Obsidian Agent Skill

Obsidian Plugin Development Guidelines

Follow these comprehensive guidelines derived from the official Obsidian ESLint plugin rules, submission requirements, and best practices.

Getting Started

Quick Start Tool

For new plugin projects, an interactive boilerplate generator is available:

• Script: tools/create-plugin.js in the skill repository
• Command: Invoke create-plugin using your agent's method (/create-plugin, $create-plugin, or @create-plugin)
• Generates minimal, best-practice boilerplate with no sample code
• Detects existing projects and only adds missing files

Recommend the boilerplate generator when users ask how to create a new plugin, want to start a new project, or need help setting up the basic structure.

Rules Reference (eslint-plugin-obsidianmd v0.4.1)

Submission & Naming

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 1 | Plugin ID | Omit "obsidian"; don't end with "plugin" | Include "obsidian" or end with "plugin" |

| 2 | Plugin name | Omit "Obsidian"; don't end with "Plugin" | Include "Obsidian" or end with "Plugin" |

| 3 | Plugin name | Don't start with "Obsi" or end with "dian" | Start with "Obsi" or end with "dian" |

| 4 | Description | Omit "Obsidian", "This plugin", etc. | Use "Obsidian" or "This plugin" |

| 5 | Description | End with .?!) punctuation | Leave description without terminal punctuation |

Memory & Lifecycle

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 6 | Event cleanup | Use registerEvent() for automatic cleanup | Register events without cleanup |

| 6a | DOM events | Use registerDomEvent() on the plugin or owning component | Pair addEventListener with manual removeEventListener cleanup |

| 7 | View references | Return views/components directly | Store view references in plugin properties or pass plugin as component to MarkdownRenderer |

| 8 | Leaf detachment | Let Obsidian handle leaf cleanup | Call detachLeavesOfType() in onunload |

Type Safety

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 9 | TFile/TFolder | Use instanceof for type checking | Cast to TFile/TFolder; use any; use var |

| 10 | DOM instanceof | Use .instanceOf(T) for DOM Nodes/UIEvents | Use instanceof for cross-window DOM checks |

UI/UX

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 11 | UI text | Sentence case — "Advanced settings" | Title Case — "Advanced Settings" |

| 12 | JSON locale | Sentence case in JSON locale files (recommendedWithLocalesEn) | Title case in locale JSON |

| 13 | TS/JS locale | Sentence case in TS/JS locale modules | Title case in locale modules |

> Note (v0.4.0): ui/sentence-case is now enabled (warn) and enforced on inline UI strings — it was disabled in v0.3.0. Use the recommendedWithLocalesEn config to also check English locale files (rules 12–13).

| 14 | Command names | Omit "command" in command names/IDs | Include "command" in names/IDs |

| 15 | Command IDs | Omit plugin ID/name from command IDs/names | Duplicate plugin ID in command IDs |

| 16 | Hotkeys | No default hotkeys | Set default hotkeys |

| 17 | Settings headings | Use .setHeading() | Create manual HTML headings; use "General", "settings", or plugin name in headings |

Declarative Settings (1.13.0+)

All four settings-tab rules ship as warn in recommended. Rules 17a/17c/17d read minAppVersion from manifest.json; 17b is not version-gated.

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 17a | settings-tab/require-display | Keep display() when minAppVersion < 1.13.0 | Ship declarative-only settings that render nothing on older Obsidian |

| 17b | settings-tab/prefer-setting-definitions | Implement getSettingDefinitions() on every PluginSettingTab | Rely on display() alone — settings won't appear in 1.13+ global search |

| 17c | settings-tab/prefer-update-over-display | Call this.update() to re-render declarative settings | Call this.display() — it's bypassed when definitions are non-empty |

| 17d | settings-tab/no-deprecated-display | Delete display() once minAppVersion >= 1.13.0 and definitions exist | Leave a dead display() behind (auto-fixable) |

| — | Settings data | Keep all persisted data inside plugin.settings | Store sibling keys via saveData() — auto-persist clobbers them |

> Detection caveat: these rules match a bare extends PluginSettingTab only. extends obsidian.PluginSettingTab is out of scope and won't be flagged — but the underlying guidance still applies.

API Best Practices

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 18 | Active file edits | Use Editor API | Use Vault.modify() for active file edits |

| 19 | Background file mods | Use Vault.process() | Use Vault.modify() for background modifications |

| 20 | File deletion | Use FileManager.trashFile() | Use Vault.trash() or Vault.delete() directly |

| 21 | File lookup | Use Vault.getAbstractFileByPath() | Iterate all files with Vault.getFiles().find() |

| 22 | User paths | Use normalizePath() | Hardcode .obsidian path; use raw user paths |

| 23 | OS detection | Use Platform API | Use navigator.platform/userAgent |

| 24 | Network requests | Use requestUrl() | Use fetch() |

| 25 | Logging | Minimize console logging; none in onload/onunload in production | Use console.log in onload/onunload |

| 26 | Input suggest | Use built-in AbstractInputSuggest | Copy Liam's TextInputSuggest implementation |

| 27 | API compatibility | Check minAppVersion for API availability (e.g., getSettingDefinitions() requires 1.13.0) | Use APIs not available in declared minAppVersion |

| 28 | Language detection | Use Obsidian's getLanguage() | Use localStorage.getItem('language') or i18next-browser-languagedetector |

