---
title: API authentication
description: Authentication configurations for API.
locale: en-US
canonical_url: https://www.servicenow.com/docs/r/platform-security/authentication/api-authentication.html
release: brazil
product: Authentication
classification: authentication
topic_type: concept
last_updated: "2026-09-10"
reading_time_minutes: 1
breadcrumb: [Authentication, Access Management]
---

# API authentication

Authentication configurations for API.

API based authentication in ServiceNow validates the identity of a user who accesses an instance, and then authorizes the user to features that match the user's role or job function while making an API call to the ServiceNow instance.

Following are the types of API authentication in ServiceNow:

-   [Certificate based authentication](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-security/authentication/certificate-api-auth.md)
-   [OAuth](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-security/authentication/oauth-inbound-and-outbound.md)
-   [Token-based authentication](https://raw.githubusercontent.com/ServiceNow/ServiceNowDocs/brazil/markdown/platform-security/authentication/token-based-auth-api.md)