newsletter

newsletter is a skill for Claude Code, Codex from OpenClaudia/openclaudia-skills. It costs 63 tokens per session (2,044 once invoked), scanned A, original, MIT.

A planning guide for creating, growing, and earning money from an email newsletter, including its content and subscriber strategy.

In plain words
What is it for?
Use it to plan newsletter content, write subject lines, improve engagement, grow subscribers, and develop sponsorship or other revenue approaches.
Why use it?
It helps address common newsletter problems such as weak subject lines, low engagement, slow subscriber growth, and unclear monetization.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

not rated 689repo +9 today A scan Socket: passSnyk: passSkillSpector: pass 63 tokens original MIT

Good fit Use it to plan newsletter content, write subject lines, improve engagement, grow subscribers, and develop sponsorship or other revenue approaches.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/openclaudia/openclaudia-skills/newsletter
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 OpenClaudia/openclaudia-skills --skill newsletter
Clone the repo
git clone --depth 1 https://github.com/OpenClaudia/openclaudia-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 newsletter

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

agentmods 80×15 button for newsletter

Your own site · 80×15
<a href="https://agentmods.dev/skills/openclaudia/openclaudia-skills/newsletter"><img src="https://agentmods.dev/badge/skills/openclaudia/openclaudia-skills/newsletter.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,044 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. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk pass 16 Feb 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00063 $0.02044
Opus 5 $0.00032 $0.01022
Sonnet 5 $0.00013 $0.00409
Haiku 4.5 $0.00006 $0.00204

Measured 13d ago against content hash ea1925e45417, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

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 13d 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.

skills/newsletter/SKILL.md · 233 lines

How it starts

The opening of the file, as written. The whole thing — 233 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Newsletter Growth Skill

You are a newsletter growth strategist. Help plan content, grow subscribers, improve engagement, and monetize newsletters.

Newsletter Fundamentals

Subject Lines

Formulas that work:

Formula Example Open Rate Impact
Number + Benefit "7 tools that saved me 10hrs/week" High
Question "Are you making this SEO mistake?" High
How-to + Specific "How I grew to 10K subs in 6 months" High
Curiosity gap "The strategy nobody talks about" Medium-High
News/Urgency "Breaking: Google just changed this" Medium
Personal/Story "I almost quit last week" Medium
List/Roundup "This week: 5 links worth your time" Medium

Rules:

  • 30-50 characters optimal (mobile-friendly)
  • Preview text is equally important — extend the subject line, don't repeat it
  • Personalization tokens ({first_name}) lift open rates 5-10%
  • Avoid spam triggers: FREE, URGENT, ALL CAPS, excessive punctuation
  • A/B test subjects on every send

Content Structure

The 3 newsletter archetypes:

  1. Curated — Links + commentary (e.g., TLDR, Morning Brew)

    • 5-10 links with 2-3 sentence commentary each
    • Fastest to produce, requires good sources
    • Best for: News, industry updates, trends
  2. Original — Single essay/article (e.g., Lenny's Newsletter, Stratechery)

    • 1,000-2,500 words of original analysis
    • Highest authority building, most effort
    • Best for: Thought leadership, premium/paid
  3. Hybrid — Original intro + curated links (most common)

    • 200-500 word original section + 3-5 curated links
    • Good balance of effort and value
    • Best for: Most newsletters starting out

Frequency

Frequency Pros Cons Best For
Daily Habit-forming, high touch Burnout risk, high churn News, curated
2-3x/week Good balance Moderate effort Curated, hybrid
Weekly Most sustainable Slower growth Original, hybrid
Biweekly Low effort Easy to forget Premium, long-form
Monthly Minimal time Low engagement Company updates

Read the full file on GitHub · 233 lines

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. 13d ago First seen · 233 lines · 63 tokens per session scan A ea1925e45417

Subscribe to this mod's changes

newsletter is a skill published in the GitHub repository OpenClaudia/openclaudia-skills (689 stars, last pushed today), licensed MIT. It adds 63 tokens to every session and 2,044 once invoked, about $0.0003 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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