Deliver

The Deliver endpoint queues an email for delivery through Customer.io. JustAI selects the optimal variant and handles delivery on your behalf.

Note

This endpoint is specific to Customer.io. Messages are queued and processed asynchronously at a rate of 100 messages per second.

Endpoint

POST https://worker.justwords.ai/api/deliver/:org_slug

Authentication

This endpoint requires authentication via an API key. Include your key in the X-Api-Key header.

See the Quickstart for details on creating and managing API keys.

Request

Path Parameters

Parameter	Type	Required	Description
org_slug	string	Yes	Your organization identifier (e.g., your-company-name).

Request Body

Field	Type	Required	Default	Description
template_id	string	Yes	-	Unique identifier for the template.
email	string	Yes	-	Recipient email address.
copy_id	string	No	-	Force a specific variant by ID.
attrs	object	No	{}	Key-value pairs for targeting/filtering.
fields	object	No	{}	Key-value pairs for LiquidJS template variable substitution.
lookback_days	number	No	14	Number of days of historical data to use for optimization.
offset_days	number	No	3	Number of days to offset the lookback window.
use_cache	boolean	No	true	Whether to use cached results.
epsilon	number	No	-	Exploration rate override for the bandit algorithm.

Examples

Basic Request

cURL

curl -X POST https://worker.justwords.ai/api/deliver/your-org \
  -H "X-Api-Key: your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "template_id": "welcome-email",
    "email": "alice@example.com"
  }'

JavaScript

const response = await fetch(
  'https://worker.justwords.ai/api/deliver/your-org',
  {
    method: 'POST',
    headers: {
      'X-Api-Key': 'your_api_key',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      template_id: 'welcome-email',
      email: 'alice@example.com',
    }),
  }
);

const data = await response.json();
console.log(data);

Python

import requests

url = "https://worker.justwords.ai/api/deliver/your-org"
headers = {
    "X-Api-Key": "your_api_key",
    "Content-Type": "application/json"
}
payload = {
    "template_id": "welcome-email",
    "email": "alice@example.com"
}

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

With Personalization

{
  "template_id": "welcome-email",
  "email": "alice@example.com",
  "fields": {
    "user_name": "Alice",
    "account_type": "premium"
  },
  "attrs": {
    "plan": "premium",
    "region": "us-east"
  }
}

Response

Success Response (200 OK)

{
  "status": "ok"
}

A 200 response means the message has been queued for delivery. It does not mean the email has been sent yet — delivery happens asynchronously.