Attach Plan

POST /v1/attach

Attach Plan

cURL

curl --request POST \
  --url https://api.example.com/v1/attach \
  --header 'Content-Type: application/json' \
  --data '
{
  "customer_id": "<string>",
  "product_id": "<string>",
  "entity_id": "<string>",
  "invoice": true,
  "enable_product_immediately": true,
  "finalize_invoice": true,
  "redirect_mode": "<string>",
  "success_url": "<string>",
  "new_billing_subscription": true,
  "plan_schedule": {
    "start_at": 123
  },
  "discounts": [
    {
      "coupon": "<string>",
      "promotion_code": "<string>"
    }
  ],
  "billing_behavior": "<string>",
  "options": [
    {
      "feature_id": "<string>",
      "quantity": 123
    }
  ],
  "free_trial": {
    "duration_length": 123,
    "duration_type": "<string>"
  },
  "transition_rules": {},
  "subscription_id": "<string>",
  "custom_line_items": [
    {}
  ]
}
'

import requests

url = "https://api.example.com/v1/attach"

payload = {
    "customer_id": "<string>",
    "product_id": "<string>",
    "entity_id": "<string>",
    "invoice": True,
    "enable_product_immediately": True,
    "finalize_invoice": True,
    "redirect_mode": "<string>",
    "success_url": "<string>",
    "new_billing_subscription": True,
    "plan_schedule": { "start_at": 123 },
    "discounts": [
        {
            "coupon": "<string>",
            "promotion_code": "<string>"
        }
    ],
    "billing_behavior": "<string>",
    "options": [
        {
            "feature_id": "<string>",
            "quantity": 123
        }
    ],
    "free_trial": {
        "duration_length": 123,
        "duration_type": "<string>"
    },
    "transition_rules": {},
    "subscription_id": "<string>",
    "custom_line_items": [{}]
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    customer_id: '<string>',
    product_id: '<string>',
    entity_id: '<string>',
    invoice: true,
    enable_product_immediately: true,
    finalize_invoice: true,
    redirect_mode: '<string>',
    success_url: '<string>',
    new_billing_subscription: true,
    plan_schedule: {start_at: 123},
    discounts: [{coupon: '<string>', promotion_code: '<string>'}],
    billing_behavior: '<string>',
    options: [{feature_id: '<string>', quantity: 123}],
    free_trial: {duration_length: 123, duration_type: '<string>'},
    transition_rules: {},
    subscription_id: '<string>',
    custom_line_items: [{}]
  })
};

fetch('https://api.example.com/v1/attach', 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.example.com/v1/attach",
  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([
    'customer_id' => '<string>',
    'product_id' => '<string>',
    'entity_id' => '<string>',
    'invoice' => true,
    'enable_product_immediately' => true,
    'finalize_invoice' => true,
    'redirect_mode' => '<string>',
    'success_url' => '<string>',
    'new_billing_subscription' => true,
    'plan_schedule' => [
        'start_at' => 123
    ],
    'discounts' => [
        [
                'coupon' => '<string>',
                'promotion_code' => '<string>'
        ]
    ],
    'billing_behavior' => '<string>',
    'options' => [
        [
                'feature_id' => '<string>',
                'quantity' => 123
        ]
    ],
    'free_trial' => [
        'duration_length' => 123,
        'duration_type' => '<string>'
    ],
    'transition_rules' => [
        
    ],
    'subscription_id' => '<string>',
    'custom_line_items' => [
        [
                
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "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.example.com/v1/attach"

	payload := strings.NewReader("{\n  \"customer_id\": \"<string>\",\n  \"product_id\": \"<string>\",\n  \"entity_id\": \"<string>\",\n  \"invoice\": true,\n  \"enable_product_immediately\": true,\n  \"finalize_invoice\": true,\n  \"redirect_mode\": \"<string>\",\n  \"success_url\": \"<string>\",\n  \"new_billing_subscription\": true,\n  \"plan_schedule\": {\n    \"start_at\": 123\n  },\n  \"discounts\": [\n    {\n      \"coupon\": \"<string>\",\n      \"promotion_code\": \"<string>\"\n    }\n  ],\n  \"billing_behavior\": \"<string>\",\n  \"options\": [\n    {\n      \"feature_id\": \"<string>\",\n      \"quantity\": 123\n    }\n  ],\n  \"free_trial\": {\n    \"duration_length\": 123,\n    \"duration_type\": \"<string>\"\n  },\n  \"transition_rules\": {},\n  \"subscription_id\": \"<string>\",\n  \"custom_line_items\": [\n    {}\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	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.example.com/v1/attach")
  .header("Content-Type", "application/json")
  .body("{\n  \"customer_id\": \"<string>\",\n  \"product_id\": \"<string>\",\n  \"entity_id\": \"<string>\",\n  \"invoice\": true,\n  \"enable_product_immediately\": true,\n  \"finalize_invoice\": true,\n  \"redirect_mode\": \"<string>\",\n  \"success_url\": \"<string>\",\n  \"new_billing_subscription\": true,\n  \"plan_schedule\": {\n    \"start_at\": 123\n  },\n  \"discounts\": [\n    {\n      \"coupon\": \"<string>\",\n      \"promotion_code\": \"<string>\"\n    }\n  ],\n  \"billing_behavior\": \"<string>\",\n  \"options\": [\n    {\n      \"feature_id\": \"<string>\",\n      \"quantity\": 123\n    }\n  ],\n  \"free_trial\": {\n    \"duration_length\": 123,\n    \"duration_type\": \"<string>\"\n  },\n  \"transition_rules\": {},\n  \"subscription_id\": \"<string>\",\n  \"custom_line_items\": [\n    {}\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.example.com/v1/attach")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"customer_id\": \"<string>\",\n  \"product_id\": \"<string>\",\n  \"entity_id\": \"<string>\",\n  \"invoice\": true,\n  \"enable_product_immediately\": true,\n  \"finalize_invoice\": true,\n  \"redirect_mode\": \"<string>\",\n  \"success_url\": \"<string>\",\n  \"new_billing_subscription\": true,\n  \"plan_schedule\": {\n    \"start_at\": 123\n  },\n  \"discounts\": [\n    {\n      \"coupon\": \"<string>\",\n      \"promotion_code\": \"<string>\"\n    }\n  ],\n  \"billing_behavior\": \"<string>\",\n  \"options\": [\n    {\n      \"feature_id\": \"<string>\",\n      \"quantity\": 123\n    }\n  ],\n  \"free_trial\": {\n    \"duration_length\": 123,\n    \"duration_type\": \"<string>\"\n  },\n  \"transition_rules\": {},\n  \"subscription_id\": \"<string>\",\n  \"custom_line_items\": [\n    {}\n  ]\n}"

