diff --git a/lib/PushEvent.php b/lib/PushEvent.php
index 5bf98ca..043a86e 100644
--- a/lib/PushEvent.php
+++ b/lib/PushEvent.php
@@ -8,45 +8,18 @@ use Psr\Http\Message\{UriInterface};
 
 /**
  * Represents a Gitea push event.
- * @property \ArrayObject $commits The revision commits.
- * @property UriInterface|null $compareUrl The URL for comparing the revisions.
  */
-class PushEvent {
+class PushEvent implements \JsonSerializable {
 
   /**
    * @var string The hash of the new Git revision.
    */
-  public $after = '';
+  private $after = '';
 
   /**
    * @var string The hash of the previous Git revision.
    */
-  public $before = '';
-
-  /**
-   * @var User|null The user who pushed the commits.
-   */
-  public $pusher;
-
-  /**
-   * @var string The Git reference.
-   */
-  public $ref = '';
-
-  /**
-   * @var Repository|null The repository where the commits were pushed.
-   */
-  public $repository;
-
-  /**
-   * @var string The secret used to validate this event.
-   */
-  public $secret = '';
-
-  /**
-   * @var User|null The user who sent this event.
-   */
-  public $sender;
+  private $before = '';
 
   /**
    * @var \ArrayObject The revision commits.
@@ -58,6 +31,31 @@ class PushEvent {
    */
   private $compareUrl;
 
+  /**
+   * @var User|null The user who pushed the commits.
+   */
+  private $pusher;
+
+  /**
+   * @var string The Git reference.
+   */
+  private $ref = '';
+
+  /**
+   * @var Repository|null The repository where the commits were pushed.
+   */
+  private $repository;
+
+  /**
+   * @var string The secret used to validate this event.
+   */
+  private $secret = '';
+
+  /**
+   * @var User|null The user who sent this event.
+   */
+  private $sender;
+
   /**
    * Creates a new event.
    * @param array $config Name-value pairs that will be used to initialize the object properties.
@@ -86,20 +84,19 @@ class PushEvent {
   }
 
   /**
-   * Returns the list of fields that should be returned by default.
-   * @return array The list of field names or field definitions.
+   * Gets the hash of the new Git revision.
+   * @return string The hash of the new Git revision.
    */
-  function fields(): array {
-    return [
-      'after',
-      'before',
-      'compare_url' => function(self $model) { return ($url = $model->getCompareUrl()) ? (string) $url : null; },
-      'commits',
-      'pusher',
-      'ref',
-      'repository',
-      'sender'
-    ];
+  function getAfter(): string {
+    return $this->after;
+  }
+
+  /**
+   * Gets the hash of the new previous revision.
+   * @return string The hash of the previous Git revision.
+   */
+  function getBefore(): string {
+    return $this->before;
   }
 
   /**
@@ -118,6 +115,59 @@ class PushEvent {
     return $this->compareUrl;
   }
 
+  /**
+   * Gets the Git reference.
+   * @return string The Git reference.
+   */
+  function getRef(): string {
+    return $this->ref;
+  }
+
+  /**
+   * Gets the secret used to validate this event.
+   * @return string The secret used to validate this event.
+   */
+  function getSecret(): string {
+    return $this->secret;
+  }
+
+  /**
+   * Converts this object to a map in JSON format.
+   * @return \stdClass The map in JSON format corresponding to this object.
+   */
+  function jsonSerialize(): \stdClass {
+    return (object) [
+      'after' => $this->getAfter(),
+      'before' => $this->getBefore(),
+      'compare_url' => ($url = $this->getCompareUrl()) ? (string) $url : null,
+      'commits' => array_map(function(PayloadCommit $commit) { return $commit->jsonSerialize(); }, $this->getCommits()->getArrayCopy()),
+      'pusher',
+      'ref' => $this->getRef(),
+      'repository',
+      'sender'
+    ];
+  }
+
+  /**
+   * Sets the hash of the new Git revision.
+   * @param string $value The hash of the new Git revision.
+   * @return $this This instance.
+   */
+  function setAfter(string $value): self {
+    $this->after = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the hash of the new previous revision.
+   * @param string $value The hash of the new previous revision.
+   * @return $this This instance.
+   */
+  function setBefore(string $value): self {
+    $this->before = $value;
+    return $this;
+  }
+
   /**
    * Sets the revision commits.
    * @param PayloadCommit[] $values The revision commits.
@@ -137,4 +187,24 @@ class PushEvent {
     $this->compareUrl = is_string($value) ? new Uri($value) : $value;
     return $this;
   }
+
+  /**
+   * Sets the Git reference.
+   * @param string $value The new Git reference.
+   * @return $this This instance.
+   */
+  function setRef(string $value): self {
+    $this->ref = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the secret used to validate this event.
+   * @param string $value The new secret used to validate this event.
+   * @return $this This instance.
+   */
+  function setSecret(string $value): self {
+    $this->secret = $value;
+    return $this;
+  }
 }
diff --git a/lib/models/PayloadCommit.php b/lib/models/PayloadCommit.php
index c80826b..31163e5 100644
--- a/lib/models/PayloadCommit.php
+++ b/lib/models/PayloadCommit.php
@@ -7,10 +7,8 @@ use Psr\Http\Message\{UriInterface};
 
