Initial commit

application/Espo/Core/Api/Action.php

@@ -0,0 +1,55 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Exceptions\Conflict;
+use Espo\Core\Exceptions\Error;
+use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Exceptions\NotFound;
+
+/**
+ * A route action.
+ */
+interface Action
+{
+    /**
+     * Process.
+     *
+     * @param Request $request A request.
+     * @return Response A response. Use ResponseComposer for building.
+     * @throws BadRequest
+     * @throws Forbidden
+     * @throws NotFound
+     * @throws Conflict
+     * @throws Error
+     */
+    public function process(Request $request): Response;
+}

application/Espo/Core/Api/ActionHandler.php

@@ -0,0 +1,122 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Exceptions\Conflict;
+use Espo\Core\Exceptions\Error;
+use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Exceptions\NotFound;
+
+use Espo\Core\Utils\Config;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ResponseInterface as Psr7Response;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use Slim\Psr7\Factory\ResponseFactory;
+
+/**
+ * @internal
+ */
+class ActionHandler implements RequestHandlerInterface
+{
+    private const DEFAULT_CONTENT_TYPE = 'application/json';
+
+    public function __construct(
+        private Action $action,
+        private ProcessData $processData,
+        private Config $config
+    ) {}
+
+    /**
+     * @throws BadRequest
+     * @throws Forbidden
+     * @throws Error
+     * @throws NotFound
+     * @throws Conflict
+     */
+    public function handle(ServerRequestInterface $request): ResponseInterface
+    {
+        $requestWrapped = new RequestWrapper(
+            $request,
+            $this->processData->getBasePath(),
+            $this->processData->getRouteParams()
+        );
+
+        $response = $this->action->process($requestWrapped);
+
+        return $this->prepareResponse($response);
+    }
+
+    private function prepareResponse(Response $response): Psr7Response
+    {
+        if (!$response->hasHeader('Content-Type')) {
+            $response->setHeader('Content-Type', self::DEFAULT_CONTENT_TYPE);
+        }
+
+        if (!$response->hasHeader('Cache-Control')) {
+            $response->setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
+        }
+
+        if (!$response->hasHeader('Expires')) {
+            $response->setHeader('Expires', '0');
+        }
+
+        if (!$response->hasHeader('Last-Modified')) {
+            $response->setHeader('Last-Modified', gmdate('D, d M Y H:i:s') . ' GMT');
+        }
+
+        $response->setHeader('X-App-Timestamp', (string) ($this->config->get('appTimestamp') ?? '0'));
+
+        /** @noinspection PhpConditionAlreadyCheckedInspection */
+        return $response instanceof ResponseWrapper ?
+            $response->toPsr7() :
+            self::responseToPsr7($response);
+    }
+
+    private static function responseToPsr7(Response $response): Psr7Response
+    {
+        $psr7Response = (new ResponseFactory())->createResponse();
+
+        $statusCode = $response->getStatusCode();
+        $reason = $response->getReasonPhrase();
+        $body = $response->getBody();
+
+        $psr7Response = $psr7Response
+            ->withStatus($statusCode, $reason)
+            ->withBody($body);
+
+        foreach ($response->getHeaderNames() as $name) {
+            $psr7Response = $psr7Response->withHeader($name, $response->getHeaderAsArray($name));
+        }
+
+        return $psr7Response;
+    }
+}

