Obsidian Plugin Development - Agent Skill

A comprehensive agent skill for developing high-quality Obsidian plugins that follow best practices, pass code review, and adhere to official submission guidelines.

Overview

This skill provides your coding agent with deep knowledge of Obsidian plugin development standards, including:

• All 33 ESLint rules from eslint-plugin-obsidianmd v0.2.3
• Official Plugin Guidelines from Obsidian documentation
• Submission requirements for the community plugins directory
• Memory management and lifecycle best practices
• Security guidelines and XSS prevention
• Platform compatibility (including iOS considerations)
• Network request best practices (requestUrl vs fetch)

Prerequisites

• A coding agent supporting the Agent Skills standard (Claude Code, OpenAI Codex, or Windsurf)
• An Obsidian plugin project (or starting a new one)

Installation

Quick Install

npx skills add https://github.com/gapmiss/obsidian-plugin-skill --skill obsidian

Setup

Option 1: Installer Script (Recommended)

1. Clone this repository:

   git clone https://github.com/gapmiss/obsidian-plugin-skill.git
   cd obsidian-plugin-skill
   

2. Run the installer:

   ./install-skill.sh
   

3. Select your provider(s):

   • All providers — installs to both .agents/skills/ and .claude/skills/
   • Claude Code — installs to .claude/skills/ with slash commands
   • Codex (OpenAI) — installs to .agents/skills/
   • Windsurf — installs to .agents/skills/

4. Choose installation target (current directory or custom path)

Option 2: Manual Install

git clone https://github.com/gapmiss/obsidian-plugin-skill.git
cd obsidian-plugin-skill

# Copy skill
mkdir -p your-project/.claude/skills/obsidian
cp -r .agents/skills/obsidian/* your-project/.claude/skills/obsidian/

# Copy slash commands
mkdir -p your-project/.claude/commands
cp .claude/commands/obsidian.md your-project/.claude/commands/
cp .claude/commands/create-plugin.md your-project/.claude/commands/

git clone https://github.com/gapmiss/obsidian-plugin-skill.git
cd obsidian-plugin-skill

# Copy skill
mkdir -p your-project/.agents/skills/obsidian
cp -r .agents/skills/obsidian/* your-project/.agents/skills/obsidian/

Option 3: Use as Standalone

Just open this directory with your coding agent — no installation needed!

Skill Structure

The skill uses progressive disclosure for optimal performance:

.agents/skills/obsidian/
├── SKILL.md                          # Main overview (263 lines)
└── reference/                        # Detailed documentation
    ├── memory-management.md          # Lifecycle & cleanup patterns
    ├── type-safety.md                # Type narrowing & safety
    ├── ui-ux.md                      # UI standards & commands
    ├── file-operations.md            # Vault & file API
    ├── css-styling.md                # Theming & styling
    ├── accessibility.md              # A11y requirements (MANDATORY)
    ├── code-quality.md               # Best practices & security
    └── submission.md                 # Publishing guidelines

SKILL.md provides a concise overview with the top 20 critical rules, while reference files contain comprehensive details on specific topics.

Quick Start: Creating a New Plugin

Interactive Boilerplate Generator

The fastest way to start a new Obsidian plugin with all best practices built-in:

node /path/to/obsidian-plugin-skill/tools/create-plugin.js

Features:

• Generates clean TypeScript boilerplate with no sample code
• Creates src/ directory structure with main.ts and settings.ts
• Validates plugin metadata in real-time against Obsidian's submission bot rules
• Prompts for target directory to avoid overwriting existing files
• Detects existing projects and only adds missing files
• All generated code follows the skill's best practices automatically

What it creates:

your-plugin/
├── src/
│   ├── main.ts           # Plugin class with settings integration
│   └── settings.ts       # Settings interface, defaults, and tab
├── manifest.json         # Validated plugin metadata
├── styles.css           # CSS with Obsidian variables
├── tsconfig.json        # TypeScript configuration
├── package.json         # Dependencies
├── esbuild.config.mjs   # Build configuration
├── version-bump.mjs     # Version management script
├── versions.json        # Version tracking
├── .gitignore          # Git ignore rules
└── LICENSE             # MIT license