 /**
  * Represents a commit.
- * @property \DateTime|null $timestamp The commit date.
- * @property UriInterface|null $url The URL to the commit's history.
  */
-class PayloadCommit {
+class PayloadCommit implements \JsonSerializable {
 
   /**
    * @var PayloadUser|null The person who authored the commit.
@@ -64,22 +62,6 @@ class PayloadCommit {
     ]);
   }
 
-  /**
-   * Returns the list of fields that should be returned by default.
-   * @return array The list of field names or field definitions.
-   */
-  function fields(): array {
-    return [
-      'author',
-      'committer',
-      'id',
-      'message',
-      'timestamp' => function(PayloadCommit $model) { return ($date = $model->getTimestamp()) ? $date->format('c') : null; },
-      'url' => function(self $model) { return ($url = $model->getUrl()) ? (string) $url : null; },
-      'verification'
-    ];
-  }
-
   /**
    * Gets the commit date.
    * @return \DateTime|null The commit date.
@@ -96,6 +78,22 @@ class PayloadCommit {
     return $this->url;
   }
 
+  /**
+   * Converts this object to a map in JSON format.
+   * @return \stdClass The map in JSON format corresponding to this object.
+   */
+  function jsonSerialize(): \stdClass {
+    return (object) [
+      'author',
+      'committer',
+      'id',
+      'message',
+      'timestamp' => ($date = $this->getTimestamp()) ? $date->format('c') : null,
+      'url' => ($url = $this->getUrl()) ? (string) $url : null,
+      'verification'
+    ];
+  }
+
   /**
    * Sets the commit date.
    * @param \DateTime|string|null $value The new commit date.
diff --git a/lib/models/PayloadCommitVerification.php b/lib/models/PayloadCommitVerification.php
index 9c775ad..dbfd12d 100644
--- a/lib/models/PayloadCommitVerification.php
+++ b/lib/models/PayloadCommitVerification.php
@@ -5,7 +5,7 @@ namespace Gitea\Models;
 /**
  * Represents the GPG verification of a commit.
  */
-class PayloadCommitVerification {
+class PayloadCommitVerification implements \JsonSerializable {
 
   /**
    * @var bool Value indicating whether the verification has succeeded.
@@ -42,11 +42,11 @@ class PayloadCommitVerification {
   }
 
   /**
-   * Returns the list of fields that should be returned by default.
-   * @return array The list of field names or field definitions.
+   * Converts this object to a map in JSON format.
+   * @return \stdClass The map in JSON format corresponding to this object.
    */
-  function fields(): array {
-    return [
+  function jsonSerialize(): \stdClass {
+    return (object) [
       'payload',
       'reason',
       'signature',
diff --git a/lib/models/Repository.php b/lib/models/Repository.php
index 136465b..f4aafbc 100644
--- a/lib/models/Repository.php
+++ b/lib/models/Repository.php
@@ -7,14 +7,8 @@ use Psr\Http\Message\{UriInterface};
 
