A full validation command for the Sailfin compiler. It clears the build directory and runs the project's verification process, including checking that the compiler can build itself.

Use it before calling a feature complete, before making a release, or after changes that might affect self-hosting.

It provides a clean check after structural changes instead of relying on an incomplete or stale build.

How SailfinIO/sailfin configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to SailfinIO/sailfin. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/SailfinIO/sailfin/main/.claude/skills/check/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/SailfinIO/sailfin

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/sailfinio/sailfin/check/github.svg)](https://agentmods.dev/skills/sailfinio/sailfin/check)

Your own site

<a href="https://agentmods.dev/skills/sailfinio/sailfin/check"><img src="https://agentmods.dev/badge/skills/sailfinio/sailfin/check/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/sailfinio/sailfin/check"><img src="https://agentmods.dev/badge/skills/sailfinio/sailfin/check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 452 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00053	$0.00452
Opus 5.5	$0.00021	$0.00181
Sonnet 5.5	$0.00011	$0.00090
Haiku 4.5	$0.00005	$0.00045

Measured 1mo ago against content hash 910b8b7b7199, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

check 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/run-check.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

.claude/skills/check/SKILL.md · 47 lines

The source is not reproduced here

Licensed GPL-2.0

The repository is licensed GPL-2.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Files

What ships with it

1 file 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.

scripts/run-check.sh 1.3 KB runs code

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.

1mo ago First seen · 47 lines · 53 tokens per session scan A 910b8b7b7199

Subscribe to this mod's changes

check is a skill published in the GitHub repository SailfinIO/sailfin (8 stars, last pushed 2d ago), licensed GPL-2.0. It adds 53 tokens to every session and 452 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 2026-10-02.

Git and workflow Releases Testing capability-based-security compile-time-safety compiler concurrency programming-language runtime

check next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
checkSailfinIO/sailfin	Skill	8	2d ago	GPL-2.0	A	53	Claude Code
prepare-releasepingdotgg/t3code	Skill	48k	today	MIT	A	153	Claude Code, Codex
codew-release-qa-sweepHmbown/CodeWhale	Skill	41k	5d ago	MIT	A	31	Claude Code, Codex
validate-release-greendiegosouzapw/OmniRoute	Skill	83k	5d ago	MIT	A	47	Claude Code, Codex
verify-and-shipcyrusagents/cyrus	Skill	883	yesterday	Apache-2.0	A	32	Claude Code, Codex
shipplugin87/ux-ui-agent-skills	Skill	3.1k	10d ago	MIT	A	34	Claude Code
ship-workflowMathews-Tom/armory	Skill	340	5d ago	MIT	A	158	Claude Code

sailfin: Skill for Claude Code