subject-line-lab · cognyai — Claude Code skill for email subjects
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.
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a claude-codeWhat subject-line-lab 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.
What it helps with
- 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 for the agent
- Review my previous email campaigns and suggest subject lines for the next send.
- Suggest subject lines for a Black Friday launch campaign.
How to install subject-line-lab
1Skills CLI (Vercel)
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a claude-code2Manually: put the files in place
~/.claude/skills/subject-line-lab/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/subject-line-lab/
1Skills CLI (Vercel)
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a codex2Manually: put the files in place
.agents/skills/subject-line-lab/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a cursor2Manually: put the files in place
.cursor/skills/subject-line-lab/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install cognyai/claude-code-marketing-skills subject-line-lab2Manually: put the files in place
.github/skills/subject-line-lab/SKILL.md1Skills CLI (Vercel)
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a gemini-cli2Platform CLI
gemini skills install https://github.com/cognyai/claude-code-marketing-skills --path skills/subject-line-labManually: put the files in place
.devin/skills/subject-line-lab/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about subject-line-lab
How do I install subject-line-lab in Claude Code?
Run npx skills add cognyai/claude-code-marketing-skills --skill subject-line-lab -a claude-code. The skill file is at ~/.claude/skills/subject-line-lab/SKILL.md.
What does subject-line-lab do?
It examines past email subject lines alongside open results, then drafts candidates for another campaign.
What does subject-line-lab need to run?
It needs Cogny MCP and a connected email platform, such as Klaviyo or Mailchimp. Campaign data must be accessible through that connection.
Similar skills
All skills for Marketing and content →subject-line-lab by other authors comes first.
