Borrowing it
Nothing to install: this file belongs to yahor-punko/mavericks-os. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/yahor-punko/mavericks-os/main/.claude/skills/session-start/SKILL.mdgit clone --depth 1 https://github.com/yahor-punko/mavericks-osWrote 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/yahor-punko/mavericks-os/session-start)<a href="https://agentmods.dev/skills/yahor-punko/mavericks-os/session-start"><img src="https://agentmods.dev/badge/skills/yahor-punko/mavericks-os/session-start/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/yahor-punko/mavericks-os/session-start"><img src="https://agentmods.dev/badge/skills/yahor-punko/mavericks-os/session-start.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 | $0.00088 | $0.03294 |
| Opus 5.5 | $0.00035 | $0.01318 |
| Sonnet 5.5 | $0.00018 | $0.00659 |
| Haiku 4.5 | $0.00009 | $0.00329 |
Grade B, and why
session-start scanned grade B with 1 finding 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 2d 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.
Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
- `permission_mode_conflict` — present only when a readable user-global `~/.claude/settings.json` `defaultMode` differs from the project-file resolution; shape `{project, user_global}`, a fact report only — never render The source is not reproduced here
A licence we could not identify
The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.
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.
- 2d ago Changed · +39 lines 0469859910b7
- 3d ago Changed · +11 lines b919c190cb34
- 4d ago Changed · +11 lines a848859b9d6b
- 1mo ago Changed b52c99f57a53
- 1mo ago Changed · +6 lines 04230e0e465e
- 1mo ago Changed · +14 lines 802ce4cb1f30
- 1mo ago First seen · 147 lines · 88 tokens per session scan B 9e1f17eccb0a
session-start is a skill published in the GitHub repository yahor-punko/mavericks-os (103 stars, last pushed 3d ago), with no licence file. It adds 88 tokens to every session and 3,294 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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