Popout Window Compatibility

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 29 | Document/Window | Use activeDocument and activeWindow | Use global document and window |

| 29a | Getter capture | Capture activeDocument in a variable when the same document is needed later | Call activeDocument at setup and again at cleanup — it follows focus and may return different documents |

| 30 | Timers | Use activeWindow.setTimeout(), setInterval(), etc. | Use bare setTimeout(), setInterval() |

| 31 | Main workspace UI | Use this.app.workspace.containerEl.ownerDocument from settings | Use activeDocument to update main workspace from settings window |

> Note (v0.4.0): prefer-active-doc remains disabled by default — the only Obsidian rule shipped as off. Enable it manually for popout window support.

> Note (v1.13.0): Settings now open in a new window. activeDocument from settings callbacks points to the settings window, not the main vault. Use this.app.workspace.containerEl.ownerDocument to target main workspace UI.

> Note: activeDocument/activeWindow are dynamic getters that track the focused window. A listener added via activeDocument.addEventListener() at setup cannot reliably be removed via activeDocument.removeEventListener() at cleanup. Prefer registerDomEvent() (rule 6a), which captures the target at registration.

Event Handling

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 31 | Editor drop/paste | Check evt.defaultPrevented and call evt.preventDefault() | Handle editor-drop/paste without checking defaultPrevented |

Styling

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 32 | CSS variables | Use Obsidian CSS variables for all styling | Hardcode colors, sizes, or spacing |

| 33 | CSS scope | Scope CSS to plugin containers | Use broad CSS selectors |

| 34 | Style elements | Use styles.css file (no-forbidden-elements) | Create <link> or <style> elements; assign styles via JavaScript |

| 34a | !important | Increase selector specificity or use CSS variables | Use !important — overrides user themes/snippets |

| 34b | :has selector | Toggle classes from TypeScript when conditions change | Use :has — causes broad selector invalidation and performance issues |

Security & Compatibility

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 35 | DOM creation | Use Obsidian DOM helpers (createEl(), createDiv(), createSpan(), createSvg(), createFragment()) via prefer-create-el; linter autofixes activeDocument.createElement() → activeWindow.createEl() (v0.4.1) | Use document.createElement(), document.createDocumentFragment(), etc. |

| 36 | Node.js modules | Guard Node.js imports with Platform.isDesktop check (no-nodejs-modules) | Import Node.js modules without platform guard |

| 37 | iOS compat | Avoid regex lookbehind (iOS < 16.4 incompatibility) | Use regex lookbehind |

Accessibility (MANDATORY)

| # | Rule | ✅ Do | ❌ Don't |

|---|------|--------|----------|

| 38 | Keyboard access | Make all interactive elements keyboard accessible; Tab through all elements | Create inaccessible interactive elements |

| 39 | ARIA labels | Provide ARIA labels for icon buttons; use data-tooltip-position for tooltips | Use icon buttons without ARIA labels |

| 40 | Focus indicators | Use :focus-visible with Obsidian CSS variables; touch targets ≥ 44×44px | Remove focus indicators; make touch targets < 44×44px |

Code Quality

| Rule | ✅ Do | ❌ Don't |

|------|--------|----------|

| Sample code | Remove all sample/template code | Keep class names like MyPlugin, SampleModal |

| Object.assign | Object.assign({}, defaults, overrides) (object-assign) | Object.assign(defaultsVar, other) — mutates defaults |

| LICENSE | Copyright holder must not be "Dynalist Inc."; year must be current (validate-license) | Leave "Dynalist Inc." as holder or use an outdated year |

| Async | Use async/await | Use Promise chains |

| Deprecated packages | Replace flagged npm packages with Node.js built-ins (e.g., builtin-modules → import { builtinModules } from "node:module") | Use packages the scanner flags as replaceable |

Detailed Guidelines

For comprehensive information on specific topics, see the reference files:

Memory Management & Lifecycle

• Using registerEvent(), addCommand(), registerDomEvent(), registerInterval()
• registerDomEvent() vs manual addEventListener (and the activeDocument drift bug)
• 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 (TypeScript, JSON locale, TS/JS locale modules)
• recommendedWithLocalesEn config for locale file checks
• Command naming conventions (no "command", no plugin name, no plugin ID)
• Settings and configuration best practices
• Declarative settings API (1.13+): migration paths, control types, pitfalls

File & Vault Operations

• View access patterns
• Editor vs Vault API
• Atomic file operations
• File management
• Path handling

CSS Styling Best Practices

• Avoiding inline styles
• Using Obsidian CSS variables
• Avoiding !important (use specificity or CSS variables)
• Avoiding :has selector (toggle classes from TypeScript instead)
• Scoping plugin styles
• Theme support
• Spacing and layout

Accessibility (A11y)