application/Espo/Core/Api/Auth.php

@@ -0,0 +1,347 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Authentication\HeaderKey;
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Exceptions\ServiceUnavailable;
+use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Authentication\ConfigDataProvider;
+use Espo\Core\Authentication\Authentication;
+use Espo\Core\Authentication\AuthenticationData;
+use Espo\Core\Authentication\Result;
+use Espo\Core\Utils\Log;
+use Espo\Core\Utils\Json;
+
+use Exception;
+
+/**
+ * Determines which auth method to use. Fetches a username and password from headers and server parameters.
+ * Then tries to log in.
+ */
+class Auth
+{
+    public function __construct(
+        private Log $log,
+        private Authentication $authentication,
+        private ConfigDataProvider $configDataProvider,
+        private bool $authRequired = true,
+        private bool $isEntryPoint = false
+    ) {}
+
+    /**
+     * @throws BadRequest
+     * @throws Exception
+     */
+    public function process(Request $request, Response $response): AuthResult
+    {
+        $username = null;
+        $password = null;
+
+        $authenticationMethod = $this->obtainAuthenticationMethodFromRequest($request);
+
+        if (!$authenticationMethod) {
+            [$username, $password] = $this->obtainUsernamePasswordFromRequest($request);
+        }
+
+        $authenticationData = AuthenticationData::create()
+            ->withUsername($username)
+            ->withPassword($password)
+            ->withMethod($authenticationMethod);
+
+        $hasAuthData = $username || $authenticationMethod;
+
+        if (!$hasAuthData) {
+            $password = $this->obtainTokenFromCookies($request);
+
+            if ($password) {
+                $authenticationData = AuthenticationData::create()
+                    ->withPassword($password)
+                    ->withByTokenOnly(true);
+
+                $hasAuthData = true;
+            }
+        }
+
+        if (!$this->authRequired && !$this->isEntryPoint && $hasAuthData) {
+            $authResult = $this->processAuthNotRequired(
+                $authenticationData,
+                $request,
+                $response
+            );
+
+            if ($authResult) {
+                return $authResult;
+            }
+        }
+
+        if (!$this->authRequired) {
+            return AuthResult::createResolvedUseNoAuth();
+        }
+
+        if ($hasAuthData) {
+            return $this->processWithAuthData($authenticationData, $request, $response);
+        }
+
+        $showDialog =
+            ($this->isEntryPoint || !$this->isXMLHttpRequest($request)) &&
+            !$request->getHeader('Referer') &&
+            $request->getMethod() !== Method::POST;
+
+        $this->handleUnauthorized($response, null, $showDialog);
+
+        return AuthResult::createNotResolved();
+    }
+
+    /**
+     * @throws Exception
+     */
+    private function processAuthNotRequired(
+        AuthenticationData $data,
+        Request $request,
+        Response $response
+    ): ?AuthResult {
+
+        try {
+            $result = $this->authentication->login($data, $request, $response);
+        } catch (Exception $e) {
+            $this->handleException($response, $e);
+
+            return AuthResult::createNotResolved();
+        }
+
+        if (!$result->isFail()) {
+            return AuthResult::createResolved();
+        }
+
+        return null;
+    }
+
+    /**
+     * @throws Exception
+     */
+    private function processWithAuthData(
+        AuthenticationData $data,
+        Request $request,
+        Response $response
+    ): AuthResult {
+
+        try {
+            $result = $this->authentication->login($data, $request, $response);
+        } catch (Exception $e) {
+            $this->handleException($response, $e);
+
+            return AuthResult::createNotResolved();
+        }
+
+        if ($result->isSuccess()) {
+            return AuthResult::createResolved();
+        }
+
+        if ($result->isFail()) {
+            $showDialog =
+                $this->isEntryPoint &&
+                !$request->getHeader('Referer') &&
+                $request->getMethod() !== Method::POST;
+
+            $this->handleUnauthorized($response, $result, $showDialog);
+        }
+
+        if ($result->isSecondStepRequired()) {
+            $this->handleSecondStepRequired($response, $result);
+        }
+
+        return AuthResult::createNotResolved();
+    }
+
+    /**
+     * @return array{string, string}
+     * @throws BadRequest
+     */
+    private function decodeAuthorizationString(string $string): array
+    {
+        /** @var string $stringDecoded */
+        $stringDecoded = base64_decode($string);
+
+        if (!str_contains($stringDecoded, ':')) {
+            throw new BadRequest("Auth: Bad authorization string provided.");
+        }
+
+        [$username, $password] = explode(':', $stringDecoded, 2);
+
+        $username = trim($username);
+        $password = trim($password);
+
+        return [$username, $password];
+    }
+
+    private function handleSecondStepRequired(Response $response, Result $result): void
+    {
+        $response->setStatus(401);
+        $response->setHeader('X-Status-Reason', 'second-step-required');
+
+        $bodyData = [
+            'status' => $result->getStatus(),
+            'message' => $result->getMessage(),
+            'view' => $result->getView(),
+            'token' => $result->getToken(),
+            'data' => $result->getData(),
+        ];
+
+        $response->writeBody(Json::encode($bodyData));
+    }
+
+    /**
+     * @throws Exception
+     */
+    private function handleException(Response $response, Exception $e): void
+    {
+        if (
+            $e instanceof BadRequest ||
+            $e instanceof ServiceUnavailable ||
+            $e instanceof Forbidden
+        ) {
+            $reason = $e->getMessage();
+
+            if ($reason) {
+                $response->setHeader('X-Status-Reason', $e->getMessage());
+            }
+
+            $response->setStatus($e->getCode());
+
+            if ($e->getBody()) {
+                $response->writeBody($e->getBody());
+            }
+
+            if ($e->getMessage()) {
+                $this->log->notice("Auth exception: {message}", ['message' => $e->getMessage()]);
+            }
+
+            return;
+        }
+
+        throw $e;
+    }
+
+    private function handleUnauthorized(Response $response, ?Result $result, bool $showDialog): void
+    {
+        if ($showDialog) {
+            $response->setHeader('WWW-Authenticate', 'Basic realm=""');
+        }
+
+        if ($result && $result->getFailReason() === Result\FailReason::ERROR) {
+            $response = $response->setHeader('X-Status-Reason', 'error');
+        }
+
+        $response->setStatus(401);
+    }
+
+    private function isXMLHttpRequest(Request $request): bool
+    {
+        if (strtolower($request->getHeader('X-Requested-With') ?? '') == 'xmlhttprequest') {
+            return true;
+        }
+
+        return false;
+    }
+
+    private function obtainAuthenticationMethodFromRequest(Request $request): ?string
+    {
+        if ($request->hasHeader(HeaderKey::AUTHORIZATION)) {
+            return null;
+        }
+
+        $paramsList = array_values(array_filter(
+            $this->configDataProvider->getLoginMetadataParamsList(),
+            function ($params) use ($request): bool {
+                $header = $params->getCredentialsHeader();
+
+                if (!$header || !$params->isApi()) {
+                    return false;
+                }
+
+                return $request->hasHeader($header);
+            }
+        ));
+
+        if (count($paramsList)) {
+            return $paramsList[0]->getMethod();
+        }
+
+        return null;
+    }
+
+    /**
+     * @return array{?string, ?string}
+     * @throws BadRequest
+     */
+    private function obtainUsernamePasswordFromRequest(Request $request): array
+    {
+        if ($request->hasHeader(HeaderKey::AUTHORIZATION)) {
+            $headerValue = $request->getHeader(HeaderKey::AUTHORIZATION) ?? '';
+
+            return $this->decodeAuthorizationString($headerValue);
+        }
+
+        if (
+            $request->getServerParam('PHP_AUTH_USER') &&
+            $request->getServerParam('PHP_AUTH_PW')
+        ) {
+            $username = $request->getServerParam('PHP_AUTH_USER');
+            $password = $request->getServerParam('PHP_AUTH_PW');
+
+            if (is_string($username)) {
+                $username = trim($username);
+            }
+
+            if (is_string($password)) {
+                $password = trim($password);
+            }
+
+            return [$username, $password];
+        }
+
+        $cgiAuthString = $request->getHeader('Http-Espo-Cgi-Auth') ??
+            $request->getHeader('Redirect-Http-Espo-Cgi-Auth');
+
+        if ($cgiAuthString) {
+            [$username, $password] = $this->decodeAuthorizationString(substr($cgiAuthString, 6));
+
+            return [$username, $password];
+        }
+
+        return [null, null];
+    }
+
+    private function obtainTokenFromCookies(Request $request): ?string
+    {
+        return $request->getCookieParam('auth-token');
+    }
+}

