API Reference · Invoices

Send an invoice

Transitions a DRAFT invoice to OPEN and emails it to the customer.

POST/v1/invoices/:id/send

Generates the PDF, attaches it to an email, and delivers via SendGrid. Fires `invoice.sent`. Safe to retry — if the initial send partially failed, calling this again resumes delivery.

Returnsinvoice object

Path parameters

idstringRequired

Invoice id (`inv_…`).

Errors

404

resource_missing

No invoice exists with that id.

409

invoice_not_draft

Invoice is not in DRAFT status.

Request

curl -X POST https://lunipay.io/api/v1/invoices/inv_01JRZK7T9A3BXCZV2QKH5E8RMP/send \
  -H "Authorization: Bearer sk_test_YOUR_KEY"

Response

{
  "id": "inv_01JRZK7T9A3BXCZV2QKH5E8RMP",
  "object": "invoice",
  "livemode": false,
  "customer_id": "cus_01JRZK2Q4T9ZS0VCNA3HX7W9EY",
  "invoice_number": "INV-0042",
  "status": "OPEN",
  "currency": "usd",
  "subtotal_cents": 10000,
  "tax_rate_bps": 1500,
  "tax_amount_cents": 1500,
  "total_cents": 11500,
  "amount_paid_cents": 0,
  "amount_due_cents": 11500,
  "payment_terms": "net_30",
  "due_date": "2026-05-14",
  "notes": "Thanks for your business.",
  "line_items": [
    {
      "description": "Consulting — April 2026",
      "quantity": 10,
      "unit_price_cents": 1000,
      "total_cents": 10000
    }
  ],
  "installment_enabled": false,
  "installment_count": null,
  "hosted_invoice_url": "https://lunipay.io/pay/inv_01JRZK7T9A3BXCZV2QKH5E8RMP",
  "metadata": null,
  "sent_at": 1713100900,
  "paid_at": null,
  "created": 1713100800,
  "updated": 1713100800
}