install

A command that downloads a capsule, which is a reusable Claude Code skill stored in a GitHub Gist, into the current project's skills folder. Claude Code then loads that skill automatically in later sessions for the project.

In plain words
What is it for?
Use it when you have a GitHub Gist ID for a capsule you want to install. The capsule is saved under the project's .claude/skills/ directory.
Why use it?
It avoids manually copying and placing shared skill files into a project. It also reports whether the installation succeeded or failed.

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/fragcap/plugin/install
Any agent
npx skills add fragcap/plugin --skill install
Clone the repo
git clone --depth 1 https://github.com/fragcap/plugin

Made for: Claude Code, Codex.

Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 398 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 $0.00035 $0.00398
Opus 5 $0.00017 $0.00199
Sonnet 5 $0.00007 $0.00080
Haiku 4.5 $0.00003 $0.00040

Measured yesterday against content hash 5ddf3a35679c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

install 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.

skills/install/SKILL.md · 40 lines

What it actually says

Install Capsule

Fetch a published capsule (SKILL.md) from GitHub Gist and install it into the current project so Claude Code loads it automatically in future sessions.

Script Convention

FRAGCAP_DATA="${CLAUDE_PLUGIN_DATA}" node "${CLAUDE_PLUGIN_ROOT}/scripts/<n>.mjs" [args]

If a script exits with a non-zero code or returns { error: "..." }, stop immediately and surface the error to the user. Never silently retry with a different command or skip the step.

When to Activate

  • User runs /fragcap:install <gist-id>
  • User explicitly asks to install a capsule (e.g., "install this", "save this to my project")

Flow

  1. Get gist ID:

    • If $ARGUMENTS is provided, use it as the gist ID.
    • Otherwise, ask: "Which capsule would you like to install? Provide a gist ID or run /fragcap:search to find one."
  2. Install — run install-capsule.mjs <gist-id>.

  3. Result:

    • Success: show the installed path, capsule description, and tags. Explain that Claude Code will automatically load this skill in future sessions within this project.
    • Error: show the error message.

Notes

  • Capsules are installed to .claude/skills/ in the current working directory.
  • Claude Code automatically loads all .md files in .claude/skills/ as context.
  • Installing the same capsule again will overwrite the previous version.
  • To uninstall, simply delete the .md file from .claude/skills/.
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 · 40 lines · 35 tokens per session scan A 5ddf3a35679c

Subscribe to this mod's changes

install is a skill published in the GitHub repository fragcap/plugin (2 stars, last pushed 5mo ago), licensed MIT. It adds 35 tokens to every session and 398 once invoked, about $0.0002 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 2026-08-31.

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