SEO Hreflang

Hreflang & International SEO

Overview

This public intake copy packages plugins/antigravity-awesome-skills-claude/skills/seo-hreflang from https://github.com/sickn33/antigravity-awesome-skills into the native Omni Skills editorial shape without hiding its origin.

Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow.

This intake keeps the copied upstream files intact and uses the external_source block in metadata.json plus ORIGIN.md as the provenance anchor for review.

Hreflang & International SEO

Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Validation Checks, Implementation Methods, Hreflang Generation, Hreflang Sitemap Generation, Output, Error Handling.

When to Use This Skill

Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request.

• Use when validating or generating hreflang for multilingual or multiregional sites.
• Use when the user mentions international SEO, language tags, x-default, or hreflang issues.
• Use when auditing locale alternates across HTML, headers, or sitemap implementations.
• Use when the request clearly matches the imported source intent: >.
• Use when the operator should preserve upstream workflow detail instead of rewriting the process from scratch.
• Use when provenance needs to stay visible in the answer, PR, or review packet.

Operating Table

Workflow

This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow.

1. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task.
2. Read the overview and provenance files before loading any copied upstream support files.
3. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request.
4. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes.
5. Validate the result against the upstream expectations and the evidence you can point to in the copied files.
6. Escalate or hand off to a related skill when the work moves out of this imported workflow's center of gravity.
7. Before merge or closure, record what was used, what changed, and what the reviewer still needs to verify.

Imported Workflow Notes

Imported: Validation Checks

1. Self-Referencing Tags

• Every page must include an hreflang tag pointing to itself
• The self-referencing URL must exactly match the page's canonical URL
• Missing self-referencing tags cause Google to ignore the entire hreflang set

2. Return Tags

• If page A links to page B with hreflang, page B must link back to page A
• Every hreflang relationship must be bidirectional (A→B and B→A)
• Missing return tags invalidate the hreflang signal for both pages
• Check all language versions reference each other (full mesh)

3. x-default Tag

• Required: designates the fallback page for unmatched languages/regions
• Typically points to the language selector page or English version
• Only one x-default per set of alternates
• Must also have return tags from all other language versions

4. Language Code Validation

• Must use ISO 639-1 two-letter codes (e.g., en, fr, de, ja)
• Common errors:
  • eng instead of en (ISO 639-2, not valid for hreflang)
  • jp instead of ja (incorrect code for Japanese)
  • zh without region qualifier (ambiguous; use zh-Hans or zh-Hant)

5. Region Code Validation

• Optional region qualifier uses ISO 3166-1 Alpha-2 (e.g., en-US, en-GB, pt-BR)
• Format: language-REGION (lowercase language, uppercase region)
• Common errors:
  • en-uk instead of en-GB (UK is not a valid ISO 3166-1 code)
  • es-LA (Latin America is not a country; use specific countries)
  • Region without language prefix

6. Canonical URL Alignment

• Hreflang tags must only appear on canonical URLs
• If a page has rel=canonical pointing elsewhere, hreflang on that page is ignored
• The canonical URL and hreflang URL must match exactly (including trailing slashes)
• Non-canonical pages should not be in any hreflang set

7. Protocol Consistency

• All URLs in an hreflang set must use the same protocol (HTTPS or HTTP)
• Mixed HTTP/HTTPS in hreflang sets causes validation failures
• After HTTPS migration, update all hreflang tags to HTTPS

8. Cross-Domain Support

• Hreflang works across different domains (e.g., example.com and example.de)
• Cross-domain hreflang requires return tags on both domains
• Verify both domains are verified in Google Search Console
• Sitemap-based implementation recommended for cross-domain setups

Examples

Example 1: Ask for the upstream workflow directly

Use @seo-hreflang to handle <task>. Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer.

Explanation: This is the safest starting point when the operator needs the imported workflow, but not the entire repository.

Example 2: Ask for a provenance-grounded review

Review @seo-hreflang against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why.

Explanation: Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection.

Example 3: Narrow the copied support files before execution

Use @seo-hreflang for <task>. Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding.

Explanation: This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default.

Example 4: Build a reviewer packet

Review @seo-hreflang using the copied upstream files plus provenance, then summarize any gaps before merge.

Explanation: This is useful when the PR is waiting for human review and you want a repeatable audit packet.

Best Practices

Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution.

• Keep the imported skill grounded in the upstream repository; do not invent steps that the source material cannot support.
• Prefer the smallest useful set of support files so the workflow stays auditable and fast to review.
• Keep provenance, source commit, and imported file paths visible in notes and PR descriptions.
• Point directly at the copied upstream files that justify the workflow instead of relying on generic review boilerplate.
• Treat generated examples as scaffolding; adapt them to the concrete task before execution.
• Route to a stronger native skill when architecture, debugging, design, or security concerns become dominant.

