End-of-Article CTA Designer
samber/cc-skills
Interviews you about objective, audience and context, then designs an end-of-article call to action with copy, placement, A/B test plan and accessibility check.
A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once.
Install Newsletter Engine
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install revfactory/harness-100 newsletter-engine --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .claude/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .claude/skills/newsletter-engine && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .claude/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engineType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install revfactory/harness-100 newsletter-engine --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .agents/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .agents/skills/newsletter-engine && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .agents/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install revfactory/harness-100 newsletter-engine --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .cursor/skills/newsletter-engine && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .cursor/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/revfactory/harness-100.git --path en/03-newsletter-engine/.claude/skills/newsletter-engine--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install revfactory/harness-100 newsletter-engine --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .gemini/skills/newsletter-engine && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .gemini/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install revfactory/harness-100 newsletter-engineInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .github/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .github/skills/newsletter-engine && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .github/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add revfactory/harness-100 --skill newsletter-engine -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install revfactory/harness-100 newsletter-engine --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/revfactory/harness-100.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/en/03-newsletter-engine/.claude/skills/newsletter-engine .opencode/skills/newsletter-engine && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "newsletter-engine" agent skill from https://github.com/revfactory/harness-100/tree/main/en/03-newsletter-engine/.claude/skills/newsletter-engine into .opencode/skills/newsletter-engine/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "newsletter-engine", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
newsletter-engine- GitHub stars
- 1.3k
- Token cost
- ~1.8k tokens
- SKILL.md length
- 699 words
- Files
- 1
- Skills in repo
- 464
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once.
- Works in 3 steps: Preparation (Performed directly by the… → Team Assembly and Execution → Integration and Final Deliverables
- Requests like write a newsletter
- SKILL.md covers Execution Mode, Agent Roster, Workflow and Scope-Based Modes, plus 4 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Newsletter Engine is an agent skill from revfactory/harness-100. A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once. Use this skill for requests like 'write a newsletter,' 'newsletter planning,' 'email newsletter,' 'newsletter curation,' 'newsletter A/B test,' 'subscriber email,' 'weekly newsletter,' 'newsletter send optimization,' and other newsletter production tasks. Also supports editing and optimization when existing content is provided. Note: email sending system…
Its SKILL.md is about 1.8k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Writing & Content, covering Newsletters and A/B testing. It works with Mailchimp. The licence is Apache-2.0.
When your agent uses it
- Requests like write a newsletter
- Newsletter planning
- Email newsletter
- Newsletter curation
Example prompts
- “write a newsletter,”
- “newsletter planning,”
- “email newsletter,”
- “/newsletter-engine”
Workflow steps
3 steps, taken from the step headings in SKILL.md.
What it can do on your machine
Read from SKILL.md and the folder at commit 8e8d35c. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Newsletter Engine loads about 1.8k tokens when it runs. Until then it costs about 168 tokens; SKILL.md has 699 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from revfactory/harness-100 at commit 8e8d35c, republished under its Apache-2.0 licence (© revfactory). 699 words, ~1,828 tokens.
Download SKILL.mdSave it as
.claude/skills/newsletter-engine/SKILL.md (or your agent's skills folder).- name
- newsletter-engine
- description
- A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once. Use this skill for requests like 'write a newsletter,' 'newsletter planning,' 'email newsletter,' 'newsletter curation,' 'newsletter A/B test,' 'subscriber email,' 'weekly newsletter,' 'newsletter send optimization,' and other newsletter production tasks. Also supports editing and optimization when existing content is provided. Note: email sending system (Mailchimp, ConvertKit) API integration, subscriber database management, and actual A/B test execution are outside this skill's scope.
Newsletter Engine — Full Newsletter Production Pipeline
An agent team collaborates to produce newsletters through the pipeline of curation → writing → A/B testing → editing → publishing, all at once.
Execution Mode
Agent Team — 5 members communicate directly via SendMessage and cross-validate each other's work.