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

200

{
  "customer_id": "<string>",
  "entity_id": "<string>",
  "invoice": {
    "status": "<string>",
    "stripe_id": "<string>",
    "total": 123,
    "currency": "<string>",
    "hosted_invoice_url": "<string>"
  },
  "payment_url": "<string>",
  "required_action": {
    "code": "<string>",
    "reason": "<string>"
  },
  "error": {
    "message": "<string>",
    "code": "<string>"
  }
}

Attaches a plan to a customer. Handles new subscriptions, upgrades, downgrades, and add-on products.

Authentication

Requires a valid API secret key in the Authorization header:

Authorization: Bearer YOUR_SECRET_KEY

Request Body

customer_id · string · required

The ID of the customer.

product_id · string · required

The ID of the plan/product to attach to the customer.

entity_id · string

The ID of the entity, if attaching the plan to a specific entity.

invoice · boolean

If true, creates an invoice for the subscription. Use this for deferred payment flows.

enable_product_immediately · boolean

If true, enables the product immediately even if an invoice is pending payment.

finalize_invoice · boolean

If true, finalizes the invoice immediately. Only applicable when invoice is true.

redirect_mode · string · default: "always"

Controls when to redirect the customer to a checkout page. Options:

• always: Always redirect to checkout
• if_required: Only redirect if payment action is required
• never: Never redirect, handle payment programmatically

success_url · string

URL to redirect the customer to after successful payment. Used with redirect_mode.

new_billing_subscription · boolean

If true, creates a new billing subscription even if the customer has an existing one.

plan_schedule · object

Schedule when the plan should become active.

start_at · number

Timestamp (in milliseconds) when the plan should start.

discounts · array

Array of discount objects to apply to the subscription.

coupon · string

Stripe coupon ID to apply.

promotion_code · string

Stripe promotion code to apply.

billing_behavior · string

Controls billing behavior for plan transitions:

• prorate_immediately (default): Invoice line items are charged immediately
• next_cycle_only: Do not create any charges due to the attach

options · array

Array of feature quantity overrides.

feature_id · string

The feature ID to configure.

quantity · number

The quantity for this feature.

free_trial · object

Free trial configuration for the subscription.

duration_length · number

Length of the trial period.

duration_type · string

Unit of the trial period: day, week, or month.

transition_rules · object

Rules for how to transition between plans.

subscription_id · string

Specific subscription ID to attach the plan to.

custom_line_items · array

Array of custom line items to add to the invoice.

Response

customer_id · string

The ID of the customer.

entity_id · string

The ID of the entity, if the plan was attached to an entity.

invoice · object

Invoice details if an invoice was created. Only present when a charge was made.

status · string

The status of the invoice (e.g., ‘paid’, ‘open’, ‘draft’).

stripe_id · string

The Stripe invoice ID.

total · number

The total amount of the invoice in cents.

currency · string

The three-letter ISO currency code (e.g., ‘usd’).

hosted_invoice_url · string

URL to the hosted invoice page where the customer can view and pay the invoice.

payment_url · string

URL to redirect the customer to complete payment. Null if no payment action is required.

required_action · object

Details about any action required to complete the payment. Present when the payment could not be processed automatically.

code · string

The type of action required to complete the payment. One of:

• 3ds_required: 3D Secure authentication is needed
• payment_method_required: Customer needs to add a payment method
• payment_failed: Payment was declined

reason · string

A human-readable explanation of why this action is required.

Example Request

curl -X POST https://api.autumnai.com/v1/attach \
  -H "Authorization: Bearer YOUR_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "customer_id": "cus_123",
    "product_id": "pro_plan"
  }'

Example Response

{
  "customer_id": "cus_123",
  "entity_id": null,
  "invoice": {
    "status": "paid",
    "stripe_id": "in_1234567890",
    "total": 4900,
    "currency": "usd",
    "hosted_invoice_url": "https://invoice.stripe.com/i/acct_xxx/test_xxx"
  },
  "payment_url": null,
  "required_action": null
}

Error Responses

error · object

message · string

Human-readable error message.

code · string

Machine-readable error code. Common codes:

• customer_not_found: The specified customer doesn’t exist
• product_not_found: The specified product doesn’t exist
• invalid_inputs: Request validation failed
• stripe_error: Payment provider error occurred
• customer_has_no_payment_method: Customer needs to add a payment method

Example Error Response

{
  "error": {
    "message": "Customer not found",
    "code": "customer_not_found"
  }
}