Send Transactional Email

POST

api

transactional

send

curl --request POST \
  --url https://api.sequenzy.com/api/v1/transactional/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "to": [
    "<string>"
  ],
  "slug": "<string>",
  "templateId": "<string>",
  "subject": "<string>",
  "body": "<string>",
  "html": "<string>",
  "preview": "<string>",
  "variables": {},
  "subscriberExternalId": "<string>",
  "from": "<string>",
  "replyTo": "<string>",
  "attachments": [
    {}
  ]
}
'

import requests

url = "https://api.sequenzy.com/api/v1/transactional/send"

payload = {
    "to": ["<string>"],
    "slug": "<string>",
    "templateId": "<string>",
    "subject": "<string>",
    "body": "<string>",
    "html": "<string>",
    "preview": "<string>",
    "variables": {},
    "subscriberExternalId": "<string>",
    "from": "<string>",
    "replyTo": "<string>",
    "attachments": [{}]
}
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({
    to: ['<string>'],
    slug: '<string>',
    templateId: '<string>',
    subject: '<string>',
    body: JSON.stringify('<string>'),
    html: '<string>',
    preview: '<string>',
    variables: {},
    subscriberExternalId: '<string>',
    from: '<string>',
    replyTo: '<string>',
    attachments: [{}]
  })
};

fetch('https://api.sequenzy.com/api/v1/transactional/send', 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://api.sequenzy.com/api/v1/transactional/send",
  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([
    'to' => [
        '<string>'
    ],
    'slug' => '<string>',
    'templateId' => '<string>',
    'subject' => '<string>',
    'body' => '<string>',
    'html' => '<string>',
    'preview' => '<string>',
    'variables' => [
        
    ],
    'subscriberExternalId' => '<string>',
    'from' => '<string>',
    'replyTo' => '<string>',
    'attachments' => [
        [
                
        ]
    ]
  ]),
  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://api.sequenzy.com/api/v1/transactional/send"

	payload := strings.NewReader("{\n  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\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://api.sequenzy.com/api/v1/transactional/send")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.sequenzy.com/api/v1/transactional/send")

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  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\n}"

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

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "welcome",
    "name": "Welcome Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "password-reset",
    "name": "Password Reset"
  },
  "diagnostics": {
    "status": "warning",
    "message": "Email was queued. A required variable is missing and will render as an empty string.",
    "missingRequiredVariables": [
      {
        "name": "RESET_URL",
        "lookupName": "reset_url",
        "message": "Email was queued. Required variable \"RESET_URL\" is missing and will render as an empty string.",
        "usedIn": [
          {
            "surface": "block",
            "blockId": "reset-button",
            "blockType": "button",
            "field": "url"
          }
        ],
        "suggestions": ["resetpasswordlink"]
      }
    ],
    "unusedVariables": [
      {
        "name": "resetpasswordlink",
        "message": "Variable \"resetpasswordlink\" was provided but is not used by the email template.",
        "suggestions": ["reset_url"]
      }
    ]
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": ["user1@example.com", "user2@example.com"],
  "transactional": {
    "id": "txn_abc123",
    "slug": "invoice",
    "name": "Invoice Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com"
}

{
  "success": false,
  "error": "Either 'slug'/'templateId' OR both 'subject' and 'body'/'html' are required"
}

{
  "success": false,
  "error": "Transactional email \"welcome\" is disabled"
}

{
  "success": false,
  "error": "No sender profile configured. Please create a sender profile first."
}

{
  "success": false,
  "error": "Invalid attachments: Attachment[0]: Attachment must have either 'content' (Base64) or 'path' (URL)"
}

{
  "success": false,
  "error": "Attachment \"large-file.pdf\" exceeds maximum size of 40MB"
}

{
  "success": false,
  "error": "Total attachment size exceeds 40MB limit"
}

{
  "success": false,
  "error": "Transactional email with slug \"welcome\" not found"
}

{
  "success": false,
  "error": "Unauthorized"
}

{
  "success": false,
  "error": "Internal server error"
}

Send a transactional email. You can either use a saved template (by slug) or send custom content directly.

A successful response means the email was accepted for background processing. Transactional emails are not blocked by subscriber unsubscribe or double opt-in status. If a recipient is suppressed because of a hard bounce or spam complaint, the worker records the send as suppressed instead of delivering it. Use the returned emailSendId with the email-send details endpoint to inspect the final status and any provider failure reason.

