our-claude-skills/custom-skills/61-gtm-editor/SKILL.md

name, description

name

description

61-gtm-editor

GTM implementation toolkit. Creates, updates, and modifies GTM tags, triggers, variables via API. Generates Custom HTML with ES5 compliance. Handles workspace lifecycle, DOM analysis for trigger design, and dataLayer code generation. Triggers on "create GTM tag", "generate dataLayer", "modify trigger", "update variable", "inject tracking code", "write custom HTML", "manage GTM", "design tags", "create conversion tag", "set up tracking". NOT for auditing (use gtm-audit) or validation/QA (use gtm-validator).

GTM Editor Skill

Create, modify, and deploy GTM configurations via API. Generates ES5-compliant Custom HTML tags.

Available Tools

GTM Container Management (DTM Agent MCP)

• dtm_status — Check auth and active account/container
• dtm_set_account / dtm_set_container — Switch context
• dtm_list_tags / dtm_get_tag / dtm_create_tag / dtm_update_tag / dtm_delete_tag
• dtm_list_triggers / dtm_get_trigger / dtm_create_trigger / dtm_delete_trigger
• dtm_list_variables / dtm_get_variable / dtm_create_variable / dtm_delete_variable
• dtm_list_folders / dtm_list_workspaces / dtm_get_workspace_status
• dtm_list_versions / dtm_get_live_version / dtm_create_version

Browser Analysis (Chrome DevTools MCP)

• navigate_page — Load page for DOM analysis
• evaluate_script — Inspect forms, buttons, links, CSS selectors
• take_snapshot — Get page structure for trigger design
• list_network_requests — Verify tags fire after changes

Reporting (Notion MCP)

• Write implementation plans and tag configurations to Notion

Tagging Workflow: dataLayer First (MANDATORY)

Always push complexity into the dataLayer, not GTM triggers.

Step 1: Design the dataLayer push FIRST

Before creating any GTM configuration, design the dataLayer.push() that the website should implement. Present this to the user as a code snippet matching their tech stack:

For vanilla JS / static HTML (ES5):

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  'event': 'generate_lead',
  'lead_type': document.getElementById('requestType').value,
  'form_id': 'contact-form'
});

For React / Next.js / TypeScript:

declare global { interface Window { dataLayer: Record<string, any>[]; } }

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  event: 'generate_lead',
  lead_type: selectedType,
  form_id: 'contact-form',
});

For Vue:

window.dataLayer?.push({
  event: 'generate_lead',
  lead_type: this.selectedType,
  form_id: 'contact-form',
});

For PHP / WordPress:

add_action('wp_footer', function() { ?>
<script>
document.getElementById('contact-form').addEventListener('submit', function() {
  window.dataLayer = window.dataLayer || [];
  window.dataLayer.push({
    'event': 'generate_lead',
    'lead_type': document.getElementById('requestType').value
  });
});
</script>
<?php });

ASK the user: "Here's the dataLayer code for your developers. Can they add this to the page? What's your tech stack?"

Step 2: Create simple GTM config

Once dataLayer push is agreed:

• Trigger: Custom Event {{_event}} equals generate_lead (simple, robust)
• Variables: DataLayer Variable for each parameter (e.g., dlv - lead_type)
• Tag: GA4 Event with measurementIdOverride + DLV parameters

Step 3: cHTML fallback (LAST RESORT)

Only if user confirms they CANNOT modify the website code:

1. Create a Custom HTML tag that listens for DOM events
2. The cHTML pushes to dataLayer internally
3. A Custom Event trigger picks it up (same clean pattern)

All cHTML must be ES5-compatible (see ES5 section below).

Decision Tree

Track user action?
  ├─ Can devs add dataLayer.push()? → YES → Simple CE trigger ✅
  ├─ Can't modify code, element has ID? → Use Click ID trigger ✅
  ├─ No ID? → Ask user to add one first
  └─ Nothing possible? → cHTML + CE trigger (last resort)

---

Core Capabilities

1. Tag Creation via GTM API

Create tags directly in GTM — no manual pasting. The API handles workspace lifecycle automatically (auto-creates new workspace if current one is published).

GA4 Event Tags:

GA4 event tags use type "gaawe" with:
  - eventName: the GA4 event name (snake_case)
  - measurementIdOverride: {{GA4 Measurement ID variable}} (NOT measurementId)
  - eventParameters: list of name/value maps

CRITICAL: measurementIdOverride, NOT measurementId GA4 event tags inherit from config — use measurementIdOverride to reference the measurement ID variable. The API rejects measurementId.

