# NuPay for Business - Authentication API

**Canonical:** https://apis.io/apis/nubank/nupay-auth/  
**Provider:** Nu (Nubank) — https://apis.io/providers/nubank/  
**Base URL:** https://authentication.spinpay.com.br  
**Documentation:** https://docs.nupaybusiness.com.br/

NuPay for Business - Authentication API is one of 5 APIs that [Nu (Nubank)](https://apis.io/providers/nubank/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Authentication and CIBA. The published artifact set on APIs.io includes API documentation.

OAuth2 app-based authorization, CIBA (Client-Initiated Backchannel Authentication) for web flows, OTP validation, and token issuance / refresh for NuPay merchant integrations.

## Machine-readable artifacts (1)

- **Documentation** — https://docs.nupaybusiness.com.br/

## Other Nu (Nubank) APIs (4)

- [Nubank Open Finance Brasil API](https://apis.io/apis/nubank/open-finance/)
- [NuPay for Business - Checkout API](https://apis.io/apis/nubank/nupay-checkout/)
- [NuPay for Business - Beneficiary Management API](https://apis.io/apis/nubank/nupay-beneficiaries/)
- [NuPay for Business - Event Webhooks](https://apis.io/apis/nubank/nupay-webhook/)

## Tags

Authentication, CIBA

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/nubank/nupay-auth/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/nubank/.