Request Body

Recipients

string | string[]

required

Recipient email address(es). Can be a single email string or an array of up to 50 emails. All recipients will receive the same email and can see each other in the To header.

Option 1: Send via template

slug

string

Canonical transactional template slug (use this OR direct content).

templateId

string

Compatibility alias for slug. Despite the field name, pass the saved transactional email’s API slug, not its database ID.

Option 2: Send direct content

subject

string

Email subject (required if no slug)

body

string

Canonical email HTML body (required if no template slug).

html

string

Compatibility alias for body, accepted with subject for direct sends.

preview

string

Preview text

slug/body remain canonical. If you provide both slug and templateId, or both body and html, the paired values must match. A differing pair is rejected with 400 instead of silently choosing one.

Common fields

variables

object

Template variables for personalization. Values can be scalars, nested objects, or arrays. Repeat blocks read arrays from paths such as items. Raw HTML templates can also use subscriber/custom-attribute conditionals like {{#if subscriber.plan}}...{{else}}...{{/if}} and {{#unless subscriber.plan}}...{{/unless}}. If Sequenzy detects likely variable issues before queueing, the successful response includes diagnostics warnings. Missing required values do not block queueing; the worker renders values without defaults as empty strings and continues sending.

subscriberExternalId

string

Customer-owned subscriber ID for single-recipient sends. If it matches an existing subscriber, analytics, localization, and engagement attach to that subscriber even if the delivery email changed. Sequenzy also stores this value on the send, so outbound email webhooks include it as external_id even when no subscriber record exists. Maximum length: 255 characters.

from

string

Custom from address. Format: "Name <email>" or just "email". The domain must be verified for your account. If not verified, this field is silently ignored and the default sender profile is used.

replyTo

string

Reply-to address. Format: "Name <email>" or just "email". Can be any valid email address.When reply tracking is disabled, this is sent as the email’s Reply-To header. When reply tracking is enabled, Sequenzy sends a unique trackable Reply-To address instead and stores this value as the forwarding destination for replies.

With reply tracking and reply forwarding enabled, direct-content sends that omit replyTo forward replies to the company’s default reply profile. If no default reply profile is set, Sequenzy uses the first reply profile in the company as a fallback. If no reply profile exists, replies are still captured in Sequenzy but are not forwarded externally. Template sends use the template’s reply profile unless the API request provides replyTo.

attachments

array

File attachments to include with the email. Maximum total size: 40MB.Each attachment object has:

filename (required): The name of the file as it will appear to the recipient
content: Base64-encoded file content (use this OR path)
path: URL to fetch the file from (use this OR content)

You must provide either content or path, but not both.

Example: Send via template

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@sequenzy.com",
    "subscriberExternalId": "user_123",
    "slug": "welcome",
    "variables": {
      "NAME": "John",
      "LOGIN_URL": "https://sequenzy.com/sign-in"
    }
  }'

Example: Send array data to a repeat block

If a template contains a repeat block with source items and item alias item, child blocks can use merge tags like {{item.title}} and {{item.description}}.

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "slug": "order-confirmation",
    "variables": {
      "NAME": "John",
      "items": [
        {
          "title": "Pro plan",
          "description": "Monthly subscription"
        },
        {
          "title": "Priority support",
          "description": "Added to your account"
        }
      ]
    }
  }'

Example: Send to multiple recipients

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["user1@example.com", "user2@example.com"],
    "slug": "invoice",
    "variables": {
      "INVOICE_NUMBER": "INV-2024-001",
      "AMOUNT": "$500.00"
    }
  }'

Example: Send direct content

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@sequenzy.com",
    "subject": "Your order is confirmed",
    "body": "<h1>Thank you, {{NAME}}!</h1><p>Order #{{ORDER_ID}} confirmed.</p>",
    "variables": {
      "NAME": "John",
      "ORDER_ID": "12345"
    }
  }'

The same direct send can use the html compatibility alias:

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@sequenzy.com",
    "subject": "Connection test",
    "html": "<p>Connected.</p>"
  }'

Example: Send with custom from and reply-to

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "slug": "order-confirmation",
    "variables": {
      "NAME": "John",
      "ORDER_ID": "12345"
    },
    "from": "Notifications <notifications@example.com>",
    "replyTo": "Support <support@example.com>"
  }'

Example: Send with URL-based attachment

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "slug": "invoice",
    "variables": {
      "INVOICE_NUMBER": "INV-2024-001"
    },
    "attachments": [
      {
        "filename": "invoice.pdf",
        "path": "https://example.com/invoices/INV-2024-001.pdf"
      }
    ]
  }'

