# subject-line-lab

This skill studies past email campaigns in a connected sending platform and suggests subject lines for the next one. Use it to shape ideas around your own audience’s results.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · ★ 111
- Author: Cogny AI
- License: not stated · policy=link-only · description only; the file stays with the author
- Source: https://github.com/cognyai/claude-code-marketing-skills/tree/HEAD/skills/subject-line-lab/SKILL.md
- Updated: 2026-10-12
- HTML: https://affpapa.org/en/nevibecode/skills/cogny-ai-subject-line-lab

## What it does

The skill reviews previous sends and looks for subject-line traits associated with opens among your subscribers. It then drafts candidates for a new campaign; you can include the campaign topic when you invoke it.

It requires Cogny MCP and a connected email platform such as Klaviyo, Mailchimp, Brevo, or Braze. The analysis depends on campaign data being available through Cogny, so connect the service before running the skill.

Install it with `npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a claude-code`. The skill file is placed at `~/.claude/skills/subject-line-lab/SKILL.md`.

## Requirements
- Works with: Salesforce

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/subject-line-lab/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/subject-line-lab/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/subject-line-lab/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/subject-line-lab/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install cognyai/claude-code-marketing-skills subject-line-lab
```

2. **Manually: put the files in place**
- File: `.github/skills/subject-line-lab/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/cognyai/claude-code-marketing-skills --path skills/subject-line-lab
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/subject-line-lab/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/cognyai/claude-code-marketing-skills/tree/HEAD/skills/subject-line-lab/SKILL.md

## When to use it
- identify subject-line traits associated with opens in past campaigns
- draft subject lines for an upcoming email campaign
- use previous campaign results to guide new subject-line ideas

## Example prompts
- Review my previous email campaigns and suggest subject lines for the next send.
- Suggest subject lines for a Black Friday launch campaign.

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## Other versions with the same name
- [subject-line-lab · aaron-he-zhu](https://affpapa.org/en/nevibecode/skills/subject-line-lab.md) — 1000 installs

From the same set: [cognyai/claude-code-marketing-skills](https://affpapa.org/en/nevibecode/by/cognyai/claude-code-marketing-skills.md) — 38 cards

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