github/spec-kit-copilot is a repository of GitHub Copilot integrations for Spec Kit, a toolkit for developing software through a structured specification-first workflow. It provides Copilot-specific commands, skills, canvases, and related workflow components for users of the Copilot CLI, Copilot App, and VS Code.
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.
npx skills add github/spec-kit-copilot --skill speckit-extensiongit clone --depth 1 https://github.com/github/spec-kit-copilotWrote 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.
[](https://agentmods.dev/skills/github/spec-kit-copilot/speckit-extension)<a href="https://agentmods.dev/skills/github/spec-kit-copilot/speckit-extension"><img src="https://agentmods.dev/badge/skills/github/spec-kit-copilot/speckit-extension/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.
<a href="https://agentmods.dev/skills/github/spec-kit-copilot/speckit-extension"><img src="https://agentmods.dev/badge/skills/github/spec-kit-copilot/speckit-extension.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00100 | $0.00777 |
| Opus 5.5 | $0.00040 | $0.00311 |
| Sonnet 5.5 | $0.00020 | $0.00155 |
| Haiku 4.5 | $0.00010 | $0.00078 |
Grade A, and why
speckit-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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Spec Kit — extensions
Manage spec-kit extensions with the Specify CLI specify extension command
group. Extensions add reusable commands/hooks to a spec-kit project.
Prerequisite: needs the
specifyCLI. Ifspecify --versionfails, install it with the speckit-cli-setup skill first.
When to use
- Find, install, update, or remove a spec-kit extension.
- Temporarily enable/disable an extension or adjust its resolution priority.
- Add or manage extension catalog sources.
How to invoke
# Discover
specify extension list
specify extension list --json # machine-readable installed inventory (CLI >= 1.0.7)
specify extension search <query>
specify extension info <name>
# Install
specify extension add <name>
specify extension add <name> --force # overwrite if already installed
specify extension add <path> --dev # install from a local directory
specify extension add <name> --from <url> # install from a custom URL
specify extension add <name> --priority <n> # lower number = higher precedence
# Lifecycle
specify extension update [<name>] # update one or all extensions
specify extension enable <name>
specify extension disable <name>
specify extension set-priority <name> <n>
specify extension remove <name>
# Catalogs (sources extensions are resolved from)
specify extension catalog list
specify extension catalog add <https-url> --name <name> [--install-allowed] [--priority <n>] [--description <text>]
specify extension catalog remove <name>
Extension catalog URLs must use HTTPS. New catalogs are not install-allowed by default — pass
--install-allowedto permit installing extensions from them.
Notes
- Resolution priority: lower number = higher precedence (default
10). specify extension list --jsonrequires Specify CLI >= 1.0.7 and returns installed extensions only, even when combined with--availableor--all. Each item includesid,name,description,version, nullableauthor,priority,enabled, normalizedsource, andprovidescounts for commands, templates, scripts, and hooks.- Prefer
specify extension searchfirst so you install the correct extension ID. --devis for local development of an extension; point it at the extension's source directory.- When the project was initialized in skills mode (see the speckit-init skill),
an installed extension's commands land as
.github/skills/speckit-<cmd>/SKILL.md. To make Copilot pick up the new skills in the current session, run/skills reload(no restart needed). They are also loaded automatically on the next session start.
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.
- 1mo ago Changed · +6 lines · +17 tokens per session 528c9e9d8193
- 1mo ago First seen · 63 lines · 83 tokens per session scan A aba1330e6128
speckit-extension is a skill published in the GitHub repository github/spec-kit-copilot (18 stars, last pushed today), licensed MIT. It adds 100 tokens to every session and 777 once invoked, about $0.0004 per session on Opus 5.5. 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.
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