone. diff --git a/.agents/skills/skill-creator/references/workflows.md b/.agents/skills/skill-creator/references/workflows.md deleted file mode 100644 index 54b0174078..0000000000 --- a/.agents/skills/skill-creator/references/workflows.md +++ /dev/null @@ -1,28 +0,0 @@ -# Workflow Patterns - -## Sequential Workflows - -For complex tasks, break operations into clear, sequential steps. It is often helpful to give Claude an overview of the process towards the beginning of SKILL.md: - -```markdown -Filling a PDF form involves these steps: - -1. Analyze the form (run analyze_form.py) -2. Create field mapping (edit fields.json) -3. Validate mapping (run validate_fields.py) -4. Fill the form (run fill_form.py) -5. Verify output (run verify_output.py) -``` - -## Conditional Workflows - -For tasks with branching logic, guide Claude through decision points: - -```markdown -1. Determine the modification type: - **Creating new content?** → Follow "Creation workflow" below - **Editing existing content?** → Follow "Editing workflow" below - -2. Creation workflow: [steps] -3. Editing workflow: [steps] -``` diff --git a/.agents/skills/skill-creator/scripts/init_skill.py b/.agents/skills/skill-creator/scripts/init_skill.py deleted file mode 100755 index 249fffcbbd..0000000000 --- a/.agents/skills/skill-creator/scripts/init_skill.py +++ /dev/null @@ -1,300 +0,0 @@ -#!/usr/bin/env python3 -""" -Skill Initializer - Creates a new skill from template - -Usage: - init_skill.py --path - -Examples: - init_skill.py my-new-skill --path skills/public - init_skill.py my-api-helper --path skills/private - init_skill.py custom-skill --path /custom/location -""" - -import sys -from pathlib import Path - - -SKILL_TEMPLATE = """--- -name: {skill_name} -description: [TODO: Complete and informative explanation of what the skill does and when to use it. Include WHEN to use this skill - specific scenarios, file types, or tasks that trigger it.] ---- - -# {skill_title} - -## Overview - -[TODO: 1-2 sentences explaining what this skill enables] - -## Structuring This Skill - -[TODO: Choose the structure that best fits this skill's purpose. Common patterns: - -**1. Workflow-Based** (best for sequential processes) -- Works well when there are clear step-by-step procedures -- Example: DOCX skill with "Workflow Decision Tree" → "Reading" → "Creating" → "Editing" -- Structure: ## Overview → ## Workflow Decision Tree → ## Step 1 → ## Step 2... - -**2. Task-Based** (best for tool collections) -- Works well when the skill offers different operations/capabilities -- Example: PDF skill with "Quick Start" → "Merge PDFs" → "Split PDFs" → "Extract Text" -- Structure: ## Overview → ## Quick Start → ## Task Category 1 → ## Task Category 2... - -**3. Reference/Guidelines** (best for standards or specifications) -- Works well for brand guidelines, coding standards, or requirements -- Example: Brand styling with "Brand Guidelines" → "Colors" → "Typography" → "Features" -- Structure: ## Overview → ## Guidelines → ## Specifications → ## Usage... - -**4. Capabilities-Based** (best for integrated systems) -- Works well when the skill provides multiple interrelated features -- Example: Product Management with "Core Capabilities" → numbered capability list -- Structure: ## Overview → ## Core Capabilities → ### 1. Feature → ### 2. Feature... - -Patterns can be mixed and matched as needed. Most skills combine patterns (e.g., start with task-based, add workflow for complex operations). - -Delete this entire "Structuring This Skill" section when done - it's just guidance.] - -## [TODO: Replace with the first main section based on chosen structure] - -[TODO: Add content here. See examples in existing skills: -- Code samples for technical skills -- Decision trees for complex workflows -- Concrete examples with realistic user requests -- References to scripts/templates/references as needed] - -## Resources - -This skill includes example resource directories that demonstrate how to organize different types of bundled resources: - -### scripts/ -Executable code (Python/Bash/etc.) that can be run directly to perform specific operations. - -**Examples from other skills:** -- PDF skill: `fill_fillable_fields.py`, `extract_form_field_info.py` - utilities for PDF manipulation -- DOCX skill: `document.py`, `utilities.py` - Python modules for document processing - -**Appropriate for:** Python scripts, shell scripts, or any executable code that performs automation, data processing, or specific operations. - -**Note:** Scripts may be executed without loading into context, but can still be read by Claude for patching or environment adjustments. - -### references/ -Documentation and reference material intended to be loaded into context to inform Claude's process and thinking. - -**Examples from other skills:** -- Product management: `communication.md`, `context_building.md` - detailed workflow guides -- BigQuery: API reference documentation and query examples -- Finance: Schema documentation, company policies - -**Appropriate for:** In-depth documentation, API references, database schemas, comprehensive guides, or any detailed information that Claude should reference while working. - -### assets/ -Files not intended to be loaded into context, but rather used within the output Claude produces. - -**Examples from other skills:** -- Brand styling: PowerPoint template files (.pptx), logo files -- Frontend builder: HTML/React boilerplate project directories -- Typography: Font files (.ttf, .woff2) - -**Appropriate for:** Templates, boilerplate code, document templates, images, icons, fonts, or any files meant to be copied or used in the final output. - ---- - -**Any unneeded directories can be deleted.** Not every skill requires all three types of resources. -""" - -EXAMPLE_SCRIPT = '''#!