 /**
  * Represents a repository.
- * @property UriInterface|null $cloneUrl The HTTP-based URL for cloning this repository.
- * @property \DateTime|null $createdAt The date the repository was created.
- * @property UriInterface|null $htmlUrl The Gitea URL of this repository.
- * @property UriInterface|null $sshUrl The SSH-based URL for cloning this repository.
- * @property \DateTime|null $updatedAt The date the repository was updated.
- * @property UriInterface|null $website The URL of the repository website.
  */
-class Repository {
+class Repository implements \JsonSerializable {
 
   /**
    * @var string The name of the default branch.
@@ -164,38 +158,6 @@ class Repository {
     ]);
   }
 
-  /**
-   * Returns the list of fields that should be returned by default.
-   * @return array The list of field names or field definitions.
-   */
-  function fields(): array {
-    return [
-      'clone_url' => function(self $model) { return ($url = $model->getCloneUrl()) ? (string) $url : null; },
-      'created_at' => function(Repository $model) { return ($date = $model->getCreatedAt()) ? $date->format('c') : null; },
-      'default_branch' => 'defaultBranch',
-      'description',
-      'empty' => 'isEmpty',
-      'fork' => 'isFork',
-      'forks_count' => 'forksCount',
-      'full_name' => 'fullName',
-      'html_url' => function(self $model) { return ($url = $model->getHtmlUrl()) ? (string) $url : null; },
-      'id',
-      'mirror' => 'isMirror',
-      'name',
-      'open_issues_count' => 'openIssuesCount',
-      'owner',
-      'parent',
-      'permissions',
-      'private' => 'isPrivate',
-      'size',
-      'ssh_url' => function(self $model) { return ($url = $model->getSshUrl()) ? (string) $url : null; },
-      'stars_count' => 'starsCount',
-      'updated_at' => function(Repository $model) { return ($date = $model->getUpdatedAt()) ? $date->format('c') : null; },
-      'watchers_count' => 'watchersCount',
-      'website' => function(self $model) { return ($url = $model->getWebsite()) ? (string) $url : null; },
-    ];
-  }
-
   /**
    * Gets the HTTP-based URL for cloning this repository.
    * @return UriInterface|null The HTTP-based URL for cloning this repository.
@@ -244,6 +206,38 @@ class Repository {
     return $this->website;
   }
 
+  /**
+   * Converts this object to a map in JSON format.
+   * @return \stdClass The map in JSON format corresponding to this object.
+   */
+  function jsonSerialize(): \stdClass {
+    return (object) [
+      'clone_url' => ($url = $this->getCloneUrl()) ? (string) $url : null,
+      'created_at' => ($date = $this->getCreatedAt()) ? $date->format('c') : null,
+      'default_branch' => 'defaultBranch',
+      'description',
+      'empty' => 'isEmpty',
+      'fork' => 'isFork',
+      'forks_count' => 'forksCount',
+      'full_name' => 'fullName',
+      'html_url' => ($url = $this->getHtmlUrl()) ? (string) $url : null,
+      'id',
+      'mirror' => 'isMirror',
+      'name',
+      'open_issues_count' => 'openIssuesCount',
+      'owner',
+      'parent',
+      'permissions',
+      'private' => 'isPrivate',
+      'size',
+      'ssh_url' => ($url = $this->getSshUrl()) ? (string) $url : null,
+      'stars_count' => 'starsCount',
+      'updated_at' => ($date = $this->getUpdatedAt()) ? $date->format('c') : null,
+      'watchers_count' => 'watchersCount',
+      'website' => ($url = $this->getWebsite()) ? (string) $url : null,
+    ];
+  }
+
   /**
    * Sets the HTTP-based URL for cloning this repository.
    * @param UriInterface|string|null $value The new URL for cloning this repository.
diff --git a/lib/models/User.php b/lib/models/User.php
index 4f385a3..ee469ac 100644
--- a/lib/models/User.php
+++ b/lib/models/User.php
@@ -7,40 +7,39 @@ use Psr\Http\Message\{UriInterface};
 
