diff --git a/database/migrations/structure/20230411_2004_oauth_restrictions.sql b/database/migrations/structure/20230411_2004_oauth_restrictions.sql
new file mode 100644
index 0000000..410ce96
--- /dev/null
+++ b/database/migrations/structure/20230411_2004_oauth_restrictions.sql
@@ -0,0 +1,10 @@
+CREATE TABLE `oauth_clients` (
+  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
+  `client_id` varchar(16) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+  `client_secret` varchar(40) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+  `redirect_uris` text NOT NULL,
+  `preapproved` tinyint(1) NOT NULL DEFAULT 0,
+  `created` timestamp NOT NULL DEFAULT current_timestamp(),
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `client_id` (`client_id`)
+) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;
diff --git a/rvr b/rvr
index 4901de4..bd396bd 100755
--- a/rvr
+++ b/rvr
@@ -9,5 +9,8 @@ $app->add(new RVR\Cli\MigrateDatabaseCommand());
 $app->add(new RVR\Cli\AddUserCommand());
 $app->add(new RVR\Cli\LinkViewCommand());
 $app->add(new RVR\Cli\MaintainDatabaseCommand());
+$app->add(new RVR\Cli\AddOAuthClientCommand());
+$app->add(new RVR\Cli\AddOAuthRedirectUriCommand());
+$app->add(new RVR\Cli\RemoveOAuthRedirectUriCommand());
 