Troubleshooting

Problem: The operator skipped the imported context and answered too generically

Symptoms: The result ignores the upstream workflow in plugins/antigravity-awesome-skills-claude/skills/seo-hreflang, fails to mention provenance, or does not use any copied source files at all. Solution: Re-open metadata.json, ORIGIN.md, and the most relevant copied upstream files. Check the external_source block first, then restate the provenance before continuing.

Problem: The imported workflow feels incomplete during review

Symptoms: Reviewers can see the generated SKILL.md, but they cannot quickly tell which references, examples, or scripts matter for the current task. Solution: Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it.

Problem: The task drifted into a different specialization

Symptoms: The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. Solution: Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind.

Imported Troubleshooting Notes

Imported: Common Mistakes

Related Skills

• @00-andruia-consultant - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @00-andruia-consultant-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @10-andruia-skill-smith - Use when the work is better handled by that native specialization after this imported skill establishes context.
• @10-andruia-skill-smith-v2 - Use when the work is better handled by that native specialization after this imported skill establishes context.

Additional Resources

Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding.

Imported Reference Notes

Imported: Implementation Methods

Method 1: HTML Link Tags

Best for: Sites with <50 language/region variants per page.

<link rel="alternate" hreflang="en-US" href="https://example.com/page" />
<link rel="alternate" hreflang="en-GB" href="https://example.co.uk/page" />
<link rel="alternate" hreflang="fr" href="https://example.com/fr/page" />
<link rel="alternate" hreflang="x-default" href="https://example.com/page" />

Place in <head> section. Every page must include all alternates including itself.

Method 2: HTTP Headers

Best for: Non-HTML files (PDFs, documents).

Link: <https://example.com/page>; rel="alternate"; hreflang="en-US",
      <https://example.com/fr/page>; rel="alternate"; hreflang="fr",
      <https://example.com/page>; rel="alternate"; hreflang="x-default"

Set via server configuration or CDN rules.

Method 3: XML Sitemap (Recommended for large sites)

Best for: Sites with many language variants, cross-domain setups, or 50+ pages.

See Hreflang Sitemap Generation section below.

Method Comparison

Imported: Hreflang Generation

Process

1. Detect languages: Scan site for language indicators (URL path, subdomain, TLD, HTML lang attribute)
2. Map page equivalents: Match corresponding pages across languages/regions
3. Validate language codes: Verify all codes against ISO 639-1 and ISO 3166-1
4. Generate tags: Create hreflang tags for each page including self-referencing
5. Verify return tags: Confirm all relationships are bidirectional
6. Add x-default: Set fallback for each page set
7. Output: Generate implementation code (HTML, HTTP headers, or sitemap XML)

Imported: Hreflang Sitemap Generation

Sitemap with Hreflang

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
        xmlns:xhtml="http://www.w3.org/1999/xhtml">
  <url>
    <loc>https://example.com/page</loc>
    <xhtml:link rel="alternate" hreflang="en-US" href="https://example.com/page" />
    <xhtml:link rel="alternate" hreflang="fr" href="https://example.com/fr/page" />
    <xhtml:link rel="alternate" hreflang="de" href="https://example.de/page" />
    <xhtml:link rel="alternate" hreflang="x-default" href="https://example.com/page" />
  </url>
  <url>
    <loc>https://example.com/fr/page</loc>
    <xhtml:link rel="alternate" hreflang="en-US" href="https://example.com/page" />
    <xhtml:link rel="alternate" hreflang="fr" href="https://example.com/fr/page" />
    <xhtml:link rel="alternate" hreflang="de" href="https://example.de/page" />
    <xhtml:link rel="alternate" hreflang="x-default" href="https://example.com/page" />
  </url>
</urlset>

Key rules:

• Include the xmlns:xhtml namespace declaration
• Every <url> entry must include ALL language alternates (including itself)
• Each alternate must appear as a separate <url> entry with its own full set
• Split at 50,000 URLs per sitemap file

Imported: Output

Hreflang Validation Report

Summary

• Total pages scanned: XX
• Language variants detected: XX
• Issues found: XX (Critical: X, High: X, Medium: X, Low: X)

Validation Results

Generated Hreflang Tags

• HTML <link> tags (if HTML method chosen)
• HTTP header values (if header method chosen)
• hreflang-sitemap.xml (if sitemap method chosen)

Recommendations

• Missing implementations to add
• Incorrect codes to fix
• Method migration suggestions (e.g., HTML to sitemap for scale)

Imported: Error Handling

Imported: Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.