Schedule Campaign

Schedule or immediately send a campaign. The campaign must be in DRAFT status and fully configured (sender identity, audience, and variants with subject + content).

Endpoint

POST https://api.campaignlark.com/v1/campaigns/:id/schedule

Path Parameters

Parameter	Type	Required	Description
`id`	string	required	The campaign ID.

Request Body

Field	Type	Required	Description
`schedule_type`	string	required	`NOW` to send immediately, or `LATER` to schedule for a future time.
`scheduled_at`	string	required if `LATER`	ISO 8601 UTC timestamp. Must be in the future.

Sample Request — Send Now

POST https://api.campaignlark.com/v1/campaigns/64f1a2b3c4d5e6f7a8b9c0d1/schedule
Content-Type: application/json

{
  "schedule_type": "NOW"
}

Sample Request — Schedule for Later

POST https://api.campaignlark.com/v1/campaigns/64f1a2b3c4d5e6f7a8b9c0d1/schedule
Content-Type: application/json

{
  "schedule_type": "LATER",
  "scheduled_at": "2025-08-01T09:00:00Z"
}

Response

Success — `200 OK`

{
  "error": null,
  "data": {
    "id": "64f1a2b3c4d5e6f7a8b9c0d1",
    "status": "QUEUED",
    "scheduled_at": "2025-08-01T09:00:00Z"
  }
}

The status will be QUEUED for approved workspaces, or PREPROCESSING for workspaces that require review.

Errors

Status	Message	Cause
`400`	`Please provide a campaign ID.`	`id` path param is missing.
`400`	`Invalid request body.`	Request body could not be parsed.
`400`	`Invalid schedule type. Must be 'NOW' or 'LATER'.`	`schedule_type` is invalid.
`400`	`Scheduled date and time is required when schedule type is 'LATER'.`	`scheduled_at` is missing for `LATER` type.
`400`	`Invalid scheduled date format. Please provide a valid ISO 8601 UTC timestamp.`	`scheduled_at` is not valid RFC 3339.
`400`	`Scheduled date must be in the future.`	`scheduled_at` is in the past.
`400`	`We could not find the campaign you are looking for.`	Campaign not found.
`400`	`Only draft campaigns can be scheduled.`	Campaign is not in `DRAFT` status.
`400`	`Please configure a sender identity before scheduling the campaign.`	No sender identity configured.
`400`	`Please add at least one variant before scheduling the campaign.`	Campaign has no variants.
`400`	`A/B testing campaigns must have at least two variants before scheduling.`	A/B campaign has fewer than 2 variants.
`400`	`All variants must have a subject before scheduling the campaign.`	A variant is missing a subject.
`400`	`All variants must have email content before scheduling the campaign.`	A variant is missing body content.
`400`	`Please configure an audience before scheduling the campaign.`	No audience configured.

Endpoint​

Path Parameters​

Request Body​

Sample Request — Send Now​

Sample Request — Schedule for Later​

Response​

Success — 200 OK​

Errors​