application/Espo/Core/Api/AuthBuilder.php

@@ -0,0 +1,91 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Authentication\Authentication;
+use Espo\Core\Binding\BindingContainerBuilder;
+use Espo\Core\Binding\ContextualBinder;
+use Espo\Core\InjectableFactory;
+
+use RuntimeException;
+
+/**
+ * Builds Auth instance.
+ */
+class AuthBuilder
+{
+    private bool $authRequired = false;
+    private bool $isEntryPoint = false;
+    private ?Authentication $authentication = null;
+
+    public function __construct(private InjectableFactory $injectableFactory)
+    {}
+
+    public function setAuthentication(Authentication $authentication): self
+    {
+        $this->authentication = $authentication;
+
+        return $this;
+    }
+
+    public function setAuthRequired(bool $authRequired): self
+    {
+        $this->authRequired = $authRequired;
+
+        return $this;
+    }
+
+    public function forEntryPoint(): self
+    {
+        $this->isEntryPoint = true;
+
+        return $this;
+    }
+
+    public function build(): Auth
+    {
+        if (!$this->authentication) {
+            throw new RuntimeException("Authentication is not set.");
+        }
+
+        return $this->injectableFactory->createWithBinding(
+            Auth::class,
+            BindingContainerBuilder
+                ::create()
+                ->bindInstance(Authentication::class, $this->authentication)
+                ->inContext(Auth::class, function (ContextualBinder $binder) {
+                    $binder
+                        ->bindValue('$authRequired', $this->authRequired)
+                        ->bindValue('$isEntryPoint', $this->isEntryPoint);
+                })
+                ->build()
+        );
+    }
+}

