seo-hreflang

seo-hreflang is a skill for Claude Code from citedy/adclaw. It costs 71 tokens per session (2,233 once invoked), scanned A, a copy of seo-hreflang, Apache-2.0.

A checker and generator for hreflang tags, which tell search engines which language or regional version of a page to show. It supports tags in HTML, HTTP headers, and XML sitemaps.

In plain words
What is it for?
Auditing or creating language and country targeting for websites with multiple translations or regional versions.
Why use it?
It detects missing self-links, missing return links, invalid language codes, and incorrect fallback settings that can make international targeting unreliable.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter.

Good fit Auditing or creating language and country targeting for websites with multiple translations or regional versions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/citedy/adclaw/seo-hreflang
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add citedy/adclaw --skill seo-hreflang
Clone the repo
git clone --depth 1 https://github.com/citedy/adclaw

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for seo-hreflang

README.md
[![agentmods](https://agentmods.dev/badge/skills/citedy/adclaw/seo-hreflang/github.svg)](https://agentmods.dev/skills/citedy/adclaw/seo-hreflang)
Your own site
<a href="https://agentmods.dev/skills/citedy/adclaw/seo-hreflang"><img src="https://agentmods.dev/badge/skills/citedy/adclaw/seo-hreflang/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for seo-hreflang

Your own site · 80×15
<a href="https://agentmods.dev/skills/citedy/adclaw/seo-hreflang"><img src="https://agentmods.dev/badge/skills/citedy/adclaw/seo-hreflang.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,233 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 88% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00071 $0.02233
Opus 5 $0.00036 $0.01117
Sonnet 5 $0.00014 $0.00447
Haiku 4.5 $0.00007 $0.00223

Measured 8d ago against content hash 49f3f15484fb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

seo-hreflang scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

88% identical to seo-hreflang — 100 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

src/adclaw/agents/skills/seo-hreflang/SKILL.md · 200 lines

How it starts

The opening of the file, as written. The whole thing — 200 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hreflang & International SEO

Validate existing hreflang implementations or generate correct hreflang tags for multi-language and multi-region sites. Supports HTML, HTTP header, and XML sitemap implementations.

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

Read the full file on GitHub · 200 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 200 lines · 71 tokens per session scan A 49f3f15484fb

Subscribe to this mod's changes

seo-hreflang is a skill published in the GitHub repository citedy/adclaw (37 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 71 tokens to every session and 2,233 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to seo-hreflang, differing in 100 lines, and is treated as a copy.