// ------------------------ Breaking changes ------------------------  //
== Breaking changes

= Loopback Hostname Verification on Windows

Setups on Windows that previously relied on custom machine names or non-standard hostnames for loopback (for example, `127.0.0.1` resolving to a custom name) may require updates to their trusted domain configuration. Only `localhost` and `*.localhost` are now recognized for loopback verification.

{project_name} now consistently normalizes loopback addresses to `localhost` for domain verification across all platforms. This change ensures predictable behavior for trusted domain checks, regardless of the underlying OS.

// ------------------------ Notable changes ------------------------ //
== Notable changes

Notable changes may include internal behavior changes that prevent common misconfigurations, bugs that are fixed, or changes to simplify running {project_name}.
It also lists significant changes to internal APIs.

=== Method `UserProfile#toRepresentation(boolean)` added

The `UserProfile` interface has a new method `toRepresentation(boolean)`. This method allows clients to specify whether to include
only the basic attributes in representations or all of them.

The `UserProfile` interface is a private API and should not be implemented by custom code. However, if you have extensions that
implement this interface, you will need to update your code to accommodate this new method.

Breaking changes are identified as those that might require changes for existing users to their configurations or applications.
In minor or patch releases, {project_name} will only introduce breaking changes to fix bugs.

=== Identity Provider refactoring

The private SPI for identity providers has been refactored. This is to allow identity providers to support more use
-cases than federated user authentication.

For anyone implementing a custom federated user authentication identity provider and are not extending one provided
by Keycloak or `AbstractIdentityProvider` you need to update your implementation to implement
the new `UserAuthenticationIdentityProvider` interface (all methods remain the same, they have just been moved).

Additionally, both `IdentityProviderModel` and `IdentityProviderRepresentation` are now using Boolean values to allow
configuration like `isHideOnLogin` to be null in order to not include these in Identity Provider types that do
not need these configurations.

=== SPIFFE Identity Provider configuration changed

The SPIFFE Identity Provider preview feature now uses the `trustDomain` configuration instead of `issuer`. This change
was done to make it more explicit that a `trustDomain` is configured and not the `iss` of the token, which is
usually not set in SPIFFE JWT SVIDs.

=== Running on Microsoft SQL Server now recommends READ_COMMITTED_SNAPSHOT

On MS SQL Server, the default transaction isolation level is `READ_COMMITTED`, which can lead to deadlocks during high load. Therefore, the recommended isolation level for {project_name} is `READ_COMMITTED_SNAPSHOT`.

Use the following statement to changes this for your database:

[source,sql]
----
ALTER DATABASE [your-database-name] SET READ_COMMITTED_SNAPSHOT ON;
----


=== `session_state` and `sid` are no longer UUIDs

In OpenID connect, there are several places where the protocol shares a `session_state` and a `sid`.
The specifications define it as an opaque string.
Previous versions of {project_name} used a UUID for it, while the current version now uses a random base64-encoded string.
The length of the string was reduced from 36 characters to 24 characters, although it might increase in the future if additional randomness is required.

=== `log-console-color` will automatically enable if supported by the terminal

The `log-console-color` previously defaulted to `false`, but it will now instead check if the terminal supports color.

You may still explicitly disable color support by setting the option to `false`.

=== Some message keys no longer support HTML entities

The following message keys in translations no longer support HTML entities: `backToLogin`, `backToApplication`, `proceedWithAction`.

The default themes have already been updated. If you used them in your translations, please update your translation to use the UTF-8 equivalent.

=== Permissions of the database user for PostgreSQL

If you are running on PostgreSQL as a database for {project_name}, ensure that the database user has `SELECT` permissions to the following tables to ensure an efficient upgrade: `pg_class`, `pg_namespace`.

This is used during upgrades of {project_name} to determine an estimated number of rows in a table.
If {project_name} does not have permissions to access these tables, it will log a warning and proceed with the less efficient `+SELECT COUNT(*) ...+` operation during the upgrade to determine the number of rows in tables affected by schema changes.

=== Expiration of login failures from the embedded caches

Previous entries in the `loginFailures` cache never expired, and entries accumulated as users entered wrong credentials, increasing the memory consumption.

Starting with this release, entries will expire based on the "`Failure reset time`" configured in the "`Brute force detection`" for the modes "`Lockout temporarily`" and "`Lockout permanently after temporary lockout`". For "`Lockout permanently`", entries will not expire as before, as this mode does not have a "`Failure reset time`".

