Upstream Sources Registry

Q: What is a Claude Code skill and how does the Upstream Sources Registry skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Upstream Sources Registry is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Content · Sub-category: content-misc · Last updated: 2026-09-28

ai:claude

Owns the configurable registry of official Codex upstream sources — docs.Codex.com spec/guide pages, changelog/release notes, and informal signals from the anthropics/Codex GitHub repo (issues, discussions, example plugins) — that plugin-devkit's rules and conventions trace back to. Classifies each source by authority tier and volatility, derives a re-check priority from those plus how many local rules cite it, tracks last-verified state, and performs the actual freshness check (WebFetch/WebSearch) on request. Supports enabling/disabling sources, overriding a source's rank, and adding custom sources (blog posts, papers, other repos). Use when a dev-rules command needs to know which sources to check and how stale the last check is, or when a maintainer asks "is there an official source backing this rule", "what sources cover X", "add a source to the registry", or "check registry freshness".

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

A persisted, configurable record of the official Codex sources that plugin-devkit's rules and conventions are supposed to trace back to — so "verify against official docs" means checking a known, classified, freshness-tracked list instead of re-discovering the source landscape from scratch on every single command run.

What this skill does

Upstream Sources Registry is a community-contributed Claude Code skill in the content-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/upstream-sources-registry/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when a dev-rules command needs to know which sources to check and how stale the last check is, or when a maintainer asks "is there an official source backing this rule", "what sources cover X", "add a source to the registry", or "check registry freshness".

Who uses this skill

The Upstream Sources Registry Claude Code skill is built for content creators, marketers, copywriters, SEO professionals, and editorial teams. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 196,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/upstream-sources-registry
curl -L https://claudskills.com/skills/upstream-sources-registry/SKILL.md \
  -o ~/.claude/skills/upstream-sources-registry/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/upstream-sources-registry/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/upstream-sources-registry/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\upstream-sources-registry\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Upstream Sources Registry Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/upstream-sources-registry/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Upstream Sources Registry skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Upstream Sources Registry skill?

Use Upstream Sources Registry when your Claude Code task falls under the Content category — specifically in the content misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Upstream Sources Registry" or describe the task and let Claude pick). Browse related skills at /category/content/.

What is a Claude Code skill and how does the Upstream Sources Registry skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Upstream Sources Registry is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Content category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/AndreHahm/andres-cc-marketplace/blob/6eeae17f9261609dcd2aee09955b0eca5ceec709/.agents/skills/upstream-sources-registry/SKILL.md
License: Apache-2.0
Author: AndreHahm

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

AndreHahm. (2026). Upstream Sources Registry [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/upstream-sources-registry/

BibTeX

@misc{upstream-sources-registry-2026,
  author    = {AndreHahm},
  title     = {Upstream Sources Registry [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/upstream-sources-registry/}
}

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Badge

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Security scan

Grade A · scanned 2026-09-28 — free static scan against the OWASP Agentic Skills Top 10.

The scan flagged 1 of 10 categories (prompt-injection), including a high-severity pattern. Patterns shown inside code fences are weighted as examples rather than instructions — read the grading methodology for what this does and does not guarantee.

⚠ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/upstream-sources-registry/#security)