/usr/bin/env python3 -""" -Example helper script for {skill_name} - -This is a placeholder script that can be executed directly. -Replace with actual implementation or delete if not needed. - -Example real scripts from other skills: -- pdf/scripts/fill_fillable_fields.py - Fills PDF form fields -- pdf/scripts/convert_pdf_to_images.py - Converts PDF pages to images -""" - -def main(): - print("This is an example script for {skill_name}") - # TODO: Add actual script logic here - # This could be data processing, file conversion, API calls, etc. - -if __name__ == "__main__": - main() -''' - -EXAMPLE_REFERENCE = """# Reference Documentation for {skill_title} - -This is a placeholder for detailed reference documentation. -Replace with actual reference content or delete if not needed. - -Example real reference docs from other skills: -- product-management/references/communication.md - Comprehensive guide for status updates -- product-management/references/context_building.md - Deep-dive on gathering context -- bigquery/references/ - API references and query examples - -## When Reference Docs Are Useful - -Reference docs are ideal for: -- Comprehensive API documentation -- Detailed workflow guides -- Complex multi-step processes -- Information too lengthy for main SKILL.md -- Content that's only needed for specific use cases - -## Structure Suggestions - -### API Reference Example -- Overview -- Authentication -- Endpoints with examples -- Error codes -- Rate limits - -### Workflow Guide Example -- Prerequisites -- Step-by-step instructions -- Common patterns -- Troubleshooting -- Best practices -""" - -EXAMPLE_ASSET = """# Example Asset File - -This placeholder represents where asset files would be stored. -Replace with actual asset files (templates, images, fonts, etc.) or delete if not needed. - -Asset files are NOT intended to be loaded into context, but rather used within -the output Claude produces. - -Example asset files from other skills: -- Brand guidelines: logo.png, slides_template.pptx -- Frontend builder: hello-world/ directory with HTML/React boilerplate -- Typography: custom-font.ttf, font-family.woff2 -- Data: sample_data.csv, test_dataset.json - -## Common Asset Types - -- Templates: .pptx, .docx, boilerplate directories -- Images: .png, .jpg, .svg, .gif -- Fonts: .ttf, .otf, .woff, .woff2 -- Boilerplate code: Project directories, starter files -- Icons: .ico, .svg -- Data files: .csv, .json, .xml, .yaml - -Note: This is a text placeholder. Actual assets can be any file type. -""" - - -def title_case_skill_name(skill_name): - """Convert hyphenated skill name to Title Case for display.""" - return " ".join(word.capitalize() for word in skill_name.split("-")) - - -def init_skill(skill_name, path): - """ - Initialize a new skill directory with template SKILL.md. - - Args: - skill_name: Name of the skill - path: Path where the skill directory should be created - - Returns: - Path to created skill directory, or None if error - """ - # Determine skill directory path - skill_dir = Path(path).resolve() / skill_name - - # Check if directory already exists - if skill_dir.exists(): - print(f"❌ Error: Skill directory already exists: {skill_dir}") - return None - - # Create skill directory - try: - skill_dir.mkdir(parents=True, exist_ok=False) - print(f"✅ Created skill directory: {skill_dir}") - except Exception as e: - print(f"❌ Error creating directory: {e}") - return None - - # Create SKILL.md from template - skill_title = title_case_skill_name(skill_name) - skill_content = SKILL_TEMPLATE.format(skill_name=skill_name, skill_title=skill_title) - - skill_md_path = skill_dir / "SKILL.md" - try: - skill_md_path.write_text(skill_content) - print("✅ Created SKILL.md") - except Exception as e: - print(f"❌ Error creating SKILL.md: {e}") - return None - - # Create resource directories with example files - try: - # Create scripts/ directory with example script - scripts_dir = skill_dir / "scripts" - scripts_dir.mkdir(exist_ok=True) - example_script = scripts_dir / "example.py" - example_script.write_text(EXAMPLE_SCRIPT.format(skill_name=skill_name)) - example_script.chmod(0o755) - print("✅ Created scripts/example.py") - - # Create references/ directory with example reference doc - references_dir = skill_dir / "references" - references_dir.mkdir(exist_ok=True) - example_reference = references_dir / "api_reference.md" - example_reference.write_text(EXAMPLE_REFERENCE.format(skill_title=skill_title)) - print("✅ Created references/api_reference.md") - - # Create assets/ directory with example asset placeholder - assets_dir = skill_dir / "assets" - assets_dir.mkdir(exist_ok=True) - example_asset = assets_dir / "example_asset.txt" - example_asset.write_text(EXAMPLE_ASSET) - print("✅ Created assets/example_asset.txt") - except Exception as e: - print(f"❌ Error creating resource directories: {e}") - return None - - # Print next steps - print(f"\n✅ Skill '{skill_name}' initialized successfully at {skill_dir}") - print("\nNext steps:") - print("1. Edit SKILL.md to complete the TODO items and update the description") - print("2. Customize or delete the example files in scripts/, references/, and assets/") - print("3. Run the validator when ready to check the skill structure") - - return skill_dir - - -def main(): - if len(sys.argv) < 4 or sys.argv[2] != "--path": - print("Usage: init_skill.py --path ") - print("\nSkill name requirements:") - print(" - Hyphen-case identifier (e.g., 'data-analyzer')") - print(" - Lowercase letters, digits, and hyphens only") - print(" - Max 40 characters") - print(" - Must match directory name exactly") - print("\nExamples:") - print(" init_skill.py my-new-skill --path skills/public") - print(" init_skill.py my-api-helper --path skills/private") - print(" init_skill.py custom-skill --path /custom/location") - sys.exit(1) - - skill_name = sys.argv[1] - path = sys.argv[3] - - print(f"🚀 Initializing skill: {skill_name}") - print(f" Location: {path}") - print() - - result = init_skill(skill_name, path) - - if result: - sys.exit(0) - else: - sys.exit(1) - - -if __name__ == "__main__": - main() diff --git a/.agents/skills/skill-creator/scripts/package_skill.py b/.agents/skills/skill-creator/scripts/package_skill.py deleted file mode 100755 index 736b928be0..0000000000 --- a/.agents/skills/skill-creator/scripts/package_skill.py +++ /dev/null @@ -1,110 +0,0 @@ -#!/usr/bin/env python3 -""" -Skill Packager - Creates a distributable .skill file of a skill folder - -Usage: - python utils/package_skill.py [output-directory] - -Example: - python utils/package_skill.py skills/public/my-skill - python utils/package_skill.py skills/public/my-skill ./dist -""" - -import sys -import zipfile -from pathlib import Path -from quick_validate import validate_skill - - -def package_skill(skill_path, output_dir=None): - """ - Package a skill folder into a .skill file. - - Args: - skill_path: Path to the skill folder - output_dir: Optional output directory for the .skill file (defaults to current directory) - - Returns: - Path to the created .skill file, or None if error - """ - skill_path = Path(skill_path).resolve() - - # Validate skill folder exists - if not skill_path.exists(): - print(f"❌ Error: Skill folder not found: {skill_path}") - return None - - if not skill_path.is_dir(): - print(f"❌ Error: Path is not a directory: {skill_path}") - return None - - # Validate