=== Not recommended to use org.keycloak.credential.UserCredentialManager directly in your extensions

If you have user storage extension and you reference the class `org.keycloak.credential.UserCredentialManager` from your providers, it is recommended to avoid using this class directly as it might be
moved to the private modules in the future releases. The class may be typically used in the method `credentialManager()` of the implementations of `UserModel` interface. In that case,
it is recommended to replace the code like this:

[source,java]
----
@Override
public SubjectCredentialManager credentialManager() {
    return new UserCredentialManager(keycloakSession, realmModel, this);
}
----

with the code similar to this:

[source,java]
----
@Override
public org.keycloak.models.UserCredentialManager credentialManager() {
    return keycloakSession.users().getUserCredentialManager(this);
}
----

=== OCSP request timeouts follow HTTP client configuration

In previous versions, OCSP requests used hardcoded connection and socket timeouts of 10 seconds.
In this release, OCSP requests inherit timeouts from the outgoing HTTP client configuration (SPI `connections-http-client`, provider `default`).

- **Socket timeout property**: `socket-timeout-millis` (default: `5000`)
- **Establish connection timeout property**: `establish-connection-timeout-millis` (default: not set / `-1`)

If you relied on the previous 10-second behavior, explicitly set the HTTP client timeouts.

=== Default authorization policies and resources are no longer auto-created

When enabling authorization on a new client (creating a Resource Server), {project_name} no longer automatically creates a "`Default Resource`", a "`Default Policy`", and a "`Default Permission`".

=== Deleting expired sessions from the database

Previously, a single instance of {project_name} would check and remove expired entries using a cluster-aware scheduled task,
with each node attempting to trigger this task every 15 minutes.
This led to a situation that the more instances a cluster had, the more often this ran, although it would never run concurrently on two nodes at the same time.

Starting from this version, removal is handled by all {project_name} instances, with each instance handling the expiration of sessions in different realms.
Additionally, a new SPI option has been added to control the frequency of the internal deletion task: `--spi-user-sessions--infinispan--session-expiration-period` (value in seconds). By default, this runs every three minutes.
If you now add more instances to a clusters, the expiration is still run at the same interval.

Previously, {project_name} deleted sessions from the database only once the session idle time including the remember-me idle time had passed.

With the new setup and persistent user sessions enabled, sessions are deleted more timely based on the realm settings on session lifetime and idle time, including the remember me settings. For this, the table `OFFLINE_USER_SESSION` now has a new column `REMEMBER_ME`, that is filled for new sessions and updated incrementally for existing sessions.
The deletion is triggered currently three minutes after the session has expired to allow for clock skew between instances. Note that this interval can change in future release as we optimize this functionality.

This adds new indexes on `OFFLINE_USER_SESSION` table to improve performance when retrieving or deleting client sessions.

If those tables contain more than 300000 entries, {project_name} will skip the index creation by default during the automatic schema migration and instead log the SQL statement on the console during migration to be applied manually after {project_name}'s startup.
See the link:{upgradingguide_link}[{upgradingguide_name}] for details on how to configure a different limit.

For each expired user session there is a new user event `USER_SESSION_DELETED` fired.
As part of this change, the process now deletes rows from the table in small batches, instead of issuing a delete statements that affects the whole table. This should allow for better response times when there are a lot of sessions in the table.

// ------------------------ Deprecated features ------------------------ //
== Deprecated features

The following sections provide details on deprecated features.

=== `AuthenticationManager.AuthResult` is now a record

The inner class `AuthenticationManager.AuthResult` in the `keycloak-services` module is now a record.
The getter methods like `getSession()` have been deprecated in favor of the `session()` accessors.

=== Deprecation of methods for removing expired authentication sessions from `AuthenticationSessionProvider`

The methods `removeAllExpired()` and `removeExpired(RealmModel realm)` are annotated with the `@Deprecated` annotation.
They have been deprecated since {project_name} 19, as the built-in implementations now use their own internal cleanup mechanisms.
If you are providing a custom implementation of this provider, implement an internal mechanism to delete expired sessions.

=== Deprecation of methods for removing expired user sessions from `UserSessionProvider`

The methods `removeAllExpired()` and `removeExpired(RealmModel realm)` are deprecated.
A new internal cleanup mechanism has been implemented to automatically remove expired sessions from the database.
If you are providing a custom implementation of this provider, implement an internal mechanism to delete expired sessions.

=== Deprecation of cluster scheduled task `ClearExpiredUserSessions`

As `AuthenticationSessionProvider` and `UserSessionProvider` now have an internal mechanism to delete expired entries, the scheduled task `ClearExpiredUserSessions` has been deprecated.
It is still triggered in this {project_name} version, but will be removed in a future release.


=== Fine-Grained Admin Permissions (FGAP) v1

Fine-Grained Admin Permissions (FGAP) v1 is now deprecated. This version no longer receives enhancements and improvements  and will be removed in future
release. Please migrate to FGAP v2 to ensure continued support.

// ------------------------ Removed features ------------------------ //
== Removed features

=== PostgreSQL 13 (end of life)

Version PostgreSQL is end-of-life since November 2025 and therefore no longer supported.