Interactive prompts:

1. Target directory (default: current directory)
2. Plugin name (validates: no "Obsidian", can't end with "Plugin")
3. Plugin ID (validates: no "obsidian", can't end with "plugin", lowercase only)
4. Description (validates: no "Obsidian"/"This plugin", must end with punctuation)
5. Author name
6. GitHub username (optional, auto-generates authorUrl)
7. Minimum Obsidian version

Real-time validation catches common mistakes:

❌ Validation Errors:
   • Plugin ID cannot contain "obsidian"
   • Plugin name cannot end with "Plugin"
   • Description must end with punctuation: . ? ! or )

Usage

Invoking the Skill

Skills are automatically discovered by your agent when present in the project directory. You can also invoke them explicitly using the commands above.

Just ask your agent naturally:

Help me implement a new command for my Obsidian plugin

Your agent will automatically use the Obsidian skill guidelines while helping you write code.

What the Skill Helps With

Code Quality

• Prevents common memory leaks
• Enforces type safety (no unsafe casts)
• Ensures proper resource cleanup
• Follows Obsidian's API patterns

UI/UX Standards

• Enforces sentence case for all UI text
• Prevents redundant naming patterns
• Ensures consistent settings UI

Accessibility (A11y)

• MANDATORY keyboard navigation for all interactive elements
• MANDATORY ARIA labels for icon buttons and controls
• MANDATORY focus indicators with proper CSS styling
• Touch target size requirements (44×44px minimum)
• Screen reader support and announcements
• Tooltip positioning with data-tooltip-position

Security

• Prevents XSS vulnerabilities (no innerHTML/outerHTML)
• Validates manifest structure
• Ensures proper path handling

Platform Compatibility

• iOS compatibility checks (no regex lookbehind)
• Cross-platform path handling
• Mobile-friendly API usage

Submission Ready

• Removes template/sample code
• Validates manifest.json
• Ensures LICENSE compliance
• Follows submission requirements

What's Covered

Most Critical Rules (eslint-plugin-obsidianmd v0.2.3)

The main SKILL.md file highlights the most important rules organized by category:

Submission & Naming:

1. Plugin ID: no "obsidian", can't end with "plugin"
2. Plugin name: no "Obsidian", can't end with "Plugin"
3. Plugin name: can't start with "Obsi" or end with "dian"
4. Description: no "Obsidian", "This plugin", etc.
5. Description must end with .?!) punctuation

Memory & Lifecycle:
6. Use registerEvent() for automatic cleanup
7. Don't store view references in plugin
8. Don't call detachLeavesOfType() in onunload

Type Safety:
9. Use instanceof instead of type casting for TFile/TFolder
10. Use .instanceOf(T) for cross-window DOM checks

UI/UX:
11. Use sentence case for all UI text
12. Sentence case in locale JSON files
13. Sentence case in TS/JS locale modules
14. No "command" in command names/IDs
15. No plugin ID/name in command IDs/names
16. No default hotkeys
17. Use .setHeading() for settings headings

API Best Practices:
18. Use Editor API for active file edits
19. Use Vault.process() for background file mods
20. Use FileManager.trashFile() for file deletion
21. Use Vault.getAbstractFileByPath() instead of iterating files
22. Use normalizePath() for user paths
23. Use Platform API for OS detection
24. Use requestUrl() instead of fetch()
25. No console.log in onload/onunload in production
26. Use built-in AbstractInputSuggest
27. Check minAppVersion for API compatibility

Popout Window Compatibility:
28. Use activeDocument/activeWindow instead of globals
29. Use activeWindow.setTimeout() for timers

Event Handling:
30. Check evt.defaultPrevented in editor-drop/paste handlers

Styling:
31. Use Obsidian CSS variables
32. Scope CSS to plugin containers
33. Don't create <link> or <style> elements

Accessibility (MANDATORY):
34. Make all interactive elements keyboard accessible
35. Provide ARIA labels for icon buttons
36. Define clear focus indicators

Security & Compatibility:

• Don't use innerHTML/outerHTML
• Avoid regex lookbehind

Code Quality:

