Invoices

Invoices let you send professional billing documents to customers. Each invoice includes a payment link, optional line items, and due date tracking. When the customer pays, the invoice status updates automatically.

Create an Invoice

POST /api/v1/invoices

customer_email

string

required

Email address of the invoice recipient.

customer_name

string

Customer name displayed on the invoice.

amount

number

required

Total invoice amount.

token

string

default:"USDC"

Token to accept: USDC, USDT, SOL.

description

string

required

Invoice description or memo.

line_items

array

Itemized breakdown of the invoice.Each item has:

description (string, required): Item description
quantity (number, required): Quantity
unit_price (number, required): Price per unit

due_date

string

ISO 8601 date when payment is due.

metadata

object

Arbitrary key-value pairs.

onramp

boolean

default:"false"

When true, the payment link generated by Send Invoice will use the PAJ onramp flow (NGN bank transfer → USDC settlement) instead of a direct crypto payment. Ideal for customers who prefer to pay from a Nigerian bank account.

amount_ngn

number

Original NGN amount for exact PAJ conversion. Bypasses a live FX re-quote at checkout time. Only relevant when onramp is true.

payer_service_charge

boolean

default:"false"

When true (and onramp is true), a transparent service charge — max(₦30, ceil(amount_ngn × 2.5%)) — is added on top and billed to the payer rather than absorbed by the merchant.

payment_link_max_uses

integer

default:"1"

Maximum number of times the generated payment link can be used. Defaults to 1 on send because invoices are targeted at a single customer. Set to a higher value (or omit for unlimited) only if you intentionally want the link reusable.

collect_customer_info

boolean

default:"false"

When true, the checkout page shows an expanded customer-details form (name, phone, company, billing address) before the payment step.

Examples

curl -X POST https://api.zendfi.tech/api/v1/invoices \
  -H "Authorization: Bearer zfi_test_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "customer_email": "client@company.com",
    "customer_name": "Acme Corp",
    "amount": 2500.00,
    "description": "Web Development - March 2026",
    "line_items": [
      {"description": "Frontend Development", "quantity": 40, "unit_price": 50},
      {"description": "Backend API Work", "quantity": 10, "unit_price": 50}
    ],
    "due_date": "2026-03-15T00:00:00Z"
  }'

Response

{
  "id": "inv_test_abc123",
  "invoice_number": "INV-2026-0042",
  "customer_email": "client@company.com",
  "customer_name": "Acme Corp",
  "amount_usd": 2500.00,
  "currency": "USD",
  "token": "USDC",
  "description": "Web Development - March 2026",
  "line_items": [
    {"description": "Frontend Development", "quantity": 40, "unit_price": 50},
    {"description": "Backend API Work", "quantity": 10, "unit_price": 50}
  ],
  "status": "draft",
  "payment_url": null,
  "due_date": "2026-03-15T00:00:00Z",
  "sent_at": null,
  "paid_at": null,
  "created_at": "2026-03-01T12:00:00Z",
  "onramp": false,
  "payment_link_max_uses": null,
  "collect_customer_info": false,
  "payer_service_charge": false,
  "amount_ngn": null
}

List Invoices

GET /api/v1/invoices

Returns all invoices for the authenticated merchant.

const invoices = await zendfi.listInvoices();

Get an Invoice

GET /api/v1/invoices/{id}

string

required

Invoice ID (e.g., inv_test_abc123).

const invoice = await zendfi.getInvoice('inv_test_abc123');

Send an Invoice

POST /api/v1/invoices/{id}/send

Sends the invoice to the customer via email with a payment link. The invoice status changes from draft to sent. When send is called a payment link is created automatically using the invoice’s settings:

If onramp is true on the invoice, the payment link will use the PAJ onramp flow (NGN bank transfer).
max_uses on the generated link defaults to 1 (the invoice’s payment_link_max_uses value, or 1 if not set).
mode (test vs live) is inherited from the API key or, for dashboard calls, from the ?mode query parameter (default: live).

mode

string

default:"live"

Dashboard route only (/api/v1/merchants/me/invoices/:id/send). Pass ?mode=test to generate a devnet payment link instead of a mainnet one.

Example

curl -X POST https://api.zendfi.tech/api/v1/invoices/inv_test_abc123/send \
  -H "Authorization: Bearer zfi_test_your_key"

Response

{
  "success": true,
  "invoice_id": "inv_test_abc123",
  "invoice_number": "INV-2026-0042",
  "sent_to": "client@company.com",
  "payment_url": "https://checkout.zendfi.tech/checkout/abc123xyz",
  "status": "sent",
  "onramp": false,
  "max_uses": 1
}

Dashboard Routes

The following routes are available when authenticated via a merchant session (dashboard cookie auth) rather than an API key. They are identical to the API-key routes but scoped under /api/v1/merchants/me/invoices.

Method	Path	Description
`POST`	`/api/v1/merchants/me/invoices`	Create invoice
`GET`	`/api/v1/merchants/me/invoices`	List invoices
`GET`	`/api/v1/merchants/me/invoices/:id`	Get invoice
`POST`	`/api/v1/merchants/me/invoices/:id/send`	Send invoice (`?mode=live\|test`)

Invoice Status Lifecycle

Status	Description
`draft`	Invoice created but not yet sent
`sent`	Invoice emailed to customer; payment link is active
`paid`	Customer payment confirmed on-chain
`overdue`	Due date passed without payment (auto-updated nightly)
`cancelled`	Invoice manually cancelled

Onramp Invoices — How It Works

When an invoice is created with onramp: true and then sent:

A payment link is created with onramp: true, max_uses: 1 (or your configured value), and the PAJ metadata (amount_ngn, payer_service_charge).
The payment link URL is included in the invoice email.
The customer opens the link and sees the Pay with Bank flow — no crypto wallet needed.
They receive a virtual account number, transfer the NGN amount, and the conversion to USDC is settled to your merchant wallet automatically.

Invoice created (onramp=true)
        │
        ▼
sendInvoice() called
        │
        ├─ Creates payment_link (onramp=true, max_uses=1, mode=live)
        ├─ Emails customer with hosted checkout URL
        └─ Invoice status → "sent"
                │
                ▼
        Customer opens link
                │
                ▼
        PAJ onramp flow (bank transfer → USDC)
                │
                ▼
        Payment confirmed → Invoice status → "paid"

Webhook Events

Event	When
`InvoiceCreated`	Invoice created
`InvoiceSent`	Invoice emailed to customer
`InvoicePaid`	Invoice payment confirmed

API Reference

​Invoices

​Create an Invoice

​Examples

​Response

​List Invoices

​Get an Invoice

​Send an Invoice

​Example

​Response

​Dashboard Routes

​Invoice Status Lifecycle

​Onramp Invoices — How It Works

​Webhook Events

Invoices

Create an Invoice

Examples

Response

List Invoices

Get an Invoice

Send an Invoice

Example

Response

Dashboard Routes

Invoice Status Lifecycle

Onramp Invoices — How It Works

Webhook Events