• Keyboard navigation (MANDATORY)
• ARIA labels and roles (MANDATORY)
• Tooltips and accessibility
• Focus management (MANDATORY)
• Focus visible styles (MANDATORY)
• Screen reader support (MANDATORY)
• Mobile and touch accessibility (MANDATORY)
• Accessibility checklist

Code Quality & Best Practices

• Removing sample code
• Security best practices
• Platform compatibility
• API usage best practices
• Async/await patterns
• DOM helpers
• Deprecated/replaceable packages (e.g., builtin-modules → node:module)

Plugin Submission Requirements

• Repository structure
• Submission process
• Semantic versioning
• Testing checklist
• Additional resources and important notes

Community Plugin Scanner

• What the scanner runs (ESLint rule sets + checks beyond ESLint)
• Scorecard system (Health, Review, Disclosures, improvement tips)
• Version-stamped — the single file to update as the scanner evolves

ESLint Setup Guide

• Complete ESLint config for community scanner compliance
• Why typescript-eslint recommendedTypeChecked is required
• Common violations and fixes (floating promises, require imports, etc.)
• Popout window compatibility rules

Plugin Submission Validation Workflow

Before submitting a plugin, follow this sequence:

• Run ESLint — npx eslint . using eslint-plugin-obsidianmd; fix all errors AND warnings (warnings affect your Scorecard)
• Validate manifest — Confirm id, name, description, version, and minAppVersion meet naming and formatting rules (rules 1–5)
• Check LICENSE — Copyright holder must not be "Dynalist Inc." and the year must be current
• Test on mobile — Verify no regex lookbehind, no fetch(), and touch targets ≥ 44×44px (skip only if plugin is declared desktop-only)
• Keyboard accessibility audit — Tab through all interactive elements; confirm focus indicators and ARIA labels are present
• Create GitHub Release — Tag must match manifest.json version; attach main.js, manifest.json, and styles.css (optional)
• Submit via community.obsidian.md — Sign in, link GitHub account, navigate to Plugins → New plugin, enter repository URL, review Developer policies, and submit

If ESLint reports new errors after fixing, re-run from step 1.

Scorecard System

Published plugins receive a Scorecard visible on community.obsidian.md. The Scorecard affects user trust and discoverability — a poor score deters users from installing.

Key points:

• Aim for 90%+ overall score
• Fix ALL ESLint warnings, not just errors — warnings are publicly visible
• Use typescript-eslint/recommendedTypeChecked for type-aware checks
• Add GitHub artifact attestation to releases

See Community Plugin Scanner for full details on scanner checks, Health metrics, Review checks, common warnings, and improvement tips.

When Reviewing/Writing Code

Use this checklist for code review and implementation:

• Memory management: Are components and views properly managed?
• Type safety: Using instanceof instead of casts?
• UI text: Is everything in sentence case?
• Command naming: No redundant words?
• File operations: Using preferred APIs?
• Mobile compatibility: No iOS-incompatible features?
• Sample code: Removed all boilerplate?
• Manifest: Correct version, valid structure?
• Accessibility: Keyboard navigation, ARIA labels, focus indicators?

10. Testing: Can you use the plugin without a mouse?

11. Touch targets: Are all interactive elements at least 44×44px?

12. Focus styles: Using :focus-visible and proper CSS variables?

13. Settings: Using declarative getSettingDefinitions() on 1.13+? All saved data co-located in plugin.settings?

Common Patterns

Proper Command Registration

// ✅ CORRECT
this.addCommand({
  id: 'insert-timestamp',
  name: 'Insert timestamp',
  editorCallback: (editor: Editor, view: MarkdownView) => {
    editor.replaceSelection(new Date().toISOString());
  }
});

Safe Type Narrowing

// ✅ CORRECT
const file = this.app.vault.getAbstractFileByPath(path);
if (file instanceof TFile) {
  // TypeScript now knows it's a TFile
  await this.app.vault.read(file);
}

Keyboard Accessible Button

// ✅ CORRECT
const button = containerEl.createEl('button', {
  attr: {
    'aria-label': 'Open settings',
    'data-tooltip-position': 'top'
  }
});
button.setText('⚙️');

button.addEventListener('keydown', (e) => {
  if (e.key === 'Enter' || e.key === ' ') {
    e.preventDefault();
    performAction();
  }
});

Declarative Settings (1.13+)

// ✅ CORRECT — getSettingDefinitions() replaces display() on 1.13+
getSettingDefinitions() {
  return [
    {
      name: 'Mode',
      control: {
        type: 'dropdown',
        key: 'mode',
        defaultValue: 'fast',
        options: { fast: 'Fast', thorough: 'Thorough' },
      },
    },
  ];
}

Themed CSS

/* ✅ CORRECT */
.my-plugin-modal {
  background: var(--modal-background);
  color: var(--text-normal);
  padding: var(--size-4-4);
  border-radius: var(--radius-m);
  font-size: var(--font-ui-medium);
}

.my-plugin-button:focus-visible {
  outline: 2px solid var(--interactive-accent);
  outline-offset: 2px;
}

When helping with Obsidian plugin development, proactively apply these rules and suggest improvements based on these guidelines. Refer to the detailed reference files for comprehensive information on specific topics.