SKILL.md exists - skill_md = skill_path / "SKILL.md" - if not skill_md.exists(): - print(f"❌ Error: SKILL.md not found in {skill_path}") - return None - - # Run validation before packaging - print("🔍 Validating skill...") - valid, message = validate_skill(skill_path) - if not valid: - print(f"❌ Validation failed: {message}") - print(" Please fix the validation errors before packaging.") - return None - print(f"✅ {message}\n") - - # Determine output location - skill_name = skill_path.name - if output_dir: - output_path = Path(output_dir).resolve() - output_path.mkdir(parents=True, exist_ok=True) - else: - output_path = Path.cwd() - - skill_filename = output_path / f"{skill_name}.skill" - - # Create the .skill file (zip format) - try: - with zipfile.ZipFile(skill_filename, "w", zipfile.ZIP_DEFLATED) as zipf: - # Walk through the skill directory - for file_path in skill_path.rglob("*"): - if file_path.is_file(): - # Calculate the relative path within the zip - arcname = file_path.relative_to(skill_path.parent) - zipf.write(file_path, arcname) - print(f" Added: {arcname}") - - print(f"\n✅ Successfully packaged skill to: {skill_filename}") - return skill_filename - - except Exception as e: - print(f"❌ Error creating .skill file: {e}") - return None - - -def main(): - if len(sys.argv) < 2: - print("Usage: python utils/package_skill.py [output-directory]") - print("\nExample:") - print(" python utils/package_skill.py skills/public/my-skill") - print(" python utils/package_skill.py skills/public/my-skill ./dist") - sys.exit(1) - - skill_path = sys.argv[1] - output_dir = sys.argv[2] if len(sys.argv) > 2 else None - - print(f"📦 Packaging skill: {skill_path}") - if output_dir: - print(f" Output directory: {output_dir}") - print() - - result = package_skill(skill_path, output_dir) - - if result: - sys.exit(0) - else: - sys.exit(1) - - -if __name__ == "__main__": - main() diff --git a/.agents/skills/skill-creator/scripts/quick_validate.py b/.agents/skills/skill-creator/scripts/quick_validate.py deleted file mode 100755 index 66eb0a71bf..0000000000 --- a/.agents/skills/skill-creator/scripts/quick_validate.py +++ /dev/null @@ -1,97 +0,0 @@ -#!/usr/bin/env python3 -""" -Quick validation script for skills - minimal version -""" - -import sys -import os -import re -import yaml -from pathlib import Path - - -def validate_skill(skill_path): - """Basic validation of a skill""" - skill_path = Path(skill_path) - - # Check SKILL.md exists - skill_md = skill_path / "SKILL.md" - if not skill_md.exists(): - return False, "SKILL.md not found" - - # Read and validate frontmatter - content = skill_md.read_text() - if not content.startswith("---"): - return False, "No YAML frontmatter found" - - # Extract frontmatter - match = re.match(r"^---\n(.*?)\n---", content, re.DOTALL) - if not match: - return False, "Invalid frontmatter format" - - frontmatter_text = match.group(1) - - # Parse YAML frontmatter - try: - frontmatter = yaml.safe_load(frontmatter_text) - if not isinstance(frontmatter, dict): - return False, "Frontmatter must be a YAML dictionary" - except yaml.YAMLError as e: - return False, f"Invalid YAML in frontmatter: {e}" - - # Define allowed properties - ALLOWED_PROPERTIES = {"name", "description", "license", "allowed-tools", "metadata"} - - # Check for unexpected properties (excluding nested keys under metadata) - unexpected_keys = set(frontmatter.keys()) - ALLOWED_PROPERTIES - if unexpected_keys: - return False, ( - f"Unexpected key(s) in SKILL.md frontmatter: {', '.join(sorted(unexpected_keys))}. " - f"Allowed properties are: {', '.join(sorted(ALLOWED_PROPERTIES))}" - ) - - # Check required fields - if "name" not in frontmatter: - return False, "Missing 'name' in frontmatter" - if "description" not in frontmatter: - return False, "Missing 'description' in frontmatter" - - # Extract name for validation - name = frontmatter.get("name", "") - if not isinstance(name, str): - return False, f"Name must be a string, got {type(name).__name__}" - name = name.strip() - if name: - # Check naming convention (hyphen-case: lowercase with hyphens) - if not re.match(r"^[a-z0-9-]+$", name): - return False, f"Name '{name}' should be hyphen-case (lowercase letters, digits, and hyphens only)" - if name.startswith("-") or name.endswith("-") or "--" in name: - return False, f"Name '{name}' cannot start/end with hyphen or contain consecutive hyphens" - # Check name length (max 64 characters per spec) - if len(name) > 64: - return False, f"Name is too long ({len(name)} characters). Maximum is 64 characters." - - # Extract and validate description - description = frontmatter.get("description", "") - if not isinstance(description, str): - return False, f"Description must be a string, got {type(description).__name__}" - description = description.strip() - if description: - # Check for angle brackets - if "<" in description or ">" in description: - return False, "Description cannot contain angle brackets (< or >)" - # Check description length (max 1024 characters per spec) - if len(description) > 1024: - return False, f"Description is too long ({len(description)} characters). Maximum is 1024 characters." - - return True, "Skill is valid!" - - -if __name__ == "__main__": - if len(sys.argv) != 2: - print("Usage: python quick_validate.py ") - sys.exit(1) - - valid, message = validate_skill(sys.argv[1]) - print(message) - sys.exit(0 if valid else 1) diff --git a/.agents/skills/vercel-react-best-practices/AGENTS.md b/.agents/skills/vercel-react-best-practices/AGENTS.md deleted file mode 100644 index f9b9e99c44..0000000000 --- a/.agents/skills/vercel-react-best-practices/AGENTS.md +++ /dev/null @@ -1,2410 +0,0 @@ -# React Best Practices - -**Version 1.0.0** -Vercel Engineering -January 2026 - -> **Note:** -> This document is mainly for agents and LLMs to follow when maintaining, -> generating, or refactoring React and Next.js codebases at Vercel. Humans -> may also find it useful, but guidance here is optimized for automation -> and consistency by AI-assisted workflows. - ---- - -## Abstract - -Comprehensive performance optimization guide for React and Next.js applications, designed for AI agents and LLMs. Contains 40+ rules across 8 categories, prioritized by impact from critical (eliminating waterfalls, reducing bundle size) to incremental (advanced patterns). Each rule includes detailed explanations, real-world examples comparing incorrect vs. correct implementations, and specific impact metrics to guide automated refactoring and code generation. - ---- - -## Table of Contents - -1. [Eliminating