curl "https://invoice.horizonpay.co/api/v1/customers?query=acme" \
  -H "Authorization: Bearer $INVOICE_AI_API_KEY"

import InvoiceAI from '@horizonpay/invoice-ai'

const invoiceai = new InvoiceAI() // reads INVOICE_AI_API_KEY

for await (const customer of invoiceai.customers.list({ query: 'acme' })) {
  console.log(customer.id, customer.name)
}

from invoice_ai import InvoiceAI

client = InvoiceAI()  # reads INVOICE_AI_API_KEY

for customer in client.customers.list(query="acme"):
    print(customer.id, customer.name)

{
  "data": [
    {
      "id": "cus_Nf3kQ8pR2mX7vB1cT9wL4sZ6",
      "object": "customer",
      "name": "Acme Industries",
      "email": "[email protected]",
      "phone": null,
      "tax_id": "US-EIN 12-3456789",
      "address": {
        "line1": "4th Floor, Market Tower",
        "line2": null,
        "city": "Austin",
        "state": "TX",
        "postal_code": "73301",
        "country": "US"
      },
      "deleted": false,
      "created": "2026-09-22T09:30:00.000Z"
    }
  ],
  "next_cursor": null
}

{
  "type": "https://invoice.horizonpay.co/problems/unauthorized",
  "title": "Unauthorized",
  "status": 401,
  "detail": "Send your API key as `Authorization: Bearer inv_live_…`.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "unauthorized"
}

{
  "type": "https://invoice.horizonpay.co/problems/forbidden",
  "title": "Insufficient scope",
  "status": 403,
  "detail": "This credential is missing the invoices:write scope.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "forbidden"
}

{
  "type": "https://invoice.horizonpay.co/problems/validation",
  "title": "Validation failed",
  "status": 422,
  "detail": "The cursor is not valid.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "validation",
  "errors": [
    {
      "path": "cursor",
      "message": "Pass the `next_cursor` from the previous page, unchanged."
    }
  ]
}

{
  "type": "https://invoice.horizonpay.co/problems/rate-limited",
  "title": "Too many requests",
  "status": 429,
  "detail": "Rate limit of 120 per 60s exceeded.",
  "instance": "req_7f3c9a1e2b4d4e8a9c6f2d1b0a3e5f71",
  "code": "rate_limited"
}