SendCrane API Docs

Send transactional and marketing emails from your app using a simple REST API.

https://sendcrane.com/api/v1

All requests must be authenticated with an API key. Responses are JSON.

Free Trial

When you hit the daily limit, the API returns 429 Too Many Requests with an upgrade_url in the response body.

{
  "success": false,
  "error": "daily_limit_reached",
  "message": "You have reached your daily limit of 5 emails on the free trial.",
  "sent_today": 5,
  "daily_limit": 5,
  "upgrade_url": "https://sendcrane.com/billing"
}

When the trial expires, the API returns 402 Payment Required:

{
  "success": false,
  "error": "subscription_required",
  "message": "Your free trial has expired. Please subscribe to continue sending emails.",
  "upgrade_url": "https://sendcrane.com/billing"
}

Pricing

Quick Start

1. 1Register at sendcrane.com/register — no credit card needed.
2. 2Go to API Keys in your dashboard and click Generate API Key. Copy the key — it's only shown once.
3. 3Go to Templates and create your first email template. Note the template type (e.g. transaction).
4. 4Call the Send Email API with your API key and template type.

curl -X POST https://sendcrane.com/api/v1/email/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "template_type": "transaction",
    "to": "customer@example.com",
    "variables": {
      "user_name": "Jane",
      "order_id": "12345"
    }
  }'

Authentication

All API requests require a valid API key passed as a Bearer token in the Authorization header:

Authorization: Bearer sk_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Send Email

Send an email using a template from your account.

Request Body

* Provide either template_type or template_name (or both).

Example Request

curl -X POST https://sendcrane.com/api/v1/email/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "template_name": "order-confirmation",
    "to": "customer@example.com",
    "variables": {
      "user_name": "John Doe",
      "order_id": "ORD-9821",
      "amount": "UGX 85,000"
    }
  }'

Success Response 200 OK

{
  "success": true,
  "message": "Email sent successfully"
}

List Templates

Retrieve the available email templates for your API key.

Example Request

curl https://sendcrane.com/api/v1/email/templates \
  -H "Authorization: Bearer YOUR_API_KEY"

Response

{
  "templates": [
    {
      "name": "order-confirmation",
      "type": "transaction",
      "subject": "Your order has been confirmed",
      "is_active": true
    },
    {
      "name": "welcome-email",
      "type": "notification",
      "subject": "Welcome to our platform",
      "is_active": true
    }
  ]
}

Template Variables

Templates support dynamic variable substitution using double curly brace syntax. When creating a template, use {{variable_name}} as a placeholder anywhere in the subject or HTML body.

Example Template HTML

<p>Hello {{user_name}},</p>
<p>Your order <strong>{{order_id}}</strong> has been received.</p>
<p>Total: {{amount}}</p>

Then pass those values in the variables field when sending:

"variables": {
  "user_name": "Jane",
  "order_id": "ORD-1234",
  "amount": "UGX 45,000"
}

Custom Domain Setup

Sending from your own domain improves deliverability and brand trust. Trial accounts can add 1 domain. Pro accounts have no limit.

1. 1
   Add your domain — go to Domains in your dashboard and enter your domain (e.g. mail.yourdomain.com).
2. 2
   Add the DNS TXT record — copy the verification token shown and add it as a TXT record on your domain in your DNS provider (Cloudflare, GoDaddy, etc.). The record looks like: v=xxxxxxxx...
3. 3
   Verify — click Verify in the dashboard. DNS changes can take up to 48 hours to propagate.
4. 4
   Use it — set your template's From Email to an address on your verified domain (e.g. noreply@yourdomain.com).

Error Handling

Error Response Shape

{
  "success": false,
  "error": "error_code",
  "message": "Human-readable description of the error"
}

Rate Limits

Limits reset at midnight UTC. Upgrade at any time at sendcrane.com/billing.

Support