Waterfalls](#1-eliminating-waterfalls) — **CRITICAL** - - 1.1 [Defer Await Until Needed](#11-defer-await-until-needed) - - 1.2 [Dependency-Based Parallelization](#12-dependency-based-parallelization) - - 1.3 [Prevent Waterfall Chains in API Routes](#13-prevent-waterfall-chains-in-api-routes) - - 1.4 [Promise.all() for Independent Operations](#14-promiseall-for-independent-operations) - - 1.5 [Strategic Suspense Boundaries](#15-strategic-suspense-boundaries) -2. [Bundle Size Optimization](#2-bundle-size-optimization) — **CRITICAL** - - 2.1 [Avoid Barrel File Imports](#21-avoid-barrel-file-imports) - - 2.2 [Conditional Module Loading](#22-conditional-module-loading) - - 2.3 [Defer Non-Critical Third-Party Libraries](#23-defer-non-critical-third-party-libraries) - - 2.4 [Dynamic Imports for Heavy Components](#24-dynamic-imports-for-heavy-components) - - 2.5 [Preload Based on User Intent](#25-preload-based-on-user-intent) -3. [Server-Side Performance](#3-server-side-performance) — **HIGH** - - 3.1 [Cross-Request LRU Caching](#31-cross-request-lru-caching) - - 3.2 [Minimize Serialization at RSC Boundaries](#32-minimize-serialization-at-rsc-boundaries) - - 3.3 [Parallel Data Fetching with Component Composition](#33-parallel-data-fetching-with-component-composition) - - 3.4 [Per-Request Deduplication with React.cache()](#34-per-request-deduplication-with-reactcache) - - 3.5 [Use after() for Non-Blocking Operations](#35-use-after-for-non-blocking-operations) -4. [Client-Side Data Fetching](#4-client-side-data-fetching) — **MEDIUM-HIGH** - - 4.1 [Deduplicate Global Event Listeners](#41-deduplicate-global-event-listeners) - - 4.2 [Use Passive Event Listeners for Scrolling Performance](#42-use-passive-event-listeners-for-scrolling-performance) - - 4.3 [Use SWR for Automatic Deduplication](#43-use-swr-for-automatic-deduplication) - - 4.4 [Version and Minimize localStorage Data](#44-version-and-minimize-localstorage-data) -5. [Re-render Optimization](#5-re-render-optimization) — **MEDIUM** - - 5.1 [Defer State Reads to Usage Point](#51-defer-state-reads-to-usage-point) - - 5.2 [Extract to Memoized Components](#52-extract-to-memoized-components) - - 5.3 [Narrow Effect Dependencies](#53-narrow-effect-dependencies) - - 5.4 [Subscribe to Derived State](#54-subscribe-to-derived-state) - - 5.5 [Use Functional setState Updates](#55-use-functional-setstate-updates) - - 5.6 [Use Lazy State Initialization](#56-use-lazy-state-initialization) - - 5.7 [Use Transitions for Non-Urgent Updates](#57-use-transitions-for-non-urgent-updates) -6. [Rendering Performance](#6-rendering-performance) — **MEDIUM** - - 6.1 [Animate SVG Wrapper Instead of SVG Element](#61-animate-svg-wrapper-instead-of-svg-element) - - 6.2 [CSS content-visibility for Long Lists](#62-css-content-visibility-for-long-lists) - - 6.3 [Hoist Static JSX Elements](#63-hoist-static-jsx-elements) - - 6.4 [Optimize SVG Precision](#64-optimize-svg-precision) - - 6.5 [Prevent Hydration Mismatch Without Flickering](#65-prevent-hydration-mismatch-without-flickering) - - 6.6 [Use Activity Component for Show/Hide](#66-use-activity-component-for-showhide) - - 6.7 [Use Explicit Conditional Rendering](#67-use-explicit-conditional-rendering) -7. [JavaScript Performance](#7-javascript-performance) — **LOW-MEDIUM** - - 7.1 [Batch DOM CSS Changes](#71-batch-dom-css-changes) - - 7.2 [Build Index Maps for Repeated Lookups](#72-build-index-maps-for-repeated-lookups) - - 7.3 [Cache Property Access in Loops](#73-cache-property-access-in-loops) - - 7.4 [Cache Repeated Function Calls](#74-cache-repeated-function-calls) - - 7.5 [Cache Storage API Calls](#75-cache-storage-api-calls) - - 7.6 [Combine Multiple Array Iterations](#76-combine-multiple-array-iterations) - - 7.7 [Early Length Check for Array Comparisons](#77-early-length-check-for-array-comparisons) - - 7.8 [Early Return from Functions](#78-early-return-from-functions) - - 7.9 [Hoist RegExp Creation](#79-hoist-regexp-creation) - - 7.10 [Use Loop for Min/Max Instead of Sort](#710-use-loop-for-minmax-instead-of-sort) - - 7.11 [Use Set/Map for O(1) Lookups](#711-use-setmap-for-o1-lookups) - - 7.12 [Use toSorted() Instead of sort() for Immutability](#712-use-tosorted-instead-of-sort-for-immutability) -8. [Advanced Patterns](#8-advanced-patterns) — **LOW** - - 8.1 [Store Event Handlers in Refs](#81-store-event-handlers-in-refs) - - 8.2 [useLatest for Stable Callback Refs](#82-uselatest-for-stable-callback-refs) - ---- - -## 1. Eliminating Waterfalls - -**Impact: CRITICAL** - -Waterfalls are the #1 performance killer. Each sequential await adds full network latency. Eliminating them yields the largest gains. - -### 1.1 Defer Await Until Needed - -**Impact: HIGH (avoids blocking unused code paths)** - -Move `await` operations into the branches where they're actually used to avoid blocking code paths that don't need them. - -**Incorrect: blocks both branches** - -```typescript -async function handleRequest(userId: string, skipProcessing: boolean) { - const userData = await fetchUserData(userId) - - if (skipProcessing) { - // Returns immediately but still waited for userData - return { skipped: true } - } - - // Only this branch uses userData - return processUserData(userData) -} -``` - -**Correct: only blocks when needed** - -```typescript -async function handleRequest(userId: string, skipProcessing: boolean) { - if (skipProcessing) { - // Returns immediately without waiting - return { skipped: true } - } - - // Fetch only when needed - const userData = await fetchUserData(userId) - return processUserData(userData) -} -``` - -**Another example: early return optimization** - -```typescript -// Incorrect: always fetches permissions -async function updateResource(resourceId: string, userId: string) { - const permissions = await fetchPermissions(userId) - const resource = await getResource(resourceId) - - if (!resource) { - return { error: 'Not found' } - } - - if (!permissions.canEdit) { - return { error: 'Forbidden' } - } - - return await updateResourceData(resource, permissions) -} - -// Correct: fetches only when needed -async function updateResource(resourceId: string, userId: string) { - const resource = await getResource(resourceId) - - if (!resource) { - return { error: 'Not found' } - } - - const permissions = await fetchPermissions(userId) - - if (!permissions.canEdit) { - return { error: 'Forbidden' } - } - - return await updateResourceData(resource, permissions) -} -``` - -This optimization is especially valuable when the skipped branch is frequently taken, or when the deferred operation is expensive. - -### 1.2 Dependency-Based Parallelization - -**Impact: CRITICAL (2-10× improvement)** - -For operations with partial dependencies, use `better-all` to maximize parallelism. It automatically starts each task at the earliest possible moment. - -**Incorrect: profile waits for config unnecessarily** - -```typescript -const [user, config] = await Promise.all([ - fetchUser(), - fetchConfig() -]) -const profile = await fetchProfile(user.id) -``` - -**Correct: config and profile run in parallel** - -```typescript -import { all } from 'better-all' - -const { user, config, profile } = await all({ - async user() { return fetchUser() }, - async config() { return fetchConfig() }, - async profile() { - return fetchProfile((await this.