Send transactional email
curl --request POST \
--url https://app.loops.so/api/v1/transactional \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"email": "<string>",
"transactionalId": "<string>",
"addToAudience": true,
"dataVariables": {},
"attachments": [
{
"filename": "<string>",
"contentType": "<string>",
"data": "<string>"
}
]
}
'{
"success": true
}
Transactional emails
Send transactional email
Send a transactional email to a contact.
POST
/
v1
/
transactional
Send transactional email
curl --request POST \
--url https://app.loops.so/api/v1/transactional \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"email": "<string>",
"transactionalId": "<string>",
"addToAudience": true,
"dataVariables": {},
"attachments": [
{
"filename": "<string>",
"contentType": "<string>",
"data": "<string>"
}
]
}
'{
"success": true
}
Documentation Index
Fetch the complete documentation index at: https://loops.so/docs/llms.txt
Use this file to discover all available pages before exploring further.
Request
Body
The email address of the recipient.
The ID of the transactional email to send.
If
true, a contact will be created in your audience using the email value
(if a matching contact doesn’t already exist).An object containing data as defined by the data variables added to the
transactional email template. Values can be of type
If you have added optional data variables to your email, you can exclude them from the
If you have added an array data variable to your email, make sure to include an array matching the data variables you added to your array block.
string or number.If you have added optional data variables to your email, you can exclude them from the
dataVariables object or set the value to "".If you have added an array data variable to your email, make sure to include an array matching the data variables you added to your array block.
Please contact support to enable attachments on your account before using them with the API.
To set dynamic Subject, From, Reply to, CC, BCC email header fields, add data
variables to those fields in the editor, then include data for each variable
in the API request. Read our transactional email
guide for more details.
Headers
Optionally send an idempotency key to avoid duplicate requests. The value
should be a string of up to 100 characters and should be unique for each
request. We recommend using V4 UUIDs or some other method with enough
guaranteed entropy to avoid collisions during a 24 hour window. The endpoint
will return a
409 Conflict response if the idempotency key has been used in
the previous 24 hours.Response
Success
Error
If the transactional email is not found, a404 Not Found will be returned.
If you send an idempotency key which has already been used in the previous 24 hours, a 409 Conflict response will be returned.
All other errors will be 400 Bad Request.
Deprecated fields will be removed in the future so avoid using them in your
code.
{
"success": true
}
Last modified on May 5, 2026
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