• Remove all sample/template code
• Don't mutate defaults with Object.assign
• Validate LICENSE copyright holder and year

Detailed Coverage by Topic

Memory Management & Lifecycle

• Using registerEvent(), addCommand(), registerDomEvent(), registerInterval()
• Avoiding view references in plugin
• Not using plugin as component
• Proper leaf cleanup

Type Safety

• Using instanceof instead of type casting
• Avoiding any type
• Using const and let over var

UI/UX Standards

• Sentence case enforcement
• Command naming conventions
• Settings and configuration best practices

File & Vault Operations

• View access patterns
• Editor vs Vault API
• Atomic file operations (Vault.process, processFrontMatter)
• File management and path handling

CSS Styling Best Practices

• Avoiding inline styles
• Using Obsidian CSS variables
• Scoping plugin styles
• Theme support (light/dark)
• Spacing and layout (4px grid)

Accessibility (A11y) - MANDATORY

• Keyboard navigation for all interactive elements
• ARIA labels and roles
• Tooltips with proper positioning
• Focus management
• Focus visible styles (:focus-visible)
• Screen reader support
• Mobile and touch accessibility (44×44px minimum)

Code Quality & Best Practices

• Removing sample code
• Security best practices (XSS prevention)
• Platform compatibility (iOS, mobile)
• API usage patterns
• Async/await patterns
• DOM helpers

Plugin Submission Requirements

• Naming and description validation rules (enforced by Obsidian's release bot)
• Plugin ID, name, and description requirements
• Repository structure and manifest synchronization
• Submission process to obsidianmd/obsidian-releases
• Semantic versioning
• Testing checklist

Examples

Before (Incorrect)

// Multiple issues
class MyPlugin extends Plugin {
  view: CustomView;

  async onload() {
    this.registerView(VIEW_TYPE, (leaf) => {
      this.view = new CustomView(leaf);  // Memory leak!
      return this.view;
    });

    this.addCommand({
      id: 'my-plugin-show-command',  // Redundant naming
      name: 'Show Command',  // Title Case
      hotkeys: [{ modifiers: ['Mod'], key: 's' }],  // Default hotkey
    });

    const file = abstractFile as TFile;  // Unsafe cast
  }

  onunload() {
    this.app.workspace.detachLeavesOfType(VIEW_TYPE);  // Don't do this
  }
}

After (Correct)

// Following all guidelines
class TodoPlugin extends Plugin {
  async onload() {
    this.registerView(VIEW_TYPE, (leaf) => {
      return new CustomView(leaf);  // Create and return directly
    });

    this.addCommand({
      id: 'show',  // Clean naming
      name: 'Show todo',  // Sentence case
      // Let users set their own hotkeys
      checkCallback: (checking: boolean) => {
        const view = this.app.workspace.getActiveViewOfType(MarkdownView);
        if (view) {
          if (!checking) {
            // Perform action
          }
          return true;
        }
        return false;
      }
    });

    if (abstractFile instanceof TFile) {
      // Safe type narrowing
      const file = abstractFile;
    }
  }

  onunload() {
    // Let Obsidian handle cleanup
  }
}

Checklist for Plugin Review

Use this checklist before submitting your plugin:

Submission Validation (will fail bot checks if incorrect):

• Plugin ID: no "obsidian", doesn't end with "plugin", lowercase only
• Plugin name: no "Obsidian", doesn't end with "Plugin"
• Plugin name: doesn't start with "Obsi" or end with "dian"
• Description: no "Obsidian" or "This plugin" phrases
• Description ends with proper punctuation (. ? ! or ))
• Description under 250 characters (recommended)
• manifest.json ID, name, description match submission entry

Code Quality:

• No memory leaks (views/components properly managed)
• Type safety (using instanceof instead of casts)
• All UI text in sentence case
• No redundant words in command names
• Using preferred APIs (Editor API, Vault.process, etc.)
• No iOS-incompatible features (regex lookbehind)
• All sample code removed (MyPlugin, SampleModal, etc.)
• No security issues (innerHTML, XSS vulnerabilities)

