Catch up an automation's missed run

POST

/api/v3/automations/{automationUniqueId}/actions/run

const url = 'https://api.tryletterhead.com/api/v3/automations/example/actions/run';
const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}

curl --request POST \
  --url https://api.tryletterhead.com/api/v3/automations/example/actions/run \
  --header 'Authorization: Bearer <token>'

Run this automation’s real send chain on its own schedule, for the case where a scheduled run was missed. Unlike the trigger endpoint above, this does not send immediately — the run still respects the automation’s normal publication date and frequency, which may be hours away. The creators receive a test email first, and the automation is released back onto its normal schedule once the run is queued.

Nothing is sent by this call itself — the newsletter goes out at the automation’s own scheduled time. The response is 202 because the run is queued, not finished, when this answers.

Because of that, this endpoint is restricted to Letterhead staff: it authenticates as a signed-in user with a @tryletterhead.com or @whereby.us email address rather than a company API key, so it is not available to external integrations.

Authorizations

bearerAuth

Parameters

Path Parameters

automationUniqueId

required

string

The automation’s unique identifier.

Responses

202

202 Accepted

application/json

object

items

string

nullable

message

string

total

integer

Example

{
  "items": null,
  "message": "Automation is running now. Its newsletter is scheduled to send at Aug 26, 2026 2:32pm UTC, and a test email is on its way to the creators.",
  "total": 0
}

Still can’t find what you need? Contact support.