Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

///

## Dataclasses in `response_model` { #dataclasses-in-response-model }

You can also use `dataclasses` in the `response_model` parameter:

<!--
 | This is the toolchains file for Maven. It can be specified at two levels:
 |
 |  1. User Level. This toolchains.xml file provides configuration for a single user,
 |                 and is normally provided in ${user.home}/.m2/toolchains.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -t /path/to/user/toolchains.xml
 |
 |  2. Installation Level.

    public String id;

    /**
     * The username of the user who last updated this group.
     * Used for audit trail purposes to track who made changes.
     */
    @Size(max = 1000)
    public String updatedBy;

    /**
     * The timestamp when this group was last updated.
     * Stored as a long value representing milliseconds since epoch.
     * Used for audit trail and concurrency control.
     */

```plaintext
/home/user/code/awesome-project/.venv/bin/python
```

and use that one.

////

//// tab | Windows

```plaintext
C:\Users\user\code\awesome-project\.venv\Scripts;C:\Windows\System32
```

That means that the system will now start looking first for programs in:

```plaintext
C:\Users\user\code\awesome-project\.venv\Scripts
```

            return userCode;
        }).orElse(null);
    }

    /**
     * Extracts the user code from the user bean stored in the session.
     * This method retrieves the authenticated user information and creates an encrypted user code.
     *
     * @param request the HTTP servlet request
     * @return the user code from the user bean, or null if not found or invalid
     */

    }

    /** Logger for this class */
    private static final Logger logger = LogManager.getLogger(QueryHelper.class);

    /** Constant used to indicate that query-based preference should be used for search routing */
    protected static final String PREFERENCE_QUERY = "_query";

    /** Prefix used to identify sort parameters in search queries */
    protected String sortPrefix = "sort:";

            Specifies that this parameter can be configured directly by the user (as in the case of POM-specified
            configuration). This is useful when you want to force the user to use common POM elements rather than
            plugin configurations, as in the case where you want to use the artifact's final name as a parameter. In
            this case, you want the user to modify {@code <build><finalName/></build>} rather

 not sure the unified source directory structure addresses this issue.

 Properties

 maven.user.config.dir (system,default=${user.home}/.m2)
 maven.home            (system,user,default=${user.home}/m2)
 maven.repo.local      (system,user,default=${maven.user.config.dir}/repository)

 We need to define what happens in the when things are not setup correctly

 o ~/.m2 directory does not exist

/**
 * Exception thrown when user role authentication fails during login attempts.
 * This exception is used to indicate that a user does not have the required role
 * to access a specific action or resource.
 *
 */
public class UserRoleLoginException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    /** The action class that requires specific user roles */

     */
    public UserInfoService() {
        // Default constructor
    }

    /**
     * Deletes user information records older than the specified number of days.
     * This method is used for data cleanup and maintenance operations.
     *
     * @param days the number of days to keep user information records
     */
    public void deleteBefore(final int days) {
        userInfoBhv.queryDelete(cb -> {