application/Espo/Core/Api/AuthBuilderFactory.php

@@ -0,0 +1,43 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\InjectableFactory;
+
+class AuthBuilderFactory
+{
+    public function __construct(private InjectableFactory $injectableFactory)
+    {}
+
+    public function create(): AuthBuilder
+    {
+        return $this->injectableFactory->create(AuthBuilder::class);
+    }
+}

application/Espo/Core/Api/AuthResult.php

@@ -0,0 +1,79 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+/**
+ * An authentication result.
+ */
+class AuthResult
+{
+    private bool $isResolved = false;
+    private bool $isResolvedUseNoAuth = false;
+
+    public static function createResolved(): self
+    {
+        $obj = new self();
+
+        $obj->isResolved = true;
+
+        return $obj;
+    }
+
+    public static function createResolvedUseNoAuth(): self
+    {
+        $obj = new self();
+
+        $obj->isResolved = true;
+        $obj->isResolvedUseNoAuth = true;
+
+        return $obj;
+    }
+
+    public static function createNotResolved(): self
+    {
+        return new self();
+    }
+
+    /**
+     * Logged in successfully.
+     */
+    public function isResolved(): bool
+    {
+        return $this->isResolved;
+    }
+
+    /**
+     * No need to log in.
+     */
+    public function isResolvedUseNoAuth(): bool
+    {
+        return $this->isResolvedUseNoAuth;
+    }
+}

application/Espo/Core/Api/ControllerActionHandler.php

@@ -0,0 +1,90 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\NotFound;
+use Espo\Core\Utils\Config;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+
+/**
+ * @internal
+ */
+class ControllerActionHandler implements RequestHandlerInterface
+{
+    public function __construct(
+        private string $controllerName,
+        private string $actionName,
+        private ProcessData $processData,
+        private ResponseWrapper $responseWrapped,
+        private ControllerActionProcessor $controllerActionProcessor,
+        private Config $config
+    ) {}
+
+    /**
+     * @throws NotFound
+     */
+    public function handle(ServerRequestInterface $request): ResponseInterface
+    {
+        $requestWrapped = new RequestWrapper(
+            $request,
+            $this->processData->getBasePath(),
+            $this->processData->getRouteParams()
+        );
+
+        $this->beforeProceed();
+
+        $responseWrapped = $this->controllerActionProcessor->process(
+            $this->controllerName,
+            $this->actionName,
+            $requestWrapped,
+            $this->responseWrapped
+        );
+
+        $this->afterProceed($responseWrapped);
+
+        return $responseWrapped->toPsr7();
+    }
+
+    private function beforeProceed(): void
+    {
+        $this->responseWrapped->setHeader('Content-Type', 'application/json');
+    }
+
+    private function afterProceed(Response $responseWrapped): void
+    {
+        $responseWrapped
+            ->setHeader('X-App-Timestamp', (string) ($this->config->get('appTimestamp') ?? '0'))
+            ->setHeader('Expires', '0')
+            ->setHeader('Last-Modified', gmdate('D, d M Y H:i:s') . ' GMT')
+            ->setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
+    }
+}

