Sending Emails

Send transactional emails one at a time or in batches, and query your message history.

Send an email

Send a single transactional email.

Request body

Attachment object

Max 10 attachments per message. Each file must not exceed 5 MB; the total across all attachments must not exceed 10 MB.

Response

{
  "messageId": "fd92bd3f-969a-4ff6-87dc-a8b0a16e0297",
  "status": "queued",
  "from": "your-default-sender@yourbrand.com"
}

messageId is a UUID. Use it with Get a message to look up delivery status. from is the address the email was sent from — for bx_preview_ keys this is noreply@brixus365.dev; for bx_live_ keys it’s your default sender.

Example

1curl -X POST https://app.brixus365.com/api/v1/emails \
2-H "X-API-Key: bx_live_your_key_here" \
3-H "Content-Type: application/json" \
4-d '{
5  "to": "customer@example.com",
6  "starterTemplate": "password_reset",
7  "variables": {
8    "reset_url": "https://app.example.com/reset?token=abc123",
9    "expiry_minutes": 30
10  }
11}'

For 8 more languages (PHP, .NET, Java, Go, Rust, Ruby, Elixir, Swift) see Code examples.

Errors

Send a batch

Send up to 100 emails in a single request. Each message is processed independently — a failure on one doesn’t affect the others. Available on free plan and above (preview keys can’t use batch).

Request body

Response

{
  "results": [
    {
      "idx": 0,
      "messageId": "c2bb8f70-9ae9-4e7a-a8d1-d84a222e0849",
      "status": "queued",
      "from": "your-default-sender@yourbrand.com",
      "error": null
    },
    {
      "idx": 1,
      "messageId": null,
      "status": null,
      "from": null,
      "error": {
        "code": "recipient_suppressed",
        "message": "This address has previously bounced.",
        "type": "invalid_request_error"
      }
    }
  ]
}

idx corresponds to the zero-based position in your messages array. Always check error on each result.

Errors

List messages

Returns a paginated list of messages sent via API.

Query parameters

Response

{
  "items": [
    {
      "messageId": "dceaaa96-a806-43d2-ac2d-8396bbd3188a",
      "recipientEmail": "customer@example.com",
      "subject": "Welcome to Acme",
      "status": "sent",
      "createdAt": "2026-05-04T10:45:26+00:00",
      "updatedAt": "2026-05-04T10:45:26+00:00",
      "errorMessage": null
    }
  ],
  "total": 8,
  "skip": 0,
  "limit": 50
}

Get a message

Look up a single message by its ID.

Path parameters

Response

{
  "messageId": "dceaaa96-a806-43d2-ac2d-8396bbd3188a",
  "status": "sent",
  "recipientEmail": "customer@example.com",
  "subject": "Welcome to Acme",
  "fromName": null,
  "providerMessageId": "0109019df17b973a-...-000000",
  "errorMessage": null,
  "createdAt": "2026-05-04T10:45:26+00:00",
  "updatedAt": "2026-05-04T10:45:26+00:00"
}

providerMessageId is the upstream delivery provider’s tracking ID. Useful when investigating delivery issues with our support team.

Errors

Analytics

Aggregate delivery metrics for a time window.

Query parameters

Response

{
  "totalMessages": 8,
  "deliveryRate": 1.0,
  "bounceRate": 0.0,
  "complaintRate": 0.0,
  "windowStart": "2026-05-03T00:00:00+00:00",
  "windowEnd": "2026-05-04T23:59:59+00:00",
  "bucket": "day",
  "volume": [
    {
      "timestamp": "2026-05-04T00:00:00+00:00",
      "count": 8,
      "sent": 8,
      "delivered": 7,
      "bounced": 0,
      "complained": 0,
      "failed": 1
    }
  ],
  "topErrors": []
}