Example: Send with Base64 attachment

curl -X POST "https://api.sequenzy.com/api/v1/transactional/send" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "subject": "Your report is ready",
    "body": "<p>Please find your report attached.</p>",
    "attachments": [
      {
        "filename": "report.csv",
        "content": "TmFtZSxFbWFpbCxTdGF0dXMKSm9obixqb2huQGV4YW1wbGUuY29tLEFjdGl2ZQ=="
      }
    ]
  }'

Responses

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "welcome",
    "name": "Welcome Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "password-reset",
    "name": "Password Reset"
  },
  "diagnostics": {
    "status": "warning",
    "message": "Email was queued. A required variable is missing and will render as an empty string.",
    "missingRequiredVariables": [
      {
        "name": "RESET_URL",
        "lookupName": "reset_url",
        "message": "Email was queued. Required variable \"RESET_URL\" is missing and will render as an empty string.",
        "usedIn": [
          {
            "surface": "block",
            "blockId": "reset-button",
            "blockType": "button",
            "field": "url"
          }
        ],
        "suggestions": ["resetpasswordlink"]
      }
    ],
    "unusedVariables": [
      {
        "name": "resetpasswordlink",
        "message": "Variable \"resetpasswordlink\" was provided but is not used by the email template.",
        "suggestions": ["reset_url"]
      }
    ]
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": ["user1@example.com", "user2@example.com"],
  "transactional": {
    "id": "txn_abc123",
    "slug": "invoice",
    "name": "Invoice Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com"
}

A successful response means Sequenzy accepted the send for background
processing. Rendering or provider failures after acceptance are recorded on the
email send as failed delivery attempts. Check
GET /api/v1/email-sends/{emailSendId} for status and errorMessage. The
legacy jobId response field remains for compatibility but is not the public
delivery-status contract. If diagnostics.status is warning,
the send is still queued. The warnings identify missing values that will render
as empty strings or variables that look unused.

{
  "success": false,
  "error": "Either 'slug'/'templateId' OR both 'subject' and 'body'/'html' are required"
}

{
  "success": false,
  "error": "Transactional email \"welcome\" is disabled"
}

{
  "success": false,
  "error": "No sender profile configured. Please create a sender profile first."
}

{
  "success": false,
  "error": "Invalid attachments: Attachment[0]: Attachment must have either 'content' (Base64) or 'path' (URL)"
}

{
  "success": false,
  "error": "Attachment \"large-file.pdf\" exceeds maximum size of 40MB"
}

{
  "success": false,
  "error": "Total attachment size exceeds 40MB limit"
}

{
  "success": false,
  "error": "Transactional email with slug \"welcome\" not found"
}

{
  "success": false,
  "error": "Unauthorized"
}

{
  "success": false,
  "error": "Internal server error"
}

Emails are queued for background processing. Track the returned emailSendId with GET /api/v1/email-sends/{emailSendId}. For single-recipient sends without cc or bcc, EMAIL resolves from the recipient address. Pass name, firstName, lastName, FIRST_NAME, or LAST_NAME in variables when a REST API template needs recipient names.

When using multiple to recipients, all recipient addresses are visible to each other. Use single-recipient sends when recipients should not see each other.

Multi-recipient sends produce a single email send record. The full recipient list (to/cc/bcc) is stored on the record and returned as additionalRecipients from the email-sends API. Opens and clicks are tracked for the message as a whole, not per recipient.

Create Transactional EmailCreate a saved transactional email template

Send Transactional Email

curl --request POST \
  --url https://api.sequenzy.com/api/v1/transactional/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "to": [
    "<string>"
  ],
  "slug": "<string>",
  "templateId": "<string>",
  "subject": "<string>",
  "body": "<string>",
  "html": "<string>",
  "preview": "<string>",
  "variables": {},
  "subscriberExternalId": "<string>",
  "from": "<string>",
  "replyTo": "<string>",
  "attachments": [
    {}
  ]
}
'

import requests

url = "https://api.sequenzy.com/api/v1/transactional/send"

payload = {
    "to": ["<string>"],
    "slug": "<string>",
    "templateId": "<string>",
    "subject": "<string>",
    "body": "<string>",
    "html": "<string>",
    "preview": "<string>",
    "variables": {},
    "subscriberExternalId": "<string>",
    "from": "<string>",
    "replyTo": "<string>",
    "attachments": [{}]
}
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({
    to: ['<string>'],
    slug: '<string>',
    templateId: '<string>',
    subject: '<string>',
    body: JSON.stringify('<string>'),
    html: '<string>',
    preview: '<string>',
    variables: {},
    subscriberExternalId: '<string>',
    from: '<string>',
    replyTo: '<string>',
    attachments: [{}]
  })
};

