Twain generates a unique subject line for every lead automatically. No manual prompting needed. They're included in the export alongside your message steps.
How subject lines are generated
Twain applies a framework with dynamic placeholders (for example: a recent insight about the lead's company) to each subject line. The framework stays the same across your campaign, but the actual text changes per person based on the deep research Twain finds on them.
You can adjust the framework at any time via the chat panel or in the Twain UI. For example: "Use a short question as the subject line" or "Make it a one-word topic." Twain will apply the updated structure going forward.
How to export subject lines
Subject lines export as custom variables alongside your message steps. The exact export UI depends on the tool you're connecting to, so check the integration guide for your sequencer if you're not sure where to find the mapping step.
In general: look for the subject line fields in the export or mapping screen, make sure the variable names match what your sequencer expects, and toggle off any subject lines you don't want to include.
💡 Even though Twain generates a subject line for every step, we recommend threading your follow-up emails (leaving the subject line blank after Step 1) for better deliverability. Most sequencers support this natively.
A/B testing subject lines
The cleanest way to A/B test is to split your lead list into two campaigns and give each a different subject line framework via the chat panel. Run both in parallel and compare open rates.
Can I use variables like {nearest city} in subject lines?
No. Twain doesn't support placeholder variables of that type in subject lines. If you need location-based or formula-driven subject lines, build that in Clay or your sequencer before export.