 $app->run();
diff --git a/src/Cli/AddOAuthClientCommand.php b/src/Cli/AddOAuthClientCommand.php
new file mode 100644
index 0000000..9e1d329
--- /dev/null
+++ b/src/Cli/AddOAuthClientCommand.php
@@ -0,0 +1,53 @@
+<?php namespace RVR\Cli;
+
+use DateTime;
+use SokoWeb\PersistentData\PersistentDataManager;
+use RVR\PersistentData\Model\OAuthClient;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class AddOAuthClientCommand extends Command
+{
+    public function configure(): void
+    {
+        $this->setName('oauth:add-client')
+            ->setDescription('Adding of OAuth client.')
+            ->addArgument('preapproved', InputArgument::OPTIONAL, 'Preapproved');
+    }
+
+    public function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $clientId = bin2hex(random_bytes(8));
+        $clientSecret = bin2hex(random_bytes(20));
+
+        $oAuthClient = new OAuthClient();
+        $oAuthClient->setClientId($clientId);
+        $oAuthClient->setClientSecret($clientSecret);
+        $oAuthClient->setCreatedDate(new DateTime());
+
+        if ($input->hasArgument('preapproved') && $input->getArgument('preapproved')) {
+            $oAuthClient->setPreapproved($input->getArgument('preapproved'));
+        }
+
+        try {
+            $pdm = new PersistentDataManager();
+            $pdm->saveToDb($oAuthClient);
+        } catch (\Exception $e) {
+            $output->writeln('<error>Adding OAuth client failed!</error>');
+            $output->writeln('');
+
+            $output->writeln((string) $e);
+            $output->writeln('');
+
+            return 1;
+        }
+
+        $output->writeln('<info>OAuth client was successfully added!</info>');
+        $output->writeln('<info>Client ID: ' . $clientId . '</info>');
+        $output->writeln('<info>Client secret: ' . $clientSecret . '</info>');
+
+        return 0;
+    }
+}
diff --git a/src/Cli/AddOAuthRedirectUriCommand.php b/src/Cli/AddOAuthRedirectUriCommand.php
new file mode 100644
index 0000000..276e46a
--- /dev/null
+++ b/src/Cli/AddOAuthRedirectUriCommand.php
@@ -0,0 +1,54 @@
+<?php namespace RVR\Cli;
+
+use SokoWeb\PersistentData\PersistentDataManager;
+use RVR\Repository\OAuthClientRepository;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class AddOAuthRedirectUriCommand extends Command
+{
+    public function configure(): void
+    {
+        $this->setName('oauth:add-redirect-uri')
+            ->setDescription('Adding of redirect URI for OAuth client.')
+            ->addArgument('client_id', InputArgument::REQUIRED, 'The OAuth client ID')
+            ->addArgument('redirect_uris', InputArgument::IS_ARRAY, 'Redirect URIs to add');
+    }
+
+    public function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $oAuthClientRepository = new OAuthClientRepository();
+        $oAuthClient = $oAuthClientRepository->getByClientId($input->getArgument('client_id'));
+
+        if ($oAuthClient === null) {
+            $output->writeln('<error>OAuth client does not exist!</error>');
+            return 1;
+        }
+
+        $redirectUris = array_unique(array_merge($oAuthClient->getRedirectUrisArray(), $input->getArgument('redirect_uris')));
+
+        $oAuthClient->setRedirectUrisArray($redirectUris);
+
+        try {
+            $pdm = new PersistentDataManager();
+            $pdm->saveToDb($oAuthClient);
+        } catch (\Exception $e) {
+            $output->writeln('<error>Adding redirect URI failed!</error>');
+            $output->writeln('');
+
+            $output->writeln((string) $e);
+            $output->writeln('');
+
+            return 1;
+        }
+
+        $redirectUrisToPrint = [];
+        foreach ($redirectUris as $redirectUri) $redirectUrisToPrint[] = '* ' . $redirectUri;
+
+        $output->writeln('<info>Redirect URIS were successfully added! Current URIs:' . "\n" . implode("\n", $redirectUrisToPrint) . '</info>');
+
+        return 0;
+    }
+}
diff --git a/src/Cli/RemoveOAuthRedirectUriCommand.php b/src/Cli/RemoveOAuthRedirectUriCommand.php
new file mode 100644
index 0000000..c784a8d
--- /dev/null
+++ b/src/Cli/RemoveOAuthRedirectUriCommand.php
@@ -0,0 +1,54 @@
+<?php namespace RVR\Cli;
+
+use SokoWeb\PersistentData\PersistentDataManager;
+use RVR\Repository\OAuthClientRepository;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class RemoveOAuthRedirectUriCommand extends Command
+{
+    public function configure(): void
+    {
+        $this->setName('oauth:remove-redirect-uri')
+            ->setDescription('Removing of redirect URI for OAuth client.')
+            ->addArgument('client_id', InputArgument::REQUIRED, 'The OAuth client ID')
+            ->addArgument('redirect_uris', InputArgument::IS_ARRAY, 'Redirect URIs to remove');
+    }
+
+    public function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $oAuthClientRepository = new OAuthClientRepository();
+        $oAuthClient = $oAuthClientRepository->getByClientId($input->getArgument('client_id'));
+
+        if ($oAuthClient === null) {
+            $output->writeln('<error>OAuth client does not exist!</error>');
+            return 1;
+        }
+
+        $redirectUris = array_diff($oAuthClient->getRedirectUrisArray(), $input->getArgument('redirect_uris'));
+
+        $oAuthClient->setRedirectUrisArray($redirectUris);
+
+        try {
+            $pdm = new PersistentDataManager();
+            $pdm->saveToDb($oAuthClient);
+        } catch (\Exception $e) {
+            $output->writeln('<error>Removing redirect URI failed!</error>');
+            $output->writeln('');
+
+            $output->writeln((string) $e);
+            $output->writeln('');
+
+            return 1;
+        }
+
+        $redirectUrisToPrint = [];
+        foreach ($redirectUris as $redirectUri) $redirectUrisToPrint[] = '* ' . $redirectUri;
+
+        $output->writeln('<info>Redirect URIS were successfully removed! Current URIs:' . "\n" . implode("\n", $redirectUrisToPrint) . '</info>');
+
+        return 0;
+    }
+}
diff --git a/src/Controller/OAuthAuthController.php b/src/Controller/OAuthAuthController.php
index f68b4c0..7dd983a 100644
--- a/src/Controller/OAuthAuthController.php
+++ b/src/Controller/OAuthAuthController.php
@@ -3,6 +3,7 @@
 use DateTime;
 use RVR\PersistentData\Model\OAuthToken;
 use RVR\PersistentData\Model\User;
+use RVR\Repository\OAuthClientRepository;
 use SokoWeb\Interfaces\Authorization\ISecured;
 use SokoWeb\Interfaces\Request\IRequest;
 use SokoWeb\Interfaces\Response\IRedirect;
@@ -16,10 +17,13 @@ class OAuthAuthController implements ISecured
 
     private PersistentDataManager $pdm;
 