$.user).id) - } -}) -``` - -Reference: [https://github.com/shuding/better-all](https://github.com/shuding/better-all) - -### 1.3 Prevent Waterfall Chains in API Routes - -**Impact: CRITICAL (2-10× improvement)** - -In API routes and Server Actions, start independent operations immediately, even if you don't await them yet. - -**Incorrect: config waits for auth, data waits for both** - -```typescript -export async function GET(request: Request) { - const session = await auth() - const config = await fetchConfig() - const data = await fetchData(session.user.id) - return Response.json({ data, config }) -} -``` - -**Correct: auth and config start immediately** - -```typescript -export async function GET(request: Request) { - const sessionPromise = auth() - const configPromise = fetchConfig() - const session = await sessionPromise - const [config, data] = await Promise.all([ - configPromise, - fetchData(session.user.id) - ]) - return Response.json({ data, config }) -} -``` - -For operations with more complex dependency chains, use `better-all` to automatically maximize parallelism (see Dependency-Based Parallelization). - -### 1.4 Promise.all() for Independent Operations - -**Impact: CRITICAL (2-10× improvement)** - -When async operations have no interdependencies, execute them concurrently using `Promise.all()`. - -**Incorrect: sequential execution, 3 round trips** - -```typescript -const user = await fetchUser() -const posts = await fetchPosts() -const comments = await fetchComments() -``` - -**Correct: parallel execution, 1 round trip** - -```typescript -const [user, posts, comments] = await Promise.all([ - fetchUser(), - fetchPosts(), - fetchComments() -]) -``` - -### 1.5 Strategic Suspense Boundaries - -**Impact: HIGH (faster initial paint)** - -Instead of awaiting data in async components before returning JSX, use Suspense boundaries to show the wrapper UI faster while data loads. - -**Incorrect: wrapper blocked by data fetching** - -```tsx -async function Page() { - const data = await fetchData() // Blocks entire page - - return ( -
-
Sidebar
-
Header
-
- -
-
Footer
-
- ) -} -``` - -The entire layout waits for data even though only the middle section needs it. - -**Correct: wrapper shows immediately, data streams in** - -```tsx -function Page() { - return ( -
-
Sidebar
-
Header
-
- }> - - -
-
Footer
-
- ) -} - -async function DataDisplay() { - const data = await fetchData() // Only blocks this component - return
{data.content}
-} -``` - -Sidebar, Header, and Footer render immediately. Only DataDisplay waits for data. - -**Alternative: share promise across components** - -```tsx -function Page() { - // Start fetch immediately, but don't await - const dataPromise = fetchData() - - return ( -
-
Sidebar
-
Header
- }> - - - -
Footer
-
- ) -} - -function DataDisplay({ dataPromise }: { dataPromise: Promise }) { - const data = use(dataPromise) // Unwraps the promise - return
{data.content}
-} - -function DataSummary({ dataPromise }: { dataPromise: Promise }) { - const data = use(dataPromise) // Reuses the same promise - return
{data.summary}
-} -``` - -Both components share the same promise, so only one fetch occurs. Layout renders immediately while both components wait together. - -**When NOT to use this pattern:** - -- Critical data needed for layout decisions (affects positioning) - -- SEO-critical content above the fold - -- Small, fast queries where suspense overhead isn't worth it - -- When you want to avoid layout shift (loading → content jump) - -**Trade-off:** Faster initial paint vs potential layout shift. Choose based on your UX priorities. - ---- - -## 2. Bundle Size Optimization - -**Impact: CRITICAL** - -Reducing initial bundle size improves Time to Interactive and Largest Contentful Paint. - -### 2.1 Avoid Barrel File Imports - -**Impact: CRITICAL (200-800ms import cost, slow builds)** - -Import directly from source files instead of barrel files to avoid loading thousands of unused modules. **Barrel files** are entry points that re-export multiple modules (e.g., `index.js` that does `export * from './module'`). - -Popular icon and component libraries can have **up to 10,000 re-exports** in their entry file. For many React packages, **it takes 200-800ms just to import them**, affecting both development speed and production cold starts. - -**Why tree-shaking doesn't help:** When a library is marked as external (not bundled), the bundler can't optimize it. If you bundle it to enable tree-shaking, builds become substantially slower analyzing the entire module graph. - -**Incorrect: imports entire library** - -```tsx -import { Check, X, Menu } from 'lucide-react' -// Loads 1,583 modules, takes ~2.8s extra in dev -// Runtime cost: 200-800ms on every cold start - -import { Button, TextField } from '@mui/material' -// Loads 2,225 modules, takes ~4.2s extra in dev -``` - -**Correct: imports only what you need** - -```tsx -import Check from 'lucide-react/dist/esm/icons/check' -import X from 'lucide-react/dist/esm/icons/x' -import Menu from 'lucide-react/dist/esm/icons/menu' -// Loads only 3 modules (~2KB vs ~1MB) - -import Button from '@mui/material/Button' -import TextField from '@mui/material/TextField' -// Loads only what you use -``` - -**Alternative: Next.js 13.5+** - -```js -// next.config.js - use optimizePackageImports -module.exports = { - experimental: { - optimizePackageImports: ['lucide-react', '@mui/material'] - } -} - -// Then you can keep the ergonomic barrel imports: -import { Check, X, Menu } from 'lucide-react' -// Automatically transformed to direct imports at build time -``` - -Direct imports provide 15-70% faster dev boot, 28% faster builds, 40% faster cold starts, and significantly faster HMR. - -Libraries commonly affected: `lucide-react`, `@mui/material`, `@mui/icons-material`, `@tabler/icons-react`, `react-icons`, `@headlessui/react`, `@radix-ui/react-*`, `lodash`, `ramda`, `date-fns`, `rxjs`, `react-use`. - -Reference: [https://vercel.com/blog/how-we-optimized-package-imports-in-next-js](https://vercel.com/blog/how-we-optimized-package-imports-in-next-js) - -### 2.2 Conditional Module Loading - -**Impact: HIGH (loads large data only when needed)** - -Load large data or modules only when a feature is activated. - -**Example: lazy-load animation frames** - -```tsx -function AnimationPlayer({ enabled, setEnabled }: { enabled: boolean; setEnabled: React.Dispatch> }) { - const [frames, setFrames] = useState(null) - - useEffect(() => { - if (enabled && !frames && typeof window !