2. Trigger Design from DOM Analysis

Analyze page DOM to design precise triggers:

// Extract forms
(function(){var forms=document.querySelectorAll('form');return JSON.stringify(Array.from(forms).map(function(f){return{id:f.id,action:f.action,fields:Array.from(f.querySelectorAll('input,textarea,select')).map(function(el){return{name:el.name,type:el.type,id:el.id}})}}));})()

// Extract CTAs and buttons
(function(){return JSON.stringify(Array.from(document.querySelectorAll('a[class*="btn"],button,[role="button"]')).map(function(el){return{text:(el.textContent||'').trim().substring(0,50),href:el.href||'',classes:el.className,id:el.id}}));})()

Trigger types:

Type	Use For	Key Parameter
linkClick	<a> elements	autoEventFilter with CSS selector
click	Any element	filter on Click ID/Classes
formSubmission	Form submit	filter on Form ID
customEvent	dataLayer events	custom_event_filter on {{_event}}
scrollDepth	Scroll tracking	verticalThresholdsPercent
timer	Time on page	interval, limit
domReady	DOM loaded	No filter needed

3. Custom HTML Generation (ES5 MANDATORY)

GTM Custom HTML uses a JavaScript compiler that does NOT support ES2020+.

FORBIDDEN:

// NO: optional chaining, arrow functions, const/let, template literals,
//     destructuring, spread, async/await

REQUIRED:

// YES: var, function(){}, string concatenation, explicit property access
(function() {
  var form = document.getElementById('contact-form');
  if (!form) return;
  form.addEventListener('submit', function() {
    window.dataLayer = window.dataLayer || [];
    window.dataLayer.push({
      'event': 'generate_lead',
      'lead_type': form.querySelector('#requestType').value
    });
  });
})();

4. Workspace Lifecycle Management

GTM workspaces become read-only after publishing. The DTM Agent auto-handles this:

• If create/update fails with "Workspace is already submitted"
• Auto-creates a new workspace
• Retries the operation
• Caches the workspace ID for subsequent calls

You don't need to manage workspaces manually. Just call dtm_create_tag etc. and it works.

5. DataLayer Code Generation

Generate dataLayer push code for common tracking scenarios:

E-commerce:

// purchase event
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({ ecommerce: null }); // Clear previous
window.dataLayer.push({
  'event': 'purchase',
  'ecommerce': {
    'transaction_id': /* order ID */,
    'currency': 'KRW',
    'value': /* total */,
    'items': [{ item_id: '', item_name: '', price: 0, quantity: 1 }]
  }
});

Forms/Leads:

window.dataLayer.push({
  'event': 'generate_lead',
  'lead_type': /* form type */,
  'form_id': /* form element ID */
});

Korean Market Patterns

Context	Pattern
Currency	KRW (no decimals)
Payment buttons	장바구니, 결제하기, 주문하기, 문의하기
Payment methods	카카오페이, 네이버페이, 토스, 신용카드
Platforms	Kakao Pixel (track.kakao.com), Naver Analytics (wcs.naver.net)

Supported Tag Types

GTM Type	Name	Platform
googtag	Google Tag	GA4 config
gaawe	GA4 Event	GA4 events
gclidw	Conversion Linker	Google Ads
awct	Ads Conversion	Google Ads
html	Custom HTML	Any (Meta, PostHog, Kakao, etc.)
cvt_MQDKZ	Clarity	Microsoft Clarity
cvt_WF3R3	Amplitude	Amplitude

FB Conversions API Integration

When creating tags that should trigger FB CAPI:

1. Check existing FBEventName mapping table (Regex Table variable)
2. If your custom event isn't mapped, add a new rule: event_name → FB_Standard_Event
3. Key mappings: generate_lead → Lead, purchase → Purchase, page_view → PageView

Workflow

1. Analyze: Use Chrome DevTools to inspect the page (or receive from gtm-audit Mode D)
2. Design: Determine events, triggers, variables needed
3. Create: Use DTM Agent MCP tools to create in GTM
4. Verify: Hand off to gtm-validator for QA
5. Document: Write implementation details to Notion

Trigger Design: IDs First (MANDATORY)

Always prefer element id over CSS selectors. IDs survive redesigns; CSS selectors break.

Before creating ANY click/form trigger:

1. Check if the target element has an id attribute via Chrome DevTools evaluate_script
2. If it has an ID → use Click ID or Form ID filter
3. If it does NOT have an ID → ASK the user before falling back to CSS:

   "This element doesn't have an ID. Can you add one to the website/app code? Suggested: id="[section]-[element]-[action]" e.g., id="hero-btn-consult""

4. Only use CSS selectors when the user explicitly confirms they cannot modify the HTML

Priority order:

1. Element ID (Click ID equals "hero-btn-consult")
2. Data attribute (Click Element matches CSS [data-track="consult"])
3. Form ID (Form ID equals "contact-form")
4. CSS selector (last resort — document which selectors are used)

Suggested ID naming: [section]-[element]-[action]

• Navigation: nav-about, nav-services, nav-insights
• CTAs: hero-btn-consult, cta-btn-booking
• Forms: contact-form, newsletter-form
• Footer: footer-social-linkedin, footer-email

Rules

• Always use dtm_status first to verify auth and active container
• Always use measurementIdOverride for GA4 event tags (NOT measurementId)
• Always prefer element IDs for triggers — ask user to add IDs before using CSS selectors
• All Custom HTML must be ES5-compatible
• Use --dry-run conceptually — verify trigger selectors via Chrome DevTools before creating
• Rate limit: space API calls 1 second apart in batch operations
• Never delete tags without explicit user confirmation — move to Archive folder instead
• After creating tags, suggest user run gtm-validator to verify