+    private OAuthClientRepository $oAuthClientRepository;
+
     public function __construct(IRequest $request)
     {
         $this->request = $request;
         $this->pdm = new PersistentDataManager();
+        $this->oAuthClientRepository = new OAuthClientRepository();
     }
 
     public function authorize(): bool
@@ -30,15 +34,30 @@ class OAuthAuthController implements ISecured
     public function auth()
     {
         $redirectUri = $this->request->query('redirect_uri');
+        $clientId = $this->request->query('client_id');
         $scope = $this->request->query('scope') ? $this->request->query('scope'): '';
         $state = $this->request->query('state');
         $nonce = $this->request->query('nonce') ? $this->request->query('nonce'): '';
 
-        if (!$redirectUri || !$state) {
+        if (!$clientId || !$redirectUri || !$state) {
             return new HtmlContent('oauth/oauth_error', ['error' => 'An invalid request was made. Please start authentication again.']);
         }
 
-        $this->request->session()->delete('oauth_payload');
+        $client = $this->oAuthClientRepository->getByClientId($clientId);
+        if ($client === null) {
+            return new HtmlContent('oauth/oauth_error', ['error' => 'Client is not authorized.']);
+        }
+
+        $redirectUriParsed = parse_url($redirectUri);
+        $redirectUriBase = $redirectUriParsed['scheme'] . '://' . $redirectUriParsed['host'] . $redirectUriParsed['path'];
+        $redirectUriQuery = [];
+        if (isset($redirectUriParsed['query'])) {
+            parse_str($redirectUriParsed['query'], $redirectUriQuery);
+        }
+
+        if (!in_array($redirectUriBase, $client->getRedirectUrisArray())) {
+            return new HtmlContent('oauth/oauth_error', ['error' => 'Redirect URI \'' . $redirectUriBase .'\' is not allowed for this client.']);
+        }
 
         /**
         * @var ?User $user
@@ -57,13 +76,11 @@ class OAuthAuthController implements ISecured
         $token->setExpiresDate(new DateTime('+5 minutes'));
         $this->pdm->saveToDb($token);
 
-        $redirectUri = $redirectUri;
-        $additionalUriParams = [
+        $redirectUriQuery = array_merge($redirectUriQuery, [
             'state' => $state,
             'code' => $code
-        ];
-        $and = (strpos($redirectUri, '?') !== false) ? '&' : '?';
-        $finalRedirectUri = $redirectUri . $and .  http_build_query($additionalUriParams);
+        ]);
+        $finalRedirectUri = $redirectUriBase . '?' . http_build_query($redirectUriQuery);
 
         return new Redirect($finalRedirectUri, IRedirect::TEMPORARY);
     }
diff --git a/src/Controller/OAuthController.php b/src/Controller/OAuthController.php
index bd3845c..abd7a70 100644
--- a/src/Controller/OAuthController.php
+++ b/src/Controller/OAuthController.php
@@ -5,6 +5,7 @@ use Firebase\JWT\JWT;
 use RVR\Repository\OAuthTokenRepository;
 use RVR\Repository\UserRepository;
 use RVR\PersistentData\Model\User;
+use RVR\Repository\OAuthClientRepository;
 use SokoWeb\Interfaces\Request\IRequest;
 use SokoWeb\Interfaces\Response\IContent;
 use SokoWeb\Response\JsonContent;
@@ -13,6 +14,8 @@ class OAuthController
 {
     private IRequest $request;
 
+    private OAuthClientRepository $oAuthClientRepository;
+
     private OAuthTokenRepository $oAuthTokenRepository;
 
     private UserRepository $userRepository;
@@ -20,14 +23,31 @@ class OAuthController
     public function __construct(IRequest $request)
     {
         $this->request = $request;
+        $this->oAuthClientRepository = new OAuthClientRepository();
         $this->oAuthTokenRepository = new OAuthTokenRepository();
         $this->userRepository = new UserRepository();
     }
 
     public function getToken(): ?IContent
     {
-        $token = $this->oAuthTokenRepository->getByCode($this->request->post('code'));
+        $clientId = $this->request->post('client_id');
+        $clientSecret = $this->request->post('client_secret');
+        $code = $this->request->post('code');
 
