Create Sequence Variant

Add an A/B variant to a sequence step. The campaign must not be active.

POSThttps://api.foxreach.io/api/v1/campaigns/{campaign_id}/sequences/{sequence_id}/variants

Requires an API key with the write scope.

Add at least two variants to a step to run an A/B test. Subject and body support variables and spin syntax; invalid spin syntax is refused.

Path Parameters#

campaign_idstringpathrequired

The campaign.

sequence_idstringpathrequired

The sequence step.

Body Parameters#

subjectstringbodyrequired

Subject line, up to 500 characters.

bodystringbodyrequired

Body, up to 200,000 characters.

labelstringbody

Unique within the step, up to 10 characters. Default A.

weightintegerbody

Share of sends relative to the other variants, 1 to 1000. Default 1.

sendAsHtmlbooleanbody

Send as HTML. Default false.

Response#

dataobject

Show Variant object

idstring

Variant identifier.

sequenceIdstring

The step it belongs to.

labelstring

Unique within the step, for example A.

subjectstring

Subject line. Supports variables and spin syntax.

bodystring

Body. Supports variables and spin syntax.

weightinteger

Share of sends relative to the other variants.

sendAsHtmlboolean

Sent as HTML.

createdAtstring

ISO 8601 timestamp.

updatedAtstring

ISO 8601 timestamp.

Errors#

Status	Description
`401`	Missing, invalid, revoked or expired API key
`403`	API key does not have the required scope: `write`
`400`	The campaign is active (pause it first), the spin syntax is invalid, or the label is already used on this step
`404`	Campaign or sequence step not found in this workspace
`422`	A field is out of range, for example a label longer than 10 characters

Rate Limit#

120 requests per minute, shared by every write call in your workspace. Fixed 60-second window.
Every response includes X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset (unix epoch seconds) and X-RateLimit-Bucket (write).
A 429 response includes a Retry-After header (seconds until the bucket resets).

For client-side patterns (Retry-After, exponential backoff, monitoring X-RateLimit-Remaining), see Rate Limiting.

Request

cURL

curl -X POST "https://api.foxreach.io/api/v1/campaigns/cmcamp1/sequences/cmseq1/variants" \
  -H "X-API-Key: otr_your_key" \
  -H "Content-Type: application/json" \
  -d '{"label": "B", "subject": "Quick idea for {{company}}", "body": "Hi {{firstName}}, ..."}'

Python SDK

from foxreach import FoxReach

client = FoxReach(api_key="otr_your_key")
from foxreach import VariantCreate

variant = client.campaigns.sequences.create_variant(
    "cmcamp1", "cmseq1", VariantCreate(label="B", subject="Quick idea for {{company}}", body="Hi {{firstName}}, ...")
)

TypeScript SDK

import { FoxReach } from "foxreach";

const client = new FoxReach({ apiKey: "otr_your_key" });
const variant = await client.campaigns.sequences.createVariant("cmcamp1", "cmseq1", {
  label: "B",
  subject: "Quick idea for {{company}}",
  body: "Hi {{firstName}}, ...",
});

Response

JSON

{
  "data": {
    "id": "cmvar1",
    "sequenceId": "cmseq1",
    "label": "B",
    "subject": "Quick idea for {{company}}",
    "body": "Hi {{firstName}}, ...",
    "weight": 1,
    "sendAsHtml": false,
    "createdAt": "2026-11-04T09:00:00",
    "updatedAt": "2026-11-04T09:00:00"
  }
}

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View as MarkdownLast updated November 4, 2026