> For the complete documentation index, see [llms.txt](https://synconics.gitbook.io/rest-api/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://synconics.gitbook.io/rest-api/connection/logging-in.md).

# Logging In

Odoo requires users of the REST API to be authenticated before they can query most data

The <mark style="color:orange;">`restapi/1.0/common`</mark> endpoint provides meta-calls that don’t require authentication, such as the authentication itself or fetching version information. To verify if the connection information is correct before trying to authenticate, the simplest call is to ask for the server’s version through the <mark style="color:orange;">`restapi/1.0/common/version`</mark> endpoint. The authentication itself is done through the **OAuth 1.0** <mark style="color:orange;">`restapi/1.0/common/oauth1`</mark> or **OAuth 2.0** <mark style="color:orange;">`restapi/1.0/common/oauth2`</mark> or <mark style="color:orange;">`restapi/1.0/common/basic`</mark> endpoints.

### How you can do

* [Odoo Version Information](/rest-api/connection/logging-in/how-you-can-do/odoo-version-information.md)
* [OAuth1 Authentication](/rest-api/connection/logging-in/how-you-can-do/oauth1-authentication.md)
  * 1\. [Temporary Credential Request](/rest-api/connection/logging-in/how-you-can-do/oauth1-authentication.md#temporary-credential-request)
  * 2\. [Resource Owner Authorization](https://synconics.gitbook.io/rest-api/connection/pages/efCQfpKsK8WwsZamtfLR#2.-resource-owner-authorization)
  * 3\. [Token Credentials Request](https://synconics.gitbook.io/rest-api/connection/pages/efCQfpKsK8WwsZamtfLR#3.-token-credentials-request)
* [OAuth2 Authentication](/rest-api/connection/logging-in/how-you-can-do/oauth2-authentication.md)
  * 1\. [Resource Owner Authorization](https://synconics.gitbook.io/rest-api/connection/pages/9Cz2WmZvkatmQIf3LRlu#1.-resource-owner-authorization)
  * 2\. [Token Credentials Request](https://synconics.gitbook.io/rest-api/connection/pages/9Cz2WmZvkatmQIf3LRlu#2.-token-credentials-request)
* [Basic Authentication](/rest-api/connection/logging-in/how-you-can-do/basic-authentication.md)