Email Variants

Variants allow you to A/B test different email approaches within a single campaign. Each variant has its own subject line, content, and distribution percentage.

You can create up to 4 variants per campaign. Leads are randomly assigned to variants based on distribution percentages when the campaign launches.

Campaign Status and Variant Updates

Variants can be updated on both DRAFT and PAUSED campaigns via PUT /campaigns/{campaign_id}, but the behavior differs:

Status	Behavior	Use Case
DRAFT	Replaces all variants	Initial campaign setup, full content rewrite
PAUSED	Smart merge by variant name	Update copy on existing campaigns without losing analytics

When updating variants on a PAUSED campaign:

Existing variants are matched by variant_name and updated in place (preserving IDs and analytics)
New variant names are created
Variant names omitted from the request are deleted

ACTIVE campaigns must be paused first before updating variants. Use POST /campaigns/{campaign_id}/pause to pause, then update, then POST /campaigns/{campaign_id}/activate to resume.

Configuring Variants

Variants are provided in the variants array when updating a campaign via PUT /api/public/v1/campaigns/{campaign_id}:

Python
JavaScript

import requests

response = requests.put(
    f"{base_url}/api/public/v1/campaigns/{campaign_id}",
    headers={"X-API-Key": api_key},
    json={
        "variants": [
            {
                "variant_name": "A",
                "variant_label": "Direct Approach",
                "subject_template": "Quick question about {{company}}",
                "email_content": "Hi {{first_name}},\n\nI noticed {{company}} is expanding. I'd love to share how we've helped similar companies.\n\nBest,\nJohn",
                "distribution_percent": 50
            },
            {
                "variant_name": "B",
                "variant_label": "Soft Introduction",
                "subject_template": "Introduction - {{company}}",
                "email_content": "Hi {{first_name}},\n\nI hope this finds you well. I wanted to introduce our company and see if there's an opportunity to collaborate.\n\nBest,\nJohn Smith",
                "distribution_percent": 50
            }
        ]
    }
)

const response = await fetch(`${baseUrl}/api/public/v1/campaigns/${campaignId}`, {
  method: "PUT",
  headers: {
    "X-API-Key": apiKey,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    variants: [
      {
        variant_name: "A",
        variant_label: "Direct Approach",
        subject_template: "Quick question about {{company}}",
        email_content: "Hi {{first_name}},\n\n...",
        distribution_percent: 50
      },
      {
        variant_name: "B",
        variant_label: "Soft Introduction",
        subject_template: "Introduction - {{company}}",
        email_content: "Hi {{first_name}},\n\n...",
        distribution_percent: 50
      }
    ]
  })
});

Variant Fields

Field	Type	Required	Description
`variant_name`	string	Yes	Unique identifier (A, B, C, D). Only letters allowed. Automatically uppercased.
`subject_template`	string	Yes	Subject line with personalization. Max 500 characters.
`email_content`	string	Yes	Email body content. Max 100,000 characters. Must be at least 10 characters (enforced at service layer). Supports Liquid templating.
`distribution_percent`	int	Yes	Percentage of leads for this variant (0-100). All must sum to 100.
`variant_label`	string	No	User-friendly label for analytics (max 100 chars).
`content_type`	string	No	Content mode: `plaintext`, `html`, or `raw_html`. Inferred from tracking setting if omitted.

Distribution percentages must sum to exactly 100%. If configuring variants, the API validates this on every update.

Subject Line Best Practices

Keep it concise — 40-60 characters for optimal display
Focus on value — Lead with a benefit or question
Personalize — Use {{first_name}} or {{company}}
Avoid spam triggers — No ALL CAPS, excessive punctuation, or words like free, urgent

Testing Different Approaches

Test one element at a time:

What to Test	Variant A	Variant B
Subject line	Direct question	Statement of value
Opening	Personal reference	Generic greeting
CTA	Calendar link	Reply request
Length	Short (3-4 lines)	Detailed (10-15 lines)

Compare variant performance after 7-14 days to reach statistical significance.

Next Steps

Follow-up Sequences

Set up automated follow-up emails.

Personalization

Use variables and conditionals for personalized content.

Getting Started

Authentication

Campaigns

Sender Accounts

Domains

Leads

Replies

Analytics

Reference

Compliance

Campaign Status and Variant Updates

Configuring Variants

Variant Fields

Subject Line Best Practices

Testing Different Approaches

Next Steps

Follow-up Sequences

Personalization

​Campaign Status and Variant Updates

​Configuring Variants

​Variant Fields

​Subject Line Best Practices

​Testing Different Approaches

​Next Steps

Follow-up Sequences

Personalization

Campaign Status and Variant Updates

Configuring Variants

Variant Fields

Subject Line Best Practices

Testing Different Approaches

Next Steps