Agent Roster
| Agent | File | Role | Type |
|---|---|---|---|
| curator | .claude/agents/curator.md | Source collection, trend analysis, content selection | general-purpose |
| copywriter | .claude/agents/copywriter.md | Headlines, body copy, CTA writing | general-purpose |
| analyst | .claude/agents/analyst.md | A/B test design, send optimization | general-purpose |
| editor-in-chief | .claude/agents/editor-in-chief.md | Tone consistency, final editing | general-purpose |
| quality-reviewer | .claude/agents/quality-reviewer.md | Cross-validation, consistency checks | general-purpose |
Workflow
Phase 1: Preparation (Performed directly by the orchestrator)
- Extract from user input:
- Topic/Theme: The subject the newsletter will cover
- Newsletter Info (optional): Brand tone, subscriber count, publication frequency
- Target Reader (optional): Subscriber characteristics, interests
- Constraints (optional): Length, specific section requirements
- Existing Files (optional): Content, previous issues, etc. provided by the user
- Create the
_workspace/directory at the project root - Organize the input and save it as
_workspace/00_input.md - If existing files are provided, copy them to
_workspace/and skip the corresponding phase - Determine the execution mode based on request scope
Phase 2: Team Assembly and Execution
| Order | Task | Owner | Depends On | Deliverable |
|---|---|---|---|---|
| 1 | Content curation | curator | None | _workspace/01_curation_brief.md |
| 2 | Newsletter writing | copywriter | Task 1 | _workspace/02_newsletter_draft.md |
| 3 | A/B test design | analyst | Tasks 1, 2 | _workspace/03_ab_test_plan.md |
| 4 | Final editing | editor-in-chief | Tasks 2, 3 | _workspace/04_editorial_final.md |
| 5 | Quality review | quality-reviewer | Tasks 2, 3, 4 | _workspace/05_review_report.md |
Inter-agent communication flow:
- curator complete → deliver angles & content to copywriter, trending keywords to analyst
- copywriter complete → deliver A/B variant materials to analyst, draft to editor-in-chief
- analyst complete → deliver send optimization & A/B recommendations to editor-in-chief
- editor-in-chief complete → deliver final version to quality-reviewer
- reviewer cross-validates all deliverables. On 🔴 Must Fix: request revision → rework → re-validate (up to 2 rounds)
Phase 3: Integration and Final Deliverables
- Verify all files in
_workspace/ - Confirm all 🔴 Must Fix items have been addressed
- Report the final summary to the user:
- Curation Brief —
01_curation_brief.md - Newsletter Draft —
02_newsletter_draft.md - A/B Test Plan —
03_ab_test_plan.md - Editor-in-Chief Final —
04_editorial_final.md - Review Report —
05_review_report.md
- Curation Brief —
Scope-Based Modes
| User Request Pattern | Execution Mode | Agents Deployed |
|---|---|---|
| "Plan a newsletter," "full production" | Full Pipeline | All 5 |
| "Just write the newsletter copy" | Copy Mode | curator + copywriter + quality-reviewer |
| "Make a newsletter from this content" (existing file) | Edit Mode | copywriter + editor-in-chief + quality-reviewer |
| "Design an A/B test" (existing newsletter) | Analysis Mode | analyst + quality-reviewer |
| "Review this newsletter" | Review Mode | quality-reviewer only |
Using Existing Files: If the user provides content or a previous newsletter, copy it to the appropriate location in _workspace/ and skip that phase.
Show full SKILL.md (285 more words)Show less
Data Transfer Protocol
| Strategy | Method | Purpose |
|---|---|---|
| File-based | _workspace/ directory | Primary deliverable storage and sharing |
| Message-based | SendMessage | Real-time key information transfer, revision requests |
| Task-based | TaskCreate/TaskUpdate | Progress tracking, dependency management |
File naming convention: {order}_{deliverable}.{extension}
Error Handling
| Error Type | Strategy |
|---|---|
| Web search failure | Curator works from user-provided materials, notes "real-time data not reflected" |
| Brand tone unclear | Apply default tone (professional + friendly), editor-in-chief recommends tone refinement after first issue |
| Agent failure | Retry once → if still failing, proceed without that deliverable, note omission in review report |
| 🔴 found in review | Request revision from responsible agent → rework → re-validate (up to 2 rounds) |
Test Scenarios
Happy Path
Prompt: "Create a weekly newsletter covering AI industry trends. Target audience: developers. Tone: professional with wit" Expected Results:
- Curation: 5+ latest AI articles, trend analysis, recommended resources
- Copy: Subject line (A/B 2 variants), preheader, intro + main story + sub stories + resources + closing
- Analysis: 2 A/B tests (subject line, CTA), send time recommendations, performance forecast
- Editorial: Tone review, legal check, final version
- Review: All consistency matrix items verified
Existing File Flow
Prompt: "Make a newsletter from this collection of articles" + content file attached Expected Results:
- Existing content organized into
_workspace/01_curation_brief.md - Edit Mode: copywriter + editor-in-chief + quality-reviewer deployed
- curator skipped
Error Flow
Prompt: "Just design A/B tests for this newsletter subject line" Expected Results:
- Switch to Analysis Mode (analyst + quality-reviewer)
- No newsletter body exists, so analyst proposes subject-line-pattern-based A/B variants
- Review report notes "body copy/curation not generated"
Agent Extension Skills
Each agent leverages the following extension skills to enhance deliverable quality:
| Agent | Extension Skill | Knowledge Provided |
|---|---|---|
| copywriter | /email-copywriting | CURVE subject line framework, CTA design, F-pattern body structure |
| analyst, curator | /audience-segmentation | BEAR segmentation model, send time optimization, welcome series |
| editor-in-chief, analyst | /deliverability-optimization | Spam filter avoidance, Gmail Promotions tab strategies, legal compliance |
© revfactory, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in en/03-newsletter-engine/.claude/skills/newsletter-engine of revfactory/harness-100.
