Agent Skills
› sediman-agent/OpenSkynet
› canonical-tag
canonical-tag
GitHub指导配置规范标签以解决重复内容、URL信号合并及首选URL声明。涵盖HTTPS重定向、www与非www统一、多语言处理及Next.js等框架实现，避免链式引用。
Trigger Scenarios
用户提到canonical或canonical URL
需要修复重复内容问题
希望统一URL信号或合并URL
涉及HTTP到HTTPS的迁移
Install
npx skills add sediman-agent/OpenSkynet --skill canonical-tag -g -y
SKILL.md
Frontmatter
{
"name": "canonical-tag",
"metadata": {
"version": "1.0.1"
},
"description": "When the user wants to configure canonical URLs, fix duplicate content, or consolidate URL signals. Also use when the user mentions \"canonical,\" \"canonical URL,\" \"duplicate content,\" \"duplicate content fix,\" \"preferred URL,\" or \"URL consolidation.\" For GSC duplicates, use google-search-console."
}
SEO Technical: Canonical
Guides canonical tag configuration to consolidate duplicate content and declare preferred URLs.
When invoking: On first use, if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output.
Scope (Technical SEO)
- Duplicate site versions: HTTPS vs HTTP; www vs non-www; trailing slash (/page vs /page/) — choose one, 301 redirect others
- Duplicate content: Canonical tags; consolidate and 301 to preferred URL
- HTTPS: SSL/TLS; secure connection; ranking signal since 2014
Initial Assessment
Check for project context first: If .claude/project-context.md or .cursor/project-context.md exists, read it for site URL and language structure.
Identify:
- Site URL: Base domain
- Duplicate scenarios: Multi-language, query params, pagination, alternate URLs
- Framework: Next.js, React, static, etc.
Canonicalization Methods (Choose by Scenario)
| Method | When | Strength |
|---|---|---|
| 301 redirect | Preferred; server can redirect | Strongest — permanent redirect |
| Canonical tag | Cannot redirect (e.g. params, pagination) | Strong — HTML signal |
| robots.txt | Block non-canonical paths | Weak — advisory only |
Use 301 for HTTP→HTTPS, www variants, trailing slash. Use canonical for params, pagination, UTM.
HTTPS & Security
HTTPS is a ranking signal (Google, 2014). Users and crawlers should access only the HTTPS version.
| Requirement | Action |
|---|---|
| SSL/TLS certificate | Install valid certificate; use Let's Encrypt for free |
| 301 redirect | HTTP → HTTPS; all HTTP requests redirect to HTTPS |
| Mixed content | No HTTP resources on HTTPS pages; fix mixed content warnings |
| HSTS | Optional; Strict-Transport-Security header for repeat visitors |
WWW vs non-WWW: Choose one preferred version; 301 redirect the other. See canonical rules above.
When to Use Canonical
- Multi-language: Each language version has its own canonical; use hreflang with canonical
- Same content, multiple URLs: Params, pagination, tracking params, www vs non-www, trailing slash (/page vs /page/)
- Self-referencing: Canonical should point to self or the preferred version
- Avoid chain canonical: A→B→C is invalid
Rules
| Rule | Note |
|---|---|
| Absolute URL | Include https:// |
| Consistency | Must match current page URL or the chosen preferred version |
| No chains | A→B→C is invalid |
Implementation Patterns
Next.js (metadata)
export const metadata = {
alternates: {
canonical: "https://example.com/page-slug",
languages: {
zh: "https://example.com/zh/page-slug",
en: "https://example.com/page-slug",
"x-default": "https://example.com/page-slug",
},
},
};
HTML (generic)
<link rel="canonical" href="https://example.com/page-slug" />
Server Redirects (301)
Apache (.htaccess):
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
Nginx:
return 301 https://$host$request_uri;
Relationship to Other Technical SEO
- Sitemap: URLs in sitemap should match canonical
- IndexNow: Submit canonical URLs
Output Format
- Canonical URL for each page type
- Implementation (metadata or HTML)
- Multi-language setup if applicable
- References: Alignify URL optimization; Google Canonical
Related Skills
- url-structure: URL hierarchy and format; canonical handles duplicate variants (HTTPS, www, trailing slash)
- localization-strategy: hreflang + canonical for multi-language
- xml-sitemap: Sitemap URLs should match canonical
- indexnow: Submit canonical URLs
- google-search-console: Find duplicate content in Coverage report
- indexing: Resolve indexing issues
- site-crawlability: Crawl budget; redirect chains; canonical reduces duplicate crawl waste
Version History
- c9d8953 Current 2026-07-05 19:57
