Send email

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your monthly wash summary",
    "html": "<h1>Hi!</h1><p>You washed 12 times this month.</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["customer@example.com", "other@example.com"],
    "subject": "Flash sale this weekend",
    "html": "<p>50% off unlimited plans — this weekend only!</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Welcome to Squeaky Clean Car Wash",
    "html": "<p>Thanks for joining!</p>",
    "from": "Squeaky Clean <squeaky@mail.nautilus.co>",
    "replyTo": "support@squeakyclean.com"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your invoice",
    "html": "<p>Please find your invoice attached.</p>",
    "attachments": [
      { "filename": "invoice.pdf", "path": "https://example.com/invoices/123.pdf" }
    ]
  }'

{
  "success": true,
  "results": [
    {
      "to": "customer@example.com",
      "success": true,
      "id": "abc123"
    }
  ]
}

{
  "success": false,
  "results": [
    {
      "to": "customer@example.com",
      "success": true,
      "id": "abc123"
    },
    {
      "to": "invalid@",
      "success": false,
      "error": "Invalid email address"
    }
  ]
}

{
  "error": "Invalid request format",
  "details": [
    {
      "code": "<string>",
      "message": "<string>",
      "path": [
        "<string>"
      ]
    }
  ]
}

{
  "error": "Unauthorized"
}

{
  "error": "Email sending is not configured for this tenant. Contact support."
}

{
  "error": "<string>"
}

POST

api

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your monthly wash summary",
    "html": "<h1>Hi!</h1><p>You washed 12 times this month.</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["customer@example.com", "other@example.com"],
    "subject": "Flash sale this weekend",
    "html": "<p>50% off unlimited plans — this weekend only!</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Welcome to Squeaky Clean Car Wash",
    "html": "<p>Thanks for joining!</p>",
    "from": "Squeaky Clean <squeaky@mail.nautilus.co>",
    "replyTo": "support@squeakyclean.com"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your invoice",
    "html": "<p>Please find your invoice attached.</p>",
    "attachments": [
      { "filename": "invoice.pdf", "path": "https://example.com/invoices/123.pdf" }
    ]
  }'

{
  "success": true,
  "results": [
    {
      "to": "customer@example.com",
      "success": true,
      "id": "abc123"
    }
  ]
}

{
  "success": false,
  "results": [
    {
      "to": "customer@example.com",
      "success": true,
      "id": "abc123"
    },
    {
      "to": "invalid@",
      "success": false,
      "error": "Invalid email address"
    }
  ]
}

{
  "error": "Invalid request format",
  "details": [
    {
      "code": "<string>",
      "message": "<string>",
      "path": [
        "<string>"
      ]
    }
  ]
}

{
  "error": "Unauthorized"
}

{
  "error": "Email sending is not configured for this tenant. Contact support."
}

{
  "error": "<string>"
}

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your monthly wash summary",
    "html": "<h1>Hi!</h1><p>You washed 12 times this month.</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["customer@example.com", "other@example.com"],
    "subject": "Flash sale this weekend",
    "html": "<p>50% off unlimited plans — this weekend only!</p>"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Welcome to Squeaky Clean Car Wash",
    "html": "<p>Thanks for joining!</p>",
    "from": "Squeaky Clean <squeaky@mail.nautilus.co>",
    "replyTo": "support@squeakyclean.com"
  }'

curl -X POST https://app.nautilus.co/api/v1/email \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "customer@example.com",
    "subject": "Your invoice",
    "html": "<p>Please find your invoice attached.</p>",
    "attachments": [
      { "filename": "invoice.pdf", "path": "https://example.com/invoices/123.pdf" }
    ]
  }'

Sender address

The from field is optional. The allowed values depend on the type of API key you use (see Key types). Tenant-scoped keys — the default sender is {Tenant Name} <{slug}@mail.nautilus.co>, where {slug} is your organization’s slug. If you provide from explicitly, the email address must be exactly {slug}@mail.nautilus.co; you may customize the display name:

Squeaky Clean Promos <squeaky-clean@mail.nautilus.co>

Tenants without a configured slug receive a 422 response. Platform keys — the default sender is Nautilus <contact@mail.nautilus.co>. If you provide from explicitly, the address must use the @mail.nautilus.co domain.

Attachments

Add files to an email with the attachments array. Each attachment requires a filename and either:

path — a publicly accessible URL to the file
content — the file as a base64-encoded string

Field	Type	Required	Description
filename	string	Yes	Filename with extension (e.g. `report.pdf`)
path	string	No	Public URL to the file
content	string	No	Base64-encoded file content

Each attachment must include either path or content, but not both.

Multi-send behavior

When sending to multiple recipients, each email is dispatched in parallel. The response includes per-recipient results:

200 — All recipients succeeded
207 — At least one recipient failed (check results for details)

Individual failures do not block other recipients. Successful results include an id field for tracking.

Errors

400 — Validation error, including a from address that doesn’t match the rules for your key type
401 — Missing or invalid Bearer token
422 — Your tenant is not configured for email sending. Contact Nautilus support.
500 — Internal server error

Authorizations

Authorization

string

header

required

Clerk tenant API key. The organizationId encoded by the key is the exact and only tenant scope.

Body

application/json

required

Recipient email address(es). Accepts a single address or an array.

Example:

"customer@example.com"

subject

string

required

The email subject line.

Minimum string length: 1

html

string

required

The email body as HTML.

Minimum string length: 1

from

string

Sender address. Allowed values depend on key type. Tenant-scoped keys: the email address part must be exactly {slug}@mail.nautilus.co where {slug} is the organization's slug; the display name is free-form. Default: {Tenant Name} <{slug}@mail.nautilus.co>. Platform keys: must use the @mail.nautilus.co domain. Default: Nautilus <contact@mail.nautilus.co>.

replyTo

string<email>

Optional reply-to email address.

attachments

object[]

Optional file attachments. Each must include a filename and either a path (public URL) or content (base64-encoded string).

Show child attributes

Response

All emails sent successfully

success

boolean

required

true when every recipient was sent successfully, false otherwise.

results

object[]

required

Per-recipient delivery results.

Show child attributes

API documentation

Sites

Products

Checkout links

Purchases

Contacts

Marketing

Forms

Vouchers

Links

Automations

Surveys

Cases

Cancellations

Sonny's POS

Message

Email

Analytics

Integration

Sender address

Attachments

Multi-send behavior

Errors

Authorizations

Body

Response

​Sender address

​Attachments

​Multi-send behavior

​Errors

Authorizations

Body

Response

Sender address

Attachments

Multi-send behavior

Errors