Open the folder on GitHubat commit 8e8d35c
Compare with similar skills
Newsletter Engine next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Newsletter Engine this skillrevfactory/harness-100 | 1.3k | — | ~1.8k | Automated safety check: Pass | Apache-2.0 | |
| End-of-Article CTA Designersamber/cc-skills | 228 | — | ~3.1k | Automated safety check: Pass | MIT | |
| Email NewsletterVarnan-Tech/opendirectory | 674 | — | ~4.4k | Automated safety check: Pass | MIT | |
| Linkedin Post Experimentationhashgraph-online/awesome-codex-plugins | 1.3k | — | ~587 | Automated safety check: Pass | MIT | |
| Subject Line Labcognyai/claude-code-marketing-skills | 104 | — | ~2k | Automated safety check: Notes | None | |
| Internal Communications Writeranthropics/skills | 180k | 38 repos | ~378 | Automated safety check: Pass | Apache-2.0 |
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Related
Works with
Categories
Questions about Newsletter Engine
What does Newsletter Engine do?
A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once. Newsletter Engine is an agent skill from revfactory/harness-100. A full production pipeline where an agent team collaborates to generate newsletter content — curation, writing, A/B testing, and send optimization — all at once.
When should I use Newsletter Engine?
Newsletter Engine fits situations like: requests like write a newsletter; newsletter planning; email newsletter; newsletter curation.
How do I install Newsletter Engine in Claude Code?
Run `npx skills add revfactory/harness-100 --skill newsletter-engine -a claude-code`. Or copy the skill folder (en/03-newsletter-engine/.claude/skills/newsletter-engine in revfactory/harness-100) into .claude/skills/newsletter-engine in your project. Claude Code loads it when a task matches its description.
How do I install Newsletter Engine in Codex?
Run `npx skills add revfactory/harness-100 --skill newsletter-engine -a codex`. Or copy the skill folder (en/03-newsletter-engine/.claude/skills/newsletter-engine in revfactory/harness-100) into .agents/skills/newsletter-engine in your project. Codex loads it when a task matches its description.
Can I use Newsletter Engine in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add revfactory/harness-100 --skill newsletter-engine -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/newsletter-engine, .gemini/skills/newsletter-engine, .github/skills/newsletter-engine and .opencode/skills/newsletter-engine in your project.
What does Newsletter Engine need to run?
SKILL.md names no scripts, command-line tools or credentials: Newsletter Engine is instructions for the agent only.
Does Newsletter Engine access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Newsletter Engine safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Newsletter Engine use?
Newsletter Engine is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Newsletter Engine use?
About 1.8k tokens (SKILL.md is roughly 7.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Newsletter Engine?
Skills that share tags, products or a category with Newsletter Engine: End-of-Article CTA Designer (samber/cc-skills, 228 stars), Email Newsletter (Varnan-Tech/opendirectory, 674 stars), Linkedin Post Experimentation (hashgraph-online/awesome-codex-plugins, 1.3k stars) and Subject Line Lab (cognyai/claude-code-marketing-skills, 104 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Newsletter Engine?
revfactory (a GitHub user) maintains it in revfactory/harness-100, which has 1,295 GitHub stars. The repository holds 464 skills in this directory. The repository was last updated on March 22, 2026.
Source: revfactory/harness-100 on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.