Subject line writer
Give it your email and audience. Get subject lines in several angles that earn opens without losing clarity.
Subject line writer is a free AI skill for the job "Write ad copy". Give the instructions to an AI assistant that supports the required files and tools, then review its output.
Free · No account · CC BY 4.0 licence · Made by sickn33 · Level: beginner · Thinking: low
Made by sickn33. See the original on GitHub; we copied it as it is, with its licence.
What it does
Email subject lines in several angles, each built to earn an open without tricking the reader. You pick the one that fits your message and your audience. You give the email, who gets it, and where it sits in a sequence. The skill sets the plan first, using a decision matrix that weighs position in the sequence, how warm the audience is and whether people read on a phone. It then writes options, each using honest curiosity or a clear promise. It checks every line against a list of failure modes, such as clickbait and misleading claims, and against ethical guardrails. A final quality check trims the set.
You give it
- The email or its main point
- Who receives it and how warm they are
- Where it sits in the sequence (optional)
- Your brand voice (optional)
- Brand brain (optional)
You get
- Several subject lines in different angles
- A note on why each might work
- Checks for clickbait or misleading wording
- A suggested pick to test first
Use it when
- You wrote the email but the subject line is a blank.
- Your opens are low and you want to test new angles.
- You send a sequence and each email needs a line that fits its place.
- You write push notifications and have a few words to work with.
How to use it
- Add it to your AI once: download it and add the folder to Claude, ChatGPT or Codex as a skill.
- Ask for the job in your own words. Your AI opens the skill when it fits.