== 'undefined') { - import('./animation-frames.js') - .then(mod => setFrames(mod.frames)) - .catch(() => setEnabled(false)) - } - }, [enabled, frames, setEnabled]) - - if (!frames) return - return -} -``` - -The `typeof window !== 'undefined'` check prevents bundling this module for SSR, optimizing server bundle size and build speed. - -### 2.3 Defer Non-Critical Third-Party Libraries - -**Impact: MEDIUM (loads after hydration)** - -Analytics, logging, and error tracking don't block user interaction. Load them after hydration. - -**Incorrect: blocks initial bundle** - -```tsx -import { Analytics } from '@vercel/analytics/react' - -export default function RootLayout({ children }) { - return ( - - - {children} - - - - ) -} -``` - -**Correct: loads after hydration** - -```tsx -import dynamic from 'next/dynamic' - -const Analytics = dynamic( - () => import('@vercel/analytics/react').then(m => m.Analytics), - { ssr: false } -) - -export default function RootLayout({ children }) { - return ( - - - {children} - - - - ) -} -``` - -### 2.4 Dynamic Imports for Heavy Components - -**Impact: CRITICAL (directly affects TTI and LCP)** - -Use `next/dynamic` to lazy-load large components not needed on initial render. - -**Incorrect: Monaco bundles with main chunk ~300KB** - -```tsx -import { MonacoEditor } from './monaco-editor' - -function CodePanel({ code }: { code: string }) { - return -} -``` - -**Correct: Monaco loads on demand** - -```tsx -import dynamic from 'next/dynamic' - -const MonacoEditor = dynamic( - () => import('./monaco-editor').then(m => m.MonacoEditor), - { ssr: false } -) - -function CodePanel({ code }: { code: string }) { - return -} -``` - -### 2.5 Preload Based on User Intent - -**Impact: MEDIUM (reduces perceived latency)** - -Preload heavy bundles before they're needed to reduce perceived latency. - -**Example: preload on hover/focus** - -```tsx -function EditorButton({ onClick }: { onClick: () => void }) { - const preload = () => { - if (typeof window !== 'undefined') { - void import('./monaco-editor') - } - } - - return ( - - ) -} -``` - -**Example: preload when feature flag is enabled** - -```tsx -function FlagsProvider({ children, flags }: Props) { - useEffect(() => { - if (flags.editorEnabled && typeof window !== 'undefined') { - void import('./monaco-editor').then(mod => mod.init()) - } - }, [flags.editorEnabled]) - - return - {children} - -} -``` - -The `typeof window !== 'undefined'` check prevents bundling preloaded modules for SSR, optimizing server bundle size and build speed. - ---- - -## 3. Server-Side Performance - -**Impact: HIGH** - -Optimizing server-side rendering and data fetching eliminates server-side waterfalls and reduces response times. - -### 3.1 Cross-Request LRU Caching - -**Impact: HIGH (caches across requests)** - -`React.cache()` only works within one request. For data shared across sequential requests (user clicks button A then button B), use an LRU cache. - -**Implementation:** - -```typescript -import { LRUCache } from 'lru-cache' - -const cache = new LRUCache({ - max: 1000, - ttl: 5 * 60 * 1000 // 5 minutes -}) - -export async function getUser(id: string) { - const cached = cache.get(id) - if (cached) return cached - - const user = await db.user.findUnique({ where: { id } }) - cache.set(id, user) - return user -} - -// Request 1: DB query, result cached -// Request 2: cache hit, no DB query -``` - -Use when sequential user actions hit multiple endpoints needing the same data within seconds. - -**With Vercel's [Fluid Compute](https://vercel.com/docs/fluid-compute):** LRU caching is especially effective because multiple concurrent requests can share the same function instance and cache. This means the cache persists across requests without needing external storage like Redis. - -**In traditional serverless:** Each invocation runs in isolation, so consider Redis for cross-process caching. - -Reference: [https://github.com/isaacs/node-lru-cache](https://github.com/isaacs/node-lru-cache) - -### 3.2 Minimize Serialization at RSC Boundaries - -**Impact: HIGH (reduces data transfer size)** - -The React Server/Client boundary serializes all object properties into strings and embeds them in the HTML response and subsequent RSC requests. This serialized data directly impacts page weight and load time, so **size matters a lot**. Only pass fields that the client actually uses. - -**Incorrect: serializes all 50 fields** - -```tsx -async function Page() { - const user = await fetchUser() // 50 fields - return -} - -'use client' -function Profile({ user }: { user: User }) { - return
{user.name}
// uses 1 field -} -``` - -**Correct: serializes only 1 field** - -```tsx -async function Page() { - const user = await fetchUser() - return -} - -'use client' -function Profile({ name }: { name: string }) { - return
{name}
-} -``` - -### 3.3 Parallel Data Fetching with Component Composition - -**Impact: CRITICAL (eliminates server-side waterfalls)** - -React Server Components execute sequentially within a tree. Restructure with composition to parallelize data fetching. - -**Incorrect: Sidebar waits for Page's fetch to complete** - -```tsx -export default async function Page() { - const header = await fetchHeader() - return ( -
-
{header}
- -
- ) -} - -async function Sidebar() { - const items = await fetchSidebarItems() - return -} -``` - -**Correct: both fetch simultaneously** - -```tsx -async function Header() { - const data = await fetchHeader() - return
{data}
-} - -async function Sidebar() { - const items = await fetchSidebarItems() - return -} - -export default function Page() { - return ( -
-
- -
- ) -} -``` - -**Alternative with children prop:** - -```tsx -async function Header() { - const data = await fetchHeader() - return
{data}
-} - -async function Sidebar() { - const items = await fetchSidebarItems() - return -} - -function Layout({ children }: { children: ReactNode }) { - return ( -
-
- {children} -
