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 sanky369/vibe-building-skills --skill newslettergit clone --depth 1 https://github.com/sanky369/vibe-building-skillsWrote 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/sanky369/vibe-building-skills/newsletter)<a href="https://agentmods.dev/skills/sanky369/vibe-building-skills/newsletter"><img src="https://agentmods.dev/badge/skills/sanky369/vibe-building-skills/newsletter/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/sanky369/vibe-building-skills/newsletter"><img src="https://agentmods.dev/badge/skills/sanky369/vibe-building-skills/newsletter.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 | $0.00128 | $0.01903 |
| Opus 5 | $0.00064 | $0.00951 |
| Sonnet 5 | $0.00026 | $0.00381 |
| Haiku 4.5 | $0.00013 | $0.00190 |
Grade A, and why
newsletter 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 12d 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 — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Newsletter
Write newsletter issues that subscribers open, read, and reply to. A newsletter is a recurring relationship, not a broadcast: it must be consistent (same format and cadence every time), valuable (useful before promotional), and personal (sounds like one human wrote it to one human). Prime directive: the reader must finish the issue glad they opened it — value first, promotion never more than a postscript.
When to use / when not to
- Use for writing a newsletter issue, designing a new newsletter (format + cadence + template), or fixing a stale one (falling opens, no replies).
- If the user wants automated emails triggered by behavior (welcome series, launch, sales sequence), use
skills/marketing/email-sequences— a newsletter is a recurring broadcast, not an automation. - If the user has no list and no way to get subscribers, route to
skills/marketing/lead-magnetfirst. - If the source material is a blog post being adapted for many channels at once, use
skills/marketing/content-atomizer(it can hand the newsletter item back here).
Intake
Ask in one batch, only what's missing:
- Audience and list — who subscribes, roughly how many, and what they signed up expecting.
- This issue's raw material — a story, lesson, link roundup, data point, or recent piece of content. If nothing, ask for one recent professional observation or lesson; there is always one.
- Voice — existing issues or a brand-voice guide to match (use
skills/marketing/brand-voiceoutput if it exists). - Goal — pure relationship-building, or is there something to softly promote?
If the user is starting a newsletter from scratch, also ask what they can sustain: writing capacity and how much source material their work naturally generates. Otherwise infer format and cadence from past issues. If enough is known, state assumptions and draft — don't stall.
Workflow
1. If new: lock the format and cadence (the Blueprint)
Pick one primary format by decision rule — the user can guest-star other formats occasionally, but the flagship format is what subscribers learn to expect:
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.
- 12d ago First seen · 124 lines · 128 tokens per session scan A 06be9750ef0c
newsletter is a skill published in the GitHub repository sanky369/vibe-building-skills (30 stars, last pushed 2mo ago), licensed MIT. It adds 128 tokens to every session and 1,903 once invoked, about $0.0006 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 2026-08-30.
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skill-curator
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git-workflow
A guide for handling Git repository work safely, including status checks, branches, commits, pushes, pull requests, and rebasing. Git is a version-control system that records code changes and coordinates work between developers.
zh-readme
A tool for writing README files in Chinese after first examining a software project. A README is the main guide visitors see when they open a code repository.
env-manager
An environment-variable manager for project settings stored outside the code, often in .env files. It checks variable definitions and usage while keeping secret values out of reports and terminal output.