 /**
  * Represents a Gitea user.
- * @property UriInterface|null $avatarUrl The URL of the avatar image.
  */
-class User {
-
-  /**
-   * @var string The mail address.
-   */
-  public $email = '';
-
-  /**
-   * @var string The full name.
-   */
-  public $fullName = '';
-
-  /**
-   * @var int The user identifier.
-   */
-  public $id = -1;
-
-  /**
-   * @var string The user locale.
-   */
-  public $language = '';
-
-  /**
-   * @var string The name of the Gitea account.
-   */
-  public $login = '';
+class User implements \JsonSerializable {
 
   /**
    * @var UriInterface|null The URL to the user's avatar.
    */
   private $avatarUrl;
 
+  /**
+   * @var string The mail address.
+   */
+  private $email = '';
+
+  /**
+   * @var string The full name.
+   */
+  private $fullName = '';
+
+  /**
+   * @var int The user identifier.
+   */
+  private $id = -1;
+
+  /**
+   * @var string The user locale.
+   */
+  private $language = '';
+
+  /**
+   * @var string The name of the Gitea account.
+   */
+  private $login = '';
+
   /**
    * Creates a new user from the specified JSON map.
    * @param object $map A JSON map representing a user.
@@ -57,21 +56,6 @@ class User {
     ]);
   }
 
-  /**
-   * Returns the list of fields that should be returned by default.
-   * @return array The list of field names or field definitions.
-   */
-  function fields(): array {
-    return [
-      'avatar_url' => function(self $model) { return ($url = $model->getAvatarUrl()) ? (string) $url : null; },
-      'email',
-      'full_name' => 'fullName',
-      'id',
-      'language',
-      'login'
-    ];
-  }
-
   /**
    * Gets the URL of the avatar image.
    * @return UriInterface|null The URL of the avatar image.
@@ -80,6 +64,61 @@ class User {
     return $this->avatarUrl;
   }
 
+  /**
+   * Gets the mail address.
+   * @return string The mail address.
+   */
+  function getEmail(): string {
+    return $this->email;
+  }
+
+  /**
+   * Gets the full name.
+   * @return string The full name.
+   */
+  function getFullName(): string {
+    return $this->fullName;
+  }
+
+  /**
+   * Gets the user identifier.
+   * @return int The user identifier.
+   */
+  function getId(): int {
+    return $this->id;
+  }
+
+  /**
+   * Gets the user locale.
+   * @return string The user locale.
+   */
+  function getLanguage(): string {
+    return $this->language;
+  }
+
+  /**
+   * Gets the name of the Gitea account.
+   * @return string The name of the Gitea account.
+   */
+  function getLogin(): string {
+    return $this->login;
+  }
+
+  /**
+   * Converts this object to a map in JSON format.
+   * @return \stdClass The map in JSON format corresponding to this object.
+   */
+  function jsonSerialize(): \stdClass {
+    return (object) [
+      'avatar_url' => ($url = $this->getAvatarUrl()) ? (string) $url : null,
+      'email' => $this->getEmail(),
+      'full_name' => $this->getFullName(),
+      'id' => $this->getId(),
+      'language' => $this->getLanguage(),
+      'login' => $this->getLogin()
+    ];
+  }
+
   /**
    * Sets the URL of the avatar image.
    * @param UriInterface|string|null $value The new avatar URL.
@@ -89,4 +128,54 @@ class User {
     $this->avatarUrl = is_string($value) ? new Uri($value) : $value;
     return $this;
   }
+
+  /**
+   * Sets the mail address.
+   * @param string $value The new mail address.
+   * @return $this This instance.
+   */
+  function setEmail(string $value): self {
+    $this->email = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the full name.
+   * @param string $value The new full name.
+   * @return $this This instance.
+   */
+  function setFullName(string $value): self {
+    $this->fullName = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the user identifier.
+   * @param int $value The new user identifier.
+   * @return $this This instance.
+   */
+  function setId(int $value): self {
+    $this->id = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the user locale.
+   * @param string $value The new user locale.
+   * @return $this This instance.
+   */
+  function setLanguage(string $value): self {
+    $this->language = $value;
+    return $this;
+  }
+
+  /**
+   * Sets the name of the Gitea account.
+   * @param string $value The new Gitea account.
+   * @return $this This instance.
+   */
+  function setLogin(string $value): self {
+    $this->login = $value;
+    return $this;
+  }
 }