> For the complete documentation index, see [llms.txt](https://docs.chamilo.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.chamilo.org/administration-guide/admin-guide/authentication.md).

# Authentication

Chamilo supports multiple authentication methods, from the built-in username/password system to enterprise single sign-on solutions.

## Configuration file

All external authentication methods are configured in `config/authentication.yaml`. A template is provided at `config/authentication.dist.yaml`. The general structure is:

```yaml
parameters:
  authentication:
    <access_url_id>:
      <auth_method>:
        <provider_name>:
          <config_key>: <value>
```

After editing the file, clear and warm the cache:

```bash
php bin/console cache:clear
php bin/console cache:warmup
```

External login buttons appear on the login page after the cache is refreshed.

## Supported methods

* [**OAuth2**](/administration-guide/admin-guide/authentication/oauth2.md) — Azure AD, Keycloak, Facebook, and generic OAuth2 providers
* [**LDAP**](/administration-guide/admin-guide/authentication/ldap.md) — Authenticate against an LDAP or Active Directory server
* [**CAS**](/administration-guide/admin-guide/authentication/cas.md) — Central Authentication Service (legacy, not functional in 2.x)
* [**SCIM**](/administration-guide/admin-guide/authentication/scim.md) — Automated user provisioning from external identity providers
* [**SSO Configuration**](/administration-guide/admin-guide/authentication/sso-configuration.md) — Troubleshooting and cross-method notes

## Default authentication

By default, Chamilo uses its own internal system — users log in with a username and password stored in the Chamilo database. External methods are additive: the standard login form stays available alongside any configured providers.

## Further reference

For full parameter reference and advanced scenarios, see the [External Authentication configuration wiki page](https://github.com/chamilo/chamilo-lms/wiki/External-Authentication-configuration).