canonical-header SKILL.md skillA
canonical-header from thedaviddias/front-end-checklist is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add thedaviddias/front-end-checklist/canonical-header@git:20261004.4b0ddb9Pins git:20261004.4b0ddb9 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- thedaviddias/front-end-checklist
- Path
skills/canonical-header/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261004.4b0ddb9, committed Oct 4, 2026
- First version recorded
- May 29, 2026
- Size
- 1,726 bytes
- Repository stars
- 74,516
- License
- MIT
Use when auditing metadata, crawlability, structured data, or indexability related to Sync HTML canonical tags and Link headers. Verify the rendered HTML and HTTP response rather than relying only on source files.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Sync HTML canonical tags and Link headers Conflicting canonical-url signals can lead search engines to ignore both declarations, potentially causing duplicate content issues and incorrect indexing. ## Quick Reference - Ensure the `rel="canonical"` tag in your HTML matches the `Link` canonical-url header if both are used - Avoid sending conflicting signals to search engines about the primary version of a page - Maintain consistency across all methods of declaring your canonical URL ## Check Compare the HTML canonical tag with the HTTP Link header to ensure they point to the exact same URL. ## Fix Update either the HTML tag or the HTTP header so that they provide a consistent canonical URL signal. ## Explain Explain the risks of sending conflicting technical SEO signals to search engine crawlers. ## Code Review Review metadata generation, rendered HTML, structured data, and response headers related to Sync HTML canonical tags and Link headers. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output. --- For full implementation details, code examples, and framework-specific guidance, …
Read the whole file at its exact version.
How to install
mdr add thedaviddias/front-end-checklist/canonical-header@sha256:1d247e6d29ad7470The line at the top of this page pins the label git:20261004.4b0ddb9, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_mwjbbnqn4zm5j5rg)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between May 29, 2026 and Oct 4, 2026, about one every 128 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261004.4b0ddb9 latest | 2026-10-04 | 4b0ddb9 | 1,726 B | A | view · diff |
| git:20260529.7c05904 | 2026-05-29 | 7c05904 | 1,732 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (1726 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
thedaviddias/front-end-checklist · 74,516 stars · license MIT · pushed 2026-10-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_mwjbbnqn4zm5j5rg GET https://markdownregistry.com/api/v1/resolve?ref=thedaviddias/front-end-checklist/canonical-header GET https://markdownregistry.com/api/v1/blob/1d247e6d29ad7470e72084ba3c01ec85cfdd44453c48f76e7da8823dfad5048e
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.