API documentation | API docs for agents | OpenAPI 3.1

custom

ark.send_custom_email

Sends a custom ARK TMS email from the organization sender with optional storage or inline attachments.

Availability: Expanded preview
Scopes: loads:write
ARK permissions: canViewLoads
Team visibility: Not entity-scoped
Idempotency-Key: Required for this write
Approval: No MCP approval on REST API-token calls
Rate limit: API credential and organization budgets

Parameters

Idempotency-Keyheaderstringrequired: Required for external write operations. Reuse the same key only for exact retries of the same request body.; min length: 1; max length: 200

Request body

tostring | array<string>required

ccstring | array<string>

bccstring | array<string>

subjectstring

default: ""; max length: 500

bodystring

default: ""; max length: 100000

htmlBodystring

max length: 250000

replyTostring | object

storageAttachmentsarray<object>

max items: 25

inlineAttachmentsarray<object>

max items: 10

Example request

Shell

curl -X POST 'https://arktms.com/api/v1/email/custom' \
  -H "Authorization: Bearer $ARK_API_TOKEN" \
  -H "Idempotency-Key: <unique-key>" \
  -H "Content-Type: application/json" \
  -d '{
  "to": "<to>"
}'

Success response

Sent custom email

objectstringrequired

okbooleanrequired

api_versionstringrequired

request_idstringrequired

dataobjectrequired

data.successbooleanrequired

data.messagestringrequired

data.deliveryModestring | nullrequired

one of: direct, queued, null

data.emailMessageIdstring | nullrequired

data.providerMessageIdstring | nullrequired

data.recipientsobjectrequired

data.subjectstringrequired

data.attachmentCountintegerrequired

min: 0

Errors

HTTP 400: Invalid request
HTTP 401: Authentication required
HTTP 403: Permission, scope, team, or entitlement denied
HTTP 404: Resource not found
HTTP 409: Idempotency conflict or in-progress retry
HTTP 413: Request exceeds the supported operation size
HTTP 502: External provider or worker queue could not be reached