+        if (!$clientId || !$clientSecret || !$code) {
+            return new JsonContent([
+                'error' => 'An invalid request was made.'
+            ]);
+        }
+
+        $client = $this->oAuthClientRepository->getByClientId($clientId);
+        if ($client === null || $client->getClientSecret() !== $clientSecret) {
+            return new JsonContent([
+                'error' => 'Client is not authorized.'
+            ]);
+        }
+
+        $token = $this->oAuthTokenRepository->getByCode($code);
         if ($token === null || $token->getExpiresDate() < new DateTime()) {
             return new JsonContent([
                 'error' => 'The provided code is invalid.'
diff --git a/src/PersistentData/Model/OAuthClient.php b/src/PersistentData/Model/OAuthClient.php
new file mode 100644
index 0000000..80573a8
--- /dev/null
+++ b/src/PersistentData/Model/OAuthClient.php
@@ -0,0 +1,91 @@
+<?php namespace RVR\PersistentData\Model;
+
+use DateTime;
+use SokoWeb\PersistentData\Model\Model;
+
+class OAuthClient extends Model
+{
+    protected static string $table = 'oauth_clients';
+
+    protected static array $fields = ['client_id', 'client_secret', 'redirect_uris', 'preapproved', 'created'];
+
+    private string $clientId = '';
+
+    private string $clientSecret = '';
+
+    private array $redirectUris = [];
+
+    private bool $preapproved = false;
+
+    private DateTime $created;
+
+    public function setClientId(string $clientId): void
+    {
+        $this->clientId = $clientId;
+    }
+
+    public function setClientSecret(string $clientSecret): void
+    {
+        $this->clientSecret = $clientSecret;
+    }
+
+    public function setRedirectUrisArray(array $redirectUris): void
+    {
+        $this->redirectUris = $redirectUris;
+    }
+
+    public function setRedirectUris(string $redirectUris): void
+    {
+        $this->redirectUris = json_decode($redirectUris, true);
+    }
+
+    public function setPreapproved(bool $preapproved): void
+    {
+        $this->preapproved = $preapproved;
+    }
+
+    public function setCreatedDate(DateTime $created): void
+    {
+        $this->created = $created;
+    }
+
+    public function setCreated(string $created): void
+    {
+        $this->created = new DateTime($created);
+    }
+
+    public function getClientId(): string
+    {
+        return $this->clientId;
+    }
+
+    public function getClientSecret(): string
+    {
+        return $this->clientSecret;
+    }
+
+    public function getRedirectUrisArray(): array
+    {
+        return $this->redirectUris;
+    }
+
+    public function getRedirectUris(): string
+    {
+        return json_encode($this->redirectUris);
+    }
+
+    public function getPreapproved(): bool
+    {
+        return $this->preapproved;
+    }
+
+    public function getCreatedDate(): DateTime
+    {
+        return $this->created;
+    }
+
+    public function getCreated(): string
+    {
+        return $this->created->format('Y-m-d H:i:s');
+    }
+}
diff --git a/src/Repository/OAuthClientRepository.php b/src/Repository/OAuthClientRepository.php
new file mode 100644
index 0000000..ba99961
--- /dev/null
+++ b/src/Repository/OAuthClientRepository.php
@@ -0,0 +1,28 @@
+<?php namespace RVR\Repository;
+
+use SokoWeb\Database\Query\Select;
+use RVR\PersistentData\Model\OAuthClient;
+use SokoWeb\PersistentData\PersistentDataManager;
+
+class OAuthClientRepository
+{
+    private PersistentDataManager $pdm;
+
+    public function __construct()
+    {
+        $this->pdm = new PersistentDataManager();
+    }
+
+    public function getById(int $id): ?OAuthClient
+    {
+        return $this->pdm->selectFromDbById($id, OAuthClient::class);
+    }
+
+    public function getByClientId(string $clientId): ?OAuthClient
+    {
+        $select = new Select(\Container::$dbConnection);
+        $select->where('client_id', '=', $clientId);
+
+        return $this->pdm->selectFromDb($select, OAuthClient::class);
+    }
+}