Accessibility (MANDATORY):

• All interactive elements keyboard accessible (Tab, Enter, Space)
• ARIA labels on all icon buttons (aria-label)
• Clear focus indicators (:focus-visible with proper CSS)
• Touch targets at least 44×44px (mobile)
• Tooltips positioned with data-tooltip-position

Release Requirements:

• manifest.json valid and version correct
• LICENSE file included
• Mobile tested (if not desktop-only)
• Repository has issues enabled

ESLint Integration

For automatic checking, install the official ESLint plugin and typescript-eslint:

npm install --save-dev eslint typescript-eslint @typescript-eslint/parser eslint-plugin-obsidianmd

Important: The community plugin scanner uses both eslint-plugin-obsidianmd AND typescript-eslint type-checked rules. Most submission failures come from missing the typescript-eslint setup.

See the complete ESLint setup guide for:

• Full eslint.config.mjs that matches the community scanner
• Why recommendedTypeChecked is required (not just recommended)
• Common violations and how to fix them
• Popout window compatibility rules (new in v0.2.3)

Quick config example:

// eslint.config.mjs
import tsParser from "@typescript-eslint/parser";
import tseslint from "typescript-eslint";
import obsidianmd from "eslint-plugin-obsidianmd";

export default [
  { ignores: ["node_modules/**", "main.js"] },
  // Type-checked rules — this is what most people miss
  ...tseslint.configs.recommendedTypeChecked.map(c => ({ ...c, files: ["src/**/*.ts"] })),
  // Obsidian-specific rules
  ...obsidianmd.configs.recommended,
  {
    files: ["src/**/*.ts"],
    languageOptions: {
      parser: tsParser,
      parserOptions: { project: "./tsconfig.json" },
    },
  },
];

Many rules are auto-fixable with:

npx eslint --fix .

Resources

• Obsidian API Docs: https://docs.obsidian.md
• ESLint Plugin: https://github.com/obsidianmd/eslint-plugin
• Sample Plugin: https://github.com/obsidianmd/obsidian-sample-plugin
• Plugin Guidelines: https://docs.obsidian.md/Plugins/Releasing/Plugin+guidelines
• Submission Repo: https://github.com/obsidianmd/obsidian-releases
• Agent Skills Standard: https://agentskills.io

Contributing

Found a missing guideline or rule? Please contribute!

1. Fork this repository
2. Add the guideline to the appropriate file:
   • Main overview: .agents/skills/obsidian/SKILL.md
   • Detailed coverage: .agents/skills/obsidian/reference/*.md
3. Update this README if needed
4. Submit a pull request

Adding New Guidelines

When adding new content:

• Keep SKILL.md under 500 lines (progressive disclosure principle)
• Add detailed content to appropriate reference files
• Use consistent formatting and examples
• Include both incorrect and correct examples

Migration from .claude/skills/

If you previously installed this skill to .claude/skills/obsidian/, you can migrate:

# Move skill files to the new location
mv .claude/skills/obsidian .agents/skills/obsidian

# Keep .claude/commands/ as-is (Claude Code only)

The .claude/skills/ path still works for Claude Code, but .agents/skills/ is the standard location recognized by all providers.

License

MIT License - See LICENSE file for details

Acknowledgments

This skill is based on:

• The official Obsidian Plugin Guidelines
• The eslint-plugin-obsidianmd package (not yet production-ready)
• Community best practices from plugin developers
• Agent Skills standard best practices (progressive disclosure pattern)

Design Philosophy

This skill follows Agent Skills standard best practices:

• Progressive Disclosure: Main SKILL.md (263 lines) provides overview; reference files contain details
• Context Window Efficiency: "The context window is a public good" - optimized token usage
• One-Level-Deep References: All reference files directly under reference/ (no nesting)
• Topic-Based Organization: Each reference file focuses on a specific domain
• Consistent Terminology: Same terms used throughout for clarity

This structure allows your coding agent to load the essential information quickly while having access to comprehensive details when needed.

Note: Guidelines in this skill are based on eslint-plugin-obsidianmd v0.2.3. The plugin is under active development and rules may evolve.