preflight

preflight is a skill for Claude Code, Codex from hxy91819/mason-skills. It costs 36 tokens per session (1,115 once invoked), scanned A, original, MIT.

A pre-work check for the credentials, permissions, command-line tools, packages, and external systems a task needs. It tests available parts of the execution path and records what is verified, fixed, or still requires approval.

In plain words
What is it for?
Use it after a specification is ready and before implementation. It helps prepare tasks involving APIs, cloud systems, internal services, command-line tools, or other external dependencies.
Why use it?
It finds missing access or dependencies before implementation begins instead of leaving an unattended coding agent blocked halfway through. It also distinguishes tested access from assumptions.

Skill for Claude CodeCodex

Written for Claude Code and Codex: disable-model-invocation in frontmatter, but also agents/openai.yaml present.

Good fit Use it after a specification is ready and before implementation. It helps prepare tasks involving APIs, cloud systems, internal services, command-line tools, or other external dependencies.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hxy91819/mason-skills/preflight
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.

Any agent
npx skills add hxy91819/mason-skills --skill preflight
Clone the repo
git clone --depth 1 https://github.com/hxy91819/mason-skills

Made for: Claude Code, Codex.

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.

agentmods badge for preflight

README.md
[![agentmods](https://agentmods.dev/badge/skills/hxy91819/mason-skills/preflight/github.svg)](https://agentmods.dev/skills/hxy91819/mason-skills/preflight)
Your own site
<a href="https://agentmods.dev/skills/hxy91819/mason-skills/preflight"><img src="https://agentmods.dev/badge/skills/hxy91819/mason-skills/preflight/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.

agentmods 80×15 button for preflight

Your own site · 80×15
<a href="https://agentmods.dev/skills/hxy91819/mason-skills/preflight"><img src="https://agentmods.dev/badge/skills/hxy91819/mason-skills/preflight.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,115 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 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 5.1 $0.00036 $0.01115
Opus 5 $0.00018 $0.00558
Sonnet 5 $0.00007 $0.00223
Haiku 4.5 $0.00004 $0.00112

Measured today against content hash 23cc329d000b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

preflight 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 today.

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.

common-skills/preflight/SKILL.md · 27 lines

What it actually says

开工前核查:spec 或当前指令所依赖的凭据、权限、工具和外部环境是否真正可用。目标:让后续执行任务的 worker 能长时间无人值守运行——worker 往往用较弱的模型,遇到障碍和歧义无法自行解决,所以凡是会让它跑到一半停下来等用户确认的障碍(缺权限、缺工具、缺 token)都在开工前移除或预先授权,而不是开工后撞上。在 to-spec 之后、implement 之前跑最合适。上下文已有 spec 就核查 spec,否则以当前指令为目标;两者都构不成完整目标时,先请用户补充,不做臆测。

流程

  1. 列依赖清单。 扫描 spec/指令中每个将被使用的外部系统、CLI、环境和安装包,逐项写明用途(如“触发 zhiyan 测试流水线”)。spec 没提但完成目标明显必需的外部环节(spec 只说“发布”却没说发布到哪)不算臆造:列为缺口,向用户确认后补进清单或修订 spec——漏掉它,worker 会在执行中段撞上。典型类别:凭据与权限(token、账号、云 API profile,内部系统如 zhiyan/stream ci 的权限)、工具与 CLI/安装包、环境访问(连通性、目标环境是否存在)、领域技能(仓库已有对应 skill 就用它的查询命令做验证)。

  2. 逐项实测,验证到链路深处。 只读操作:CLI 只读查询、凭据自检(如 gh auth status)、探活请求。worker 执行路径上的每个关键环节——API 接口、上传/下载、跨系统链路——都要实测到只读能验证的最深处:接口存在、参数可发、权限范围匹配。验证是轻量探针,不是实现:证明接口通、依赖可用即止,不写业务代码、不执行任务本身。不能凭“有凭据”推断“链路通畅”,也不能把链路环节推给 worker 当“接下来的工作”——worker 会撞上的墙都是现在的前置阻塞。记录证据:命令 + 关键输出。读得通不等于写得通——目标动作需要写权限而核查无法安全验证时,标“未验证(写权限需真实操作确认)”。跑不了的项如实标“未验证”,不得当作已通过;“足够继续”这类总结论必须逐项对应实测证据,无证据的乐观断言按未验证处理。

  3. 逐项归态。 每项依赖必须落到三态之一,不允许“以后再说”:

    • verified:实测通过,附证据。
    • resolved-now:缺的工具或配置现在补齐;涉及安装、写配置等环境改动时,先向用户说明并获同意。
    • spec'd:现在解决不了(需要申请权限、token),写进 spec 的“前置条件与授权”章节:具体缺什么、用户找谁申请什么、拿到后配置到哪里(哪个 profile 或环境变量)、worker 怎么用。spec 没有该章节就追加一节;spec 发布在 issue tracker 就写到 issue 里。
    • 需要用户决策才能归态的项,停下来问;拿到答复再归态,不跳过。
  4. 落盘报告。 产出三态清单表:依赖 / 用途 / 状态 / 证据或处置。spec'd 项同时汇总成“需要用户的支持”一节,逐项写明具体动作(申请哪个系统的什么权限或 token、提供什么凭据、授权哪次安装或一次最小写探针),让用户一次处理完,而不是 worker 跑起来后反复被打断。spec 可编辑就直接修订,否则作为 issue 评论或独立文件持久化——报告只留在聊天里等于没做,后续 worker 看不到。验证中发现仓库文档或 spec 与实测不符——漏记参数、过期接口、错误的配置说明——一并修正并提交:这是实测换来的事实修正,不回写,下一个 worker 照着错文档还会踩同一个坑。

完成标准

每项依赖都处于三态之一,且报告已持久化;需要用户支持的项已写明具体动作。仍有无法归态的项时明确列出交用户决定,不静默通过。

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.

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. today Changed · +2 lines 23cc329d000b
  2. 5d ago First seen · 25 lines · 36 tokens per session scan A 21943d78ed7f

Subscribe to this mod's changes

preflight is a skill published in the GitHub repository hxy91819/mason-skills (2 stars, last pushed today), licensed MIT. It adds 36 tokens to every session and 1,115 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 2026-09-07.

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