Update an email message

curl --request POST \
  --url https://app.loops.so/api/v1/email-messages/{emailMessageId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "expectedRevisionId": "<string>",
  "subject": "<string>",
  "previewText": "<string>",
  "fromName": "<string>",
  "fromEmail": "<string>",
  "replyToEmail": "<string>",
  "ccEmail": "<string>",
  "bccEmail": "<string>",
  "languageCode": "<string>",
  "lmx": "<string>",
  "contactPropertiesFallbacks": {},
  "eventPropertiesFallbacks": {},
  "dataVariablesFallbacks": {}
}
'

import requests

url = "https://app.loops.so/api/v1/email-messages/{emailMessageId}"

payload = {
    "expectedRevisionId": "<string>",
    "subject": "<string>",
    "previewText": "<string>",
    "fromName": "<string>",
    "fromEmail": "<string>",
    "replyToEmail": "<string>",
    "ccEmail": "<string>",
    "bccEmail": "<string>",
    "languageCode": "<string>",
    "lmx": "<string>",
    "contactPropertiesFallbacks": {},
    "eventPropertiesFallbacks": {},
    "dataVariablesFallbacks": {}
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    expectedRevisionId: '<string>',
    subject: '<string>',
    previewText: '<string>',
    fromName: '<string>',
    fromEmail: '<string>',
    replyToEmail: '<string>',
    ccEmail: '<string>',
    bccEmail: '<string>',
    languageCode: '<string>',
    lmx: '<string>',
    contactPropertiesFallbacks: {},
    eventPropertiesFallbacks: {},
    dataVariablesFallbacks: {}
  })
};

fetch('https://app.loops.so/api/v1/email-messages/{emailMessageId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.loops.so/api/v1/email-messages/{emailMessageId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'expectedRevisionId' => '<string>',
    'subject' => '<string>',
    'previewText' => '<string>',
    'fromName' => '<string>',
    'fromEmail' => '<string>',
    'replyToEmail' => '<string>',
    'ccEmail' => '<string>',
    'bccEmail' => '<string>',
    'languageCode' => '<string>',
    'lmx' => '<string>',
    'contactPropertiesFallbacks' => [
        
    ],
    'eventPropertiesFallbacks' => [
        
    ],
    'dataVariablesFallbacks' => [
        
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.loops.so/api/v1/email-messages/{emailMessageId}"

	payload := strings.NewReader("{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://app.loops.so/api/v1/email-messages/{emailMessageId}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.loops.so/api/v1/email-messages/{emailMessageId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}"

response = http.request(request)
puts response.read_body

{
  "id": "<string>",
  "subject": "<string>",
  "previewText": "<string>",
  "fromName": "<string>",
  "fromEmail": "<string>",
  "replyToEmail": "<string>",
  "lmx": "<string>",
  "contentRevisionId": "<string>",
  "updatedAt": "2023-11-07T05:31:56Z",
  "campaignId": "<string>",
  "transactionalId": "<string>",
  "ccEmail": "<string>",
  "bccEmail": "<string>",
  "languageCode": "<string>",
  "contactPropertiesFallbacks": {},
  "eventPropertiesFallbacks": {},
  "dataVariablesFallbacks": {},
  "warnings": [
    {
      "rule": "<string>",
      "severity": "warning",
      "message": "<string>",
      "path": "<string>"
    }
  ]
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

POST

email-messages

{emailMessageId}

Update an email message

curl --request POST \
  --url https://app.loops.so/api/v1/email-messages/{emailMessageId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "expectedRevisionId": "<string>",
  "subject": "<string>",
  "previewText": "<string>",
  "fromName": "<string>",
  "fromEmail": "<string>",
  "replyToEmail": "<string>",
  "ccEmail": "<string>",
  "bccEmail": "<string>",
  "languageCode": "<string>",
  "lmx": "<string>",
  "contactPropertiesFallbacks": {},
  "eventPropertiesFallbacks": {},
  "dataVariablesFallbacks": {}
}
'

import requests

url = "https://app.loops.so/api/v1/email-messages/{emailMessageId}"

payload = {
    "expectedRevisionId": "<string>",
    "subject": "<string>",
    "previewText": "<string>",
    "fromName": "<string>",
    "fromEmail": "<string>",
    "replyToEmail": "<string>",
    "ccEmail": "<string>",
    "bccEmail": "<string>",
    "languageCode": "<string>",
    "lmx": "<string>",
    "contactPropertiesFallbacks": {},
    "eventPropertiesFallbacks": {},
    "dataVariablesFallbacks": {}
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    expectedRevisionId: '<string>',
    subject: '<string>',
    previewText: '<string>',
    fromName: '<string>',
    fromEmail: '<string>',
    replyToEmail: '<string>',
    ccEmail: '<string>',
    bccEmail: '<string>',
    languageCode: '<string>',
    lmx: '<string>',
    contactPropertiesFallbacks: {},
    eventPropertiesFallbacks: {},
    dataVariablesFallbacks: {}
  })
};

fetch('https://app.loops.so/api/v1/email-messages/{emailMessageId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://app.loops.so/api/v1/email-messages/{emailMessageId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'expectedRevisionId' => '<string>',
    'subject' => '<string>',
    'previewText' => '<string>',
    'fromName' => '<string>',
    'fromEmail' => '<string>',
    'replyToEmail' => '<string>',
    'ccEmail' => '<string>',
    'bccEmail' => '<string>',
    'languageCode' => '<string>',
    'lmx' => '<string>',
    'contactPropertiesFallbacks' => [
        