fetch('https://api.sequenzy.com/api/v1/transactional/send', 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://api.sequenzy.com/api/v1/transactional/send",
  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([
    'to' => [
        '<string>'
    ],
    'slug' => '<string>',
    'templateId' => '<string>',
    'subject' => '<string>',
    'body' => '<string>',
    'html' => '<string>',
    'preview' => '<string>',
    'variables' => [
        
    ],
    'subscriberExternalId' => '<string>',
    'from' => '<string>',
    'replyTo' => '<string>',
    'attachments' => [
        [
                
        ]
    ]
  ]),
  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://api.sequenzy.com/api/v1/transactional/send"

	payload := strings.NewReader("{\n  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\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://api.sequenzy.com/api/v1/transactional/send")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.sequenzy.com/api/v1/transactional/send")

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  \"to\": [\n    \"<string>\"\n  ],\n  \"slug\": \"<string>\",\n  \"templateId\": \"<string>\",\n  \"subject\": \"<string>\",\n  \"body\": \"<string>\",\n  \"html\": \"<string>\",\n  \"preview\": \"<string>\",\n  \"variables\": {},\n  \"subscriberExternalId\": \"<string>\",\n  \"from\": \"<string>\",\n  \"replyTo\": \"<string>\",\n  \"attachments\": [\n    {}\n  ]\n}"

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

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "welcome",
    "name": "Welcome Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com",
  "transactional": {
    "id": "txn_abc123",
    "slug": "password-reset",
    "name": "Password Reset"
  },
  "diagnostics": {
    "status": "warning",
    "message": "Email was queued. A required variable is missing and will render as an empty string.",
    "missingRequiredVariables": [
      {
        "name": "RESET_URL",
        "lookupName": "reset_url",
        "message": "Email was queued. Required variable \"RESET_URL\" is missing and will render as an empty string.",
        "usedIn": [
          {
            "surface": "block",
            "blockId": "reset-button",
            "blockType": "button",
            "field": "url"
          }
        ],
        "suggestions": ["resetpasswordlink"]
      }
    ],
    "unusedVariables": [
      {
        "name": "resetpasswordlink",
        "message": "Variable \"resetpasswordlink\" was provided but is not used by the email template.",
        "suggestions": ["reset_url"]
      }
    ]
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": ["user1@example.com", "user2@example.com"],
  "transactional": {
    "id": "txn_abc123",
    "slug": "invoice",
    "name": "Invoice Email"
  }
}

{
  "success": true,
  "emailSendId": "send_abc123",
  "jobId": "job_xyz789",
  "to": "user@sequenzy.com"
}

{
  "success": false,
  "error": "Either 'slug'/'templateId' OR both 'subject' and 'body'/'html' are required"
}

{
  "success": false,
  "error": "Transactional email \"welcome\" is disabled"
}

{
  "success": false,
  "error": "No sender profile configured. Please create a sender profile first."
}

{
  "success": false,
  "error": "Invalid attachments: Attachment[0]: Attachment must have either 'content' (Base64) or 'path' (URL)"
}

{
  "success": false,
  "error": "Attachment \"large-file.pdf\" exceeds maximum size of 40MB"
}

{
  "success": false,
  "error": "Total attachment size exceeds 40MB limit"
}

{
  "success": false,
  "error": "Transactional email with slug \"welcome\" not found"
}

{
  "success": false,
  "error": "Unauthorized"
}

{
  "success": false,
  "error": "Internal server error"
}

​Request Body

​Recipients

​Option 1: Send via template

​Option 2: Send direct content

​Common fields

​Example: Send via template

​Example: Send array data to a repeat block

​Example: Send to multiple recipients

​Example: Send direct content

​Example: Send with custom from and reply-to

​Example: Send with URL-based attachment

​Example: Send with Base64 attachment

​Responses

Request Body

Recipients

Option 1: Send via template

Option 2: Send direct content

Common fields

Example: Send via template

Example: Send array data to a repeat block

Example: Send to multiple recipients

Example: Send direct content

Example: Send with custom from and reply-to

Example: Send with URL-based attachment

Example: Send with Base64 attachment

Responses