- ) -} - -export default function Page() { - return ( - - - - ) -} -``` - -### 3.4 Per-Request Deduplication with React.cache() - -**Impact: MEDIUM (deduplicates within request)** - -Use `React.cache()` for server-side request deduplication. Authentication and database queries benefit most. - -**Usage:** - -```typescript -import { cache } from 'react' - -export const getCurrentUser = cache(async () => { - const session = await auth() - if (!session?.user?.id) return null - return await db.user.findUnique({ - where: { id: session.user.id } - }) -}) -``` - -Within a single request, multiple calls to `getCurrentUser()` execute the query only once. - -**Avoid inline objects as arguments:** - -`React.cache()` uses shallow equality (`Object.is`) to determine cache hits. Inline objects create new references each call, preventing cache hits. - -**Incorrect: always cache miss** - -```typescript -const getUser = cache(async (params: { uid: number }) => { - return await db.user.findUnique({ where: { id: params.uid } }) -}) - -// Each call creates new object, never hits cache -getUser({ uid: 1 }) -getUser({ uid: 1 }) // Cache miss, runs query again -``` - -**Correct: cache hit** - -```typescript -const params = { uid: 1 } -getUser(params) // Query runs -getUser(params) // Cache hit (same reference) -``` - -If you must pass objects, pass the same reference: - -**Next.js-Specific Note:** - -In Next.js, the `fetch` API is automatically extended with request memoization. Requests with the same URL and options are automatically deduplicated within a single request, so you don't need `React.cache()` for `fetch` calls. However, `React.cache()` is still essential for other async tasks: - -- Database queries (Prisma, Drizzle, etc.) - -- Heavy computations - -- Authentication checks - -- File system operations - -- Any non-fetch async work - -Use `React.cache()` to deduplicate these operations across your component tree. - -Reference: [https://react.dev/reference/react/cache](https://react.dev/reference/react/cache) - -### 3.5 Use after() for Non-Blocking Operations - -**Impact: MEDIUM (faster response times)** - -Use Next.js's `after()` to schedule work that should execute after a response is sent. This prevents logging, analytics, and other side effects from blocking the response. - -**Incorrect: blocks response** - -```tsx -import { logUserAction } from '@/app/utils' - -export async function POST(request: Request) { - // Perform mutation - await updateDatabase(request) - - // Logging blocks the response - const userAgent = request.headers.get('user-agent') || 'unknown' - await logUserAction({ userAgent }) - - return new Response(JSON.stringify({ status: 'success' }), { - status: 200, - headers: { 'Content-Type': 'application/json' } - }) -} -``` - -**Correct: non-blocking** - -```tsx -import { after } from 'next/server' -import { headers, cookies } from 'next/headers' -import { logUserAction } from '@/app/utils' - -export async function POST(request: Request) { - // Perform mutation - await updateDatabase(request) - - // Log after response is sent - after(async () => { - const userAgent = (await headers()).get('user-agent') || 'unknown' - const sessionCookie = (await cookies()).get('session-id')?.value || 'anonymous' - - logUserAction({ sessionCookie, userAgent }) - }) - - return new Response(JSON.stringify({ status: 'success' }), { - status: 200, - headers: { 'Content-Type': 'application/json' } - }) -} -``` - -The response is sent immediately while logging happens in the background. - -**Common use cases:** - -- Analytics tracking - -- Audit logging - -- Sending notifications - -- Cache invalidation - -- Cleanup tasks - -**Important notes:** - -- `after()` runs even if the response fails or redirects - -- Works in Server Actions, Route Handlers, and Server Components - -Reference: [https://nextjs.org/docs/app/api-reference/functions/after](https://nextjs.org/docs/app/api-reference/functions/after) - ---- - -## 4. Client-Side Data Fetching - -**Impact: MEDIUM-HIGH** - -Automatic deduplication and efficient data fetching patterns reduce redundant network requests. - -### 4.1 Deduplicate Global Event Listeners - -**Impact: LOW (single listener for N components)** - -Use `useSWRSubscription()` to share global event listeners across component instances. - -**Incorrect: N instances = N listeners** - -```tsx -function useKeyboardShortcut(key: string, callback: () => void) { - useEffect(() => { - const handler = (e: KeyboardEvent) => { - if (e.metaKey && e.key === key) { - callback() - } - } - window.addEventListener('keydown', handler) - return () => window.removeEventListener('keydown', handler) - }, [key, callback]) -} -``` - -When using the `useKeyboardShortcut` hook multiple times, each instance will register a new listener. - -**Correct: N instances = 1 listener** - -```tsx -import useSWRSubscription from 'swr/subscription' - -// Module-level Map to track callbacks per key -const keyCallbacks = new Map void>>() - -function useKeyboardShortcut(key: string, callback: () => void) { - // Register this callback in the Map - useEffect(() => { - if (!keyCallbacks.has(key)) { - keyCallbacks.set(key, new Set()) - } - keyCallbacks.get(key)!.add(callback) - - return () => { - const set = keyCallbacks.get(key) - if (set) { - set.delete(callback) - if (set.size === 0) { - keyCallbacks.delete(key) - } - } - } - }, [key, callback]) - - useSWRSubscription('global-keydown', () => { - const handler = (e: KeyboardEvent) => { - if (e.metaKey && keyCallbacks.has(e.key)) { - keyCallbacks.get(e.key)!.forEach(cb => cb()) - } - } - window.addEventListener('keydown', handler) - return () => window.removeEventListener('keydown', handler) - }) -} - -function Profile() { - // Multiple shortcuts will share the same listener - useKeyboardShortcut('p', () => { /* ... */ }) - useKeyboardShortcut('k', () => { /* ... */ }) - // ... -} -``` - -### 4.2 Use Passive Event Listeners for Scrolling Performance - -**Impact: MEDIUM (eliminates scroll delay caused by event listeners)** - -Add `{ passive: true }` to touch and wheel event listeners to enable immediate scrolling. Browsers normally wait for listeners to finish to check if `preventDefault()` is called, causing scroll delay. - -**Incorrect:** - -```typescript -useEffect(() => { - const handleTouch = (e: TouchEvent) => console.log(e.touches[0].clientX) - const handleWheel = (e: WheelEvent) => console.log(e.deltaY) - - document.addEventListener('touchstart', handleTouch) - document.addEventListener('wheel', handleWheel) - - return () => { - document.removeEventListener('touchstart', handleTouch) - document.removeEventListener('wheel', handleWheel) - } -}, []) -``` - -**Correct:** - -```typescript -useEffect(() => { - const handleTouch = (e: TouchEvent) => console.log(e.touches[0].clientX) - const handleWheel = (e: WheelEvent) => console.log(e.deltaY) - - document.addEventListener('touchstart', handleTouch, { passive: true }) - document.addEventListener('wheel', handleWheel, { passive: true }) - - return () => { - document.removeEventListener('touchstart', handleTouch) - document.removeEventListener('wheel', handleWheel) - } -}, []) -``` - -**Use passive when:** tracking/analytics, logging, any listener that doesn't call `preventDefault()`. - -**Don't use passive when:** implementing custom swipe gestures, custom zoom controls, or any listener that needs `preventDefault()`. - -### 4.3 Use SWR for Automatic Deduplication - -**Impact: MEDIUM-HIGH (automatic deduplication)** - -SWR enables request deduplication, caching, and revalidation across component instances. - -**Incorrect: no deduplication, each instance fetches** - -```tsx -function UserList() { - const [users, setUsers] = useState([]) - useEffect(() => { - fetch('/api/users') - .then(r => r.json()) - .then(setUsers) - }, []) -} -``` - -**Correct: multiple instances share one request** - -```tsx -import useSWR from 'swr' - -function UserList() { - const { data: users } = useSWR('/api/users', fetcher) -} -``` - -**For immutable data:** - -```tsx -import { useImmutableSWR } from '@/lib/swr' - -function StaticContent() { - const { data } = useImmutableSWR('/api/config', fetcher) -} -``` - -**For mutations:** - -```tsx -import { useSWRMutation } from 'swr/mutation' - -function UpdateButton() { - const { trigger } = useSWRMutation('/api/user', updateUser) - return -} -``` - -Reference: [https://swr.vercel.app](https://swr.vercel.app) - -### 4.4 Version and Minimize localStorage Data - -**Impact: MEDIUM (prevents schema conflicts, reduces storage size)** - -Add version prefix to keys and store only needed fields. Prevents schema conflicts and accidental storage of sensitive data. - -**Incorrect:** - -```typescript -// No version, stores everything, no error handling -localStorage.setItem('userConfig', JSON.stringify(fullUserObject)) -const data = localStorage.getItem('userConfig') -``` - -**Correct:** - -```typescript -const VERSION = 'v2' - -function saveConfig(config: { theme: string; language: string }) { - try { - localStorage.setItem(`userConfig:${VERSION}`, JSON.stringify(config)) - } catch { - // Throws in incognito/private browsing, quota exceeded, or disabled - } -} - -function loadConfig() { - try { - const data = localStorage.getItem(`userConfig:${VERSION}`) - return data ? JSON.parse(data) : null - } catch { - return null - } -} - -// Migration from v1 to v2 -function migrate() { - try { - const v1 = localStorage.getItem('userConfig:v1') - if (v1) { - const old = JSON.parse(v1) - saveConfig({ theme: old.darkMode ? 'dark' : 'light', language: old.lang }) - localStorage.removeItem('userConfig:v1') - } - } catch {} -} -``` - -**Store minimal fields from server responses:** - -```typescript -// User object has 20+ fields, only store what UI needs -function cachePrefs(user: FullUser) { - try { - localStorage.setItem('prefs:v1', JSON.stringify({ - theme: user.preferences.theme, - notifications: user.preferences.notifications - })) - } catch {} -} -``` - -**Always wrap in try-catch:** `getItem()` and `setItem()` throw in incognito/private browsing (Safari, Firefox), when quota exceeded, or when disabled. - -**Benefits:** Schema evolution via versioning, reduced storage size, prevents storing tokens/PII/internal flags. - ---- - -## 5. Re-render Optimization - -**Impact: MEDIUM** - -Reducing unnecessary re-renders minimizes wasted computation and improves UI responsiveness. - -### 5.1 Defer State Reads to Usage Point - -**Impact: MEDIUM (avoids unnecessary subscriptions)** - -Don't subscribe to dynamic state (searchParams, localStorage) if you only read it inside callbacks. - -**Incorrect: subscribes to all searchParams changes** - -```tsx -function ShareButton({ chatId }: { chatId: string }) { - const searchParams = useSearchParams() - - const handleShare = () => { - const ref = searchParams.get('ref') - shareChat(chatId, { ref }) - } - - return -} -``` - -**Correct: reads on demand, no subscription** - -```tsx -function ShareButton({ chatId }: { chatId: string }) { - const handleShare = () => { - const params = new URLSearchParams(window.location.search) - const ref = params.get('ref') - shareChat(chatId, { ref }) - } - - return -} -``` - -### 5.2 Extract to Memoized Components - -**Impact: MEDIUM (enables early returns)** - -Extract expensive work into memoized components to enable early returns before computation. - -**Incorrect: computes avatar even when loading** - -```tsx -function Profile({ user, loading }: Props) { - const avatar = useMemo(() => { - const id = computeAvatarId(user) - return - }, [user]) - - if (loading) return - return
{avatar}
-} -``` - -**Correct: skips computation when loading** - -```tsx -const UserAvatar = memo(function UserAvatar({ user }: { user: User }) { - const id = useMemo(() => computeAvatarId(user), [user]) - return -}) - -function Profile({ user, loading }: Props) { - if (loading) return - return ( -
- -
- ) -} -``` - -**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, manual memoization with `memo()` and `useMemo()` is not necessary. The compiler automatically optimizes re-renders. - -### 5.3 Narrow Effect Dependencies - -**Impact: LOW (minimizes effect re-runs)** - -Specify primitive dependencies instead of objects to minimize effect re-runs. - -**Incorrect: re-runs on any user field change** - -```tsx -useEffect(() => { - console.log(user.id) -}, [user]) -``` - -**Correct: re-runs only when id changes** - -```tsx -useEffect(() => { - console.log(user.id) -}, [user.id]) -``` - -**For derived state, compute outside effect:** - -```tsx -// Incorrect: runs on width=767, 766, 765... -useEffect(() => { - if (width < 768) { - enableMobileMode() - } -}, [width]) - -// Correct: runs only on boolean transition -const isMobile = width < 768 -useEffect(() => { - if (isMobile) { - enableMobileMode() - } -}, [isMobile]) -``` - -### 5.4 Subscribe to Derived State - -**Impact: MEDIUM (reduces re-render frequency)** - -Subscribe to derived boolean state instead of continuous values to reduce re-render frequency. - -**Incorrect: re-renders on every pixel change** - -```tsx -function Sidebar() { - const width = useWindowWidth() // updates continuously - const isMobile = width < 768 - return