    ],
    'eventPropertiesFallbacks' => [
        
    ],
    'dataVariablesFallbacks' => [
        
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://app.loops.so/api/v1/email-messages/{emailMessageId}"

	payload := strings.NewReader("{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://app.loops.so/api/v1/email-messages/{emailMessageId}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://app.loops.so/api/v1/email-messages/{emailMessageId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"expectedRevisionId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"previewText\": \"<string>\",\n  \"fromName\": \"<string>\",\n  \"fromEmail\": \"<string>\",\n  \"replyToEmail\": \"<string>\",\n  \"ccEmail\": \"<string>\",\n  \"bccEmail\": \"<string>\",\n  \"languageCode\": \"<string>\",\n  \"lmx\": \"<string>\",\n  \"contactPropertiesFallbacks\": {},\n  \"eventPropertiesFallbacks\": {},\n  \"dataVariablesFallbacks\": {}\n}"

response = http.request(request)
puts response.read_body

{
  "id": "<string>",
  "subject": "<string>",
  "previewText": "<string>",
  "fromName": "<string>",
  "fromEmail": "<string>",
  "replyToEmail": "<string>",
  "lmx": "<string>",
  "contentRevisionId": "<string>",
  "updatedAt": "2023-11-07T05:31:56Z",
  "campaignId": "<string>",
  "transactionalId": "<string>",
  "ccEmail": "<string>",
  "bccEmail": "<string>",
  "languageCode": "<string>",
  "contactPropertiesFallbacks": {},
  "eventPropertiesFallbacks": {},
  "dataVariablesFallbacks": {},
  "warnings": [
    {
      "rule": "<string>",
      "severity": "warning",
      "message": "<string>",
      "path": "<string>"
    }
  ]
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

{
  "message": "<string>"
}

Supply expectedRevisionId matching the current contentRevisionId.

The campaign or transactional email that owns this email message must be in Draft status..

Authorizations

Authorization

string

header

required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Path Parameters

emailMessageId

string

required

The ID of the email message.

Body

application/json

expectedRevisionId

string

The contentRevisionId you last fetched, or the emailMessageContentRevisionId you received when creating the campaign.

subject

string

previewText

string

fromName

string

fromEmail

string

The sender username (without @ or domain). The team's sending domain is appended automatically.

replyToEmail

string

Reply-to email. Must be empty or a valid email address.

ccEmail

string

CC email address. Requires the team to have CC/BCC enabled.

bccEmail

string

BCC email address. Requires the team to have CC/BCC enabled.

languageCode

string

Language code for the email. Requires translation to be enabled for the team.

emailFormat

enum<string>

The rendering format of the email.

Available options:

styled,

plain

lmx

string

The email body serialized as LMX. Styles must be embedded in the LMX <Style /> tag.

contactPropertiesFallbacks

object

Fallback values for contact properties, keyed by property name. Per-key merge: a string value sets the fallback, a null value deletes it, and keys omitted from the map are left unchanged.

Show child attributes

eventPropertiesFallbacks

object

Fallback values for event properties, keyed by property name. Per-key merge: a string value sets the fallback, a null value deletes it, and keys omitted from the map are left unchanged.

Show child attributes

dataVariablesFallbacks

object

Fallback values for data variables, keyed by variable name. Per-key merge: a string value sets the fallback, a null value deletes it, and keys omitted from the map are left unchanged.

Show child attributes

Response

Email message updated.

string

required

The ID of the email message.

subject

string

required

The email subject.

previewText

string

required

The email preview text.

fromName

string

required

The email sender name.

fromEmail

string

required

The email sender email address.

replyToEmail

string

required

The email reply-to address.

emailFormat

enum<string>

required

The rendering format of the email.

Available options:

styled,

plain

lmx

string

required

The email body serialized as LMX.

contentRevisionId

string | null

required

The current content revision. Pass this as expectedRevisionId on your next update.

updatedAt

string<date-time>

required

campaignId

string

The campaign this email message belongs to. Present only when the message belongs to a campaign (mutually exclusive with transactionalId).

transactionalId

string

The transactional email this email message belongs to. Present only when the message belongs to a transactional email (mutually exclusive with campaignId).

ccEmail

string

The email CC address. Only present when set.

bccEmail

string

The email BCC address. Only present when set.

languageCode

string

Only present when set.

contactPropertiesFallbacks

object

Fallback values for contact properties. Only present when set.

Show child attributes

eventPropertiesFallbacks

object

Fallback values for event properties. Only present when set.

Show child attributes

dataVariablesFallbacks

object

Fallback values for data variables. Only present when set.

Show child attributes

warnings

object[]

Non-fatal issues raised while compiling the submitted LMX. Only present on update responses when warnings were produced.

Show child attributes

Last modified on July 20, 2026

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API

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Update an email message

Authorizations

Path Parameters

Body

Response