add-community-extension

A workflow for adding a community extension to the Spec Kit catalogue from a GitHub issue. Spec Kit is a toolkit for planning software from written specifications before coding.

In plain words
What is it for?
Use it to process new or updated community-extension submissions and update the community catalog and documentation.
Why use it?
It reduces manual checking by collecting the submission details and validating the repository, files, release, links, license, and dependencies before cataloguing the extension.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/github/spec-kit/add-community-extension
Any agent
npx skills add github/spec-kit --skill add-community-extension
Clone the repo
git clone --depth 1 https://github.com/github/spec-kit

Made for: Claude Code, Codex.

Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,597 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00063 $0.01597
Opus 5 $0.00032 $0.00798
Sonnet 5 $0.00013 $0.00319
Haiku 4.5 $0.00006 $0.00160

Measured yesterday against content hash 3061dc39dfd4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-community-extension 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 yesterday.

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.

.github/skills/add-community-extension/SKILL.md · 175 lines

How it starts

The opening of the file, as written. The whole thing — 175 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add Community Extension

Process an extension submission issue and add or update it in the community catalog.

When to Use

  • A new [Extension] submission issue is filed
  • An existing extension submits an update issue (new version, changed metadata)
  • You need to add or update a community extension in extensions/catalog.community.json and docs/community/extensions.md

Procedure

1. Fetch the submission issue

Read the GitHub issue to extract all metadata:

  • Extension ID, name, version, description, author
  • Repository URL, download URL, homepage, documentation, changelog
  • License, required spec-kit version, optional tool dependencies
  • Number of commands and hooks
  • Tags

2. Validate against publishing rules

Check all of the following (per extensions/EXTENSION-PUBLISHING-GUIDE.md):

Check How
Repository exists and is public Fetch the repository URL
extension.yml manifest present Confirm in repo file listing
README.md present Confirm in repo file listing
LICENSE file present Confirm in repo file listing
GitHub release exists matching version Check releases on the repo page
Download URL is accessible Verify it follows archive/refs/tags/vX.Y.Z.zip pattern and release exists
Extension ID is lowercase-with-hyphens only Regex: ^[a-z][a-z0-9-]*$
Version follows semver Format: X.Y.Z
Submission checklists are all checked Confirm in issue body

3. Determine if this is an add or update

Search extensions/catalog.community.json for the extension ID.

  • Not found → this is a new addition. Proceed to step 4.
  • Found → this is an update. Proceed to step 4 but replace the existing entry in-place instead of inserting.

4. Add or update extensions/catalog.community.json

New extension: Insert the entry in alphabetical order by extension ID.

Update: Replace the existing entry in-place. Update only the fields that changed (typically version, download_url, description, provides, requires, tags, updated_at). Preserve created_at and downloads/stars from the existing entry.

Read the full file on GitHub · 175 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. yesterday First seen · 175 lines · 63 tokens per session scan A 3061dc39dfd4

Subscribe to this mod's changes

add-community-extension is a skill published in the GitHub repository github/spec-kit (132,298 stars, last pushed 3d ago), licensed MIT. It adds 63 tokens to every session and 1,597 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.