Fill Smartlead's {{first_line}} variable for an entire campaign
Smartlead sends beautifully — it just doesn't write your openers. ColdOpen turns your lead CSV into the same CSV plus a first_line column, ready to map as a custom variable.
Spintax isn't personalization
Rotating 'Hope you're well' variants doesn't move reply rate. A line about the prospect's actual company does.
Built-in AI credits add up
Per-email AI pricing punishes volume senders. With your own API key a thousand lines costs about thirty cents.
Manual research doesn't scale past 50 leads
Five minutes of tab-switching per lead is 40 hours per thousand. ColdOpen does the list while you build the sequence.
How it works
Export your Smartlead lead list (or the source CSV you were about to import)
Paste it into ColdOpen and generate first lines
Import the exported CSV into Smartlead
Map first_line to a custom variable and reference {{first_line}} in your template
Example output
Tom Reddy · Parcelbase · parcelbase.io
“Parcelbase quoting landed cost at checkout kills the surprise-duties problem most cross-border shops still just apologize for.”
Common questions
Does the export format work with Smartlead imports?
Yes — it's your original CSV with one extra column, so every field you already mapped keeps working.
Can I regenerate lines I don't like?
Re-run any list with a different tone preset; lines regenerate fresh each run.
What does it cost?
First 10 lines free, then $19 once for unlimited. You bring your own OpenAI or Anthropic key, which stays in your browser and costs you fractions of a cent per line.
Run your next list through it
10 free lines, no signup, two minutes end to end.