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 melodic-software/claude-code-plugins --skill prerequisitesgit clone --depth 1 https://github.com/melodic-software/claude-code-pluginsWrote 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/melodic-software/claude-code-plugins/prerequisites)<a href="https://agentmods.dev/skills/melodic-software/claude-code-plugins/prerequisites"><img src="https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/prerequisites/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/melodic-software/claude-code-plugins/prerequisites"><img src="https://agentmods.dev/badge/skills/melodic-software/claude-code-plugins/prerequisites.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00047 | $0.01171 |
| Opus 5.5 | $0.00019 | $0.00468 |
| Sonnet 5.5 | $0.00009 | $0.00234 |
| Haiku 4.5 | $0.00005 | $0.00117 |
Grade A, and why
prerequisites scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Purpose
Answer "does this host have what the enabled plugins need?" Read prerequisites.json in each enabled plugin, resolve each declared dependency with the shared Node checker, and print one table. Do not install, download, or run npx.
Claim: the fleet check lives here, not as a deps action on plugins and not as a machine-health category. plugins brings marketplace versions current and is disable-model-invocation: true. This question is read-only and model-invocable. Each plugin that needs an external dependency declares it in prerequisites.json at the plugin root, in the schema docs/conventions/prerequisites/ owns, which this skill and the per-plugin check both read.
- Pointer: when checking what
disable-model-invocationgoverns, fetch skills: frontmatter reference live. As of: 2026-10-11. Recheck trigger: a Claude Code release adds a manifest field for external binaries, orpluginsbecomes model-invocable for a read-only action.
Run
node "${CLAUDE_SKILL_DIR}/scripts/check-prerequisites.mjs"
The table columns are plugin, id, kind, need, status, the check skill, and the install hints. missing=N present=M is the last line. The status is present, missing, outdated (below its version floor), unverified (the version could not be read) or agent-check (an MCP server only the agent can see). Exit 1 means a required entry is missing or below its floor, and a missing optional entry leaves exit 0. Exit 2 means no plugin roots could be read, the listing was not JSON, or a prerequisites.json fails the schema.
With no arguments and a claude executable on PATH, the script reads the enabled set and each installPath from claude plugin list --json. That output lists installs across every project, so it keeps user and managed rows, and project or local rows only when their projectPath is the current project (CLAUDE_PROJECT_DIR, else the git toplevel); an id resolves by its most specific scope, so user-enabled and project-disabled is disabled. When claude is absent or prints nothing, it merges enabledPlugins from the settings files instead: the user settings in ~/.claude (CLAUDE_CONFIG_DIR overrides that directory) and the project's .claude/settings.json and settings.local.json. A file holding any non-Boolean enabledPlugins value contributes none of its keys, and the managed scope is not read there. Output that is not a JSON list stops the run with exit 2 instead. Only when none of that state exists does it scan plugins/*/prerequisites.json in the current repository; a state with nothing enabled prints an empty table.
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 3d ago Changed · +4 lines 088d9f846df3
- 12d ago Changed · +2 lines 614990af95b2
- 13d ago Changed fcaa3eeb38f3
- 14d ago Changed · +1 lines 7c5844720cf7
- 15d ago Changed 654d9bbe2746
- 16d ago First seen · 39 lines · 47 tokens per session scan A f0c420ff1dd3
prerequisites is a skill published in the GitHub repository melodic-software/claude-code-plugins (25 stars, last pushed today), licensed MIT. It adds 47 tokens to every session and 1,171 once invoked, about $0.0002 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 2026-09-30.
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