latestOpenAPI 3.1.02026-07-265817860.8 KB
29536933c0dc
billing
Previews the billing changes that would occur when attaching multiple plans, without actually making any changes.
Use this endpoint to show customers what they will be charged before confirming a multi-plan subscription.
post/v1/billing.preview_multi_attach
Headers
x-api-versionstring required
Request body
Example request
{
"customer_id": "cus_123",
"plans": [
{
"plan_id": "pro_plan"
},
{
"plan_id": "addon_seats",
"feature_quantities": [
{
"feature_id": "seats",
"quantity": 5
}
]
}
]
}Response
OK
Example response
{
"customerId": "charles",
"lineItems": [
{
"display_name": "Pro seed",
"description": "Pro seed - Base Price (from 18 Feb 2026 to 18 Mar 2026)",
"subtotal": 20,
"total": 20,
"discounts": []
}
],
"subtotal": 20,
"total": 20,
"currency": "usd"
}