application/Espo/Core/Api/ControllerActionProcessor.php

@@ -0,0 +1,217 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\NotFound;
+use Espo\Core\Exceptions\NotFoundSilent;
+use Espo\Core\InjectableFactory;
+use Espo\Core\Utils\ClassFinder;
+use Espo\Core\Utils\Json;
+
+use ReflectionClass;
+use ReflectionNamedType;
+use stdClass;
+
+/**
+ * Creates controller instances and processes actions.
+ */
+class ControllerActionProcessor
+{
+    public function __construct(
+        private InjectableFactory $injectableFactory,
+        private ClassFinder $classFinder
+    ) {}
+
+    /**
+     * @throws NotFound
+     */
+    public function process(
+        string $controllerName,
+        string $actionName,
+        Request $request,
+        ResponseWrapper $response
+    ): ResponseWrapper {
+
+        $controller = $this->createController($controllerName);
+
+        $requestMethod = $request->getMethod();
+
+        if (
+            $actionName == 'index' &&
+            property_exists($controller, 'defaultAction')
+        ) {
+            $actionName = $controller::$defaultAction ?? 'index';
+        }
+
+        $actionMethodName = 'action' . ucfirst($actionName);
+
+        $fullActionMethodName = strtolower($requestMethod) . ucfirst($actionMethodName);
+
+        $primaryActionMethodName = method_exists($controller, $fullActionMethodName) ?
+            $fullActionMethodName :
+            $actionMethodName;
+
+        if (!method_exists($controller, $primaryActionMethodName)) {
+            throw new NotFoundSilent(
+                "Action $requestMethod '$actionName' does not exist in controller '$controllerName'.");
+        }
+
+        if ($this->useShortParamList($controller, $primaryActionMethodName)) {
+            $result = $controller->$primaryActionMethodName($request, $response) ?? null;
+
+            $this->handleResult($response, $result);
+
+            return $response;
+        }
+
+        // Below is a legacy way.
+
+        $data = $request->getBodyContents();
+
+        if ($data && $this->getRequestContentType($request) === 'application/json') {
+            $data = json_decode($data);
+        }
+
+        $params = $request->getRouteParams();
+
+        $beforeMethodName = 'before' . ucfirst($actionName);
+
+        if (method_exists($controller, $beforeMethodName)) {
+            $controller->$beforeMethodName($params, $data, $request, $response);
+        }
+
+        $result = $controller->$primaryActionMethodName($params, $data, $request, $response) ?? null;
+
+        $afterMethodName = 'after' . ucfirst($actionName);
+
+        if (method_exists($controller, $afterMethodName)) {
+            $controller->$afterMethodName($params, $data, $request, $response);
+        }
+
+        $this->handleResult($response, $result);
+
+        return $response;
+    }
+
+    /**
+     * @param mixed $result
+     */
+    private function handleResult(Response $response, $result): void
+    {
+        $responseContents = $result;
+
+        if (
+            is_int($result) ||
+            is_float($result) ||
+            is_array($result) ||
+            is_bool($result) ||
+            $result instanceof stdClass
+        ) {
+            $responseContents = Json::encode($result);
+        }
+
+        if (is_string($responseContents)) {
+            $response->writeBody($responseContents);
+        }
+    }
+
+    private function useShortParamList(object $controller, string $methodName): bool
+    {
+        $class = new ReflectionClass($controller);
+
+        $method = $class->getMethod($methodName);
+        $params = $method->getParameters();
+
+        if (count($params) === 0) {
+            return false;
+        }
+
+        $type = $params[0]->getType();
+
+        if (
+            !$type instanceof ReflectionNamedType ||
+            $type->isBuiltin()
+        ) {
+            return false;
+        }
+
+        /** @var class-string $className */
+        $className = $type->getName();
+
+        $firstParamClass = new ReflectionClass($className);
+
+        if (
+            $firstParamClass->getName() === Request::class ||
+            $firstParamClass->isSubclassOf(Request::class)
+        ) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * @return class-string
+     * @throws NotFound
+     */
+    private function getControllerClassName(string $name): string
+    {
+        $className = $this->classFinder->find('Controllers', $name);
+
+        if (!$className) {
+            throw new NotFound("Controller '$name' does not exist.");
+        }
+
+        if (!class_exists($className)) {
+            throw new NotFound("Class not found for controller '$name'.");
+        }
+
+        return $className;
+    }
+
+    /**
+     * @throws NotFound
+     */
+    private function createController(string $name): object
+    {
+        return $this->injectableFactory->createWith($this->getControllerClassName($name), [
+            'name' => $name,
+        ]);
+    }
+
+    private function getRequestContentType(Request $request): ?string
+    {
+        if ($request instanceof RequestWrapper) {
+            return $request->getContentType();
+        }
+
+        return null;
+    }
+}

application/Espo/Core/Api/ErrorOutput.php

@@ -0,0 +1,278 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Exceptions\Conflict;
+use Espo\Core\Exceptions\Error;
+use Espo\Core\Exceptions\Forbidden;
+use Espo\Core\Exceptions\HasBody;
+use Espo\Core\Exceptions\HasLogLevel;
+use Espo\Core\Exceptions\HasLogMessage;
+use Espo\Core\Exceptions\NotFound;
+use Espo\Core\Utils\Log;
+
+use LogicException;
+use Psr\Log\LogLevel;
+use RuntimeException;
+use Throwable;
+
+/**
+ * Processes an error output. If an exception occurred, it will be passed to here.
+ */
+class ErrorOutput
+{
+    /** @var array<int, string> */
+    private $errorDescriptions = [
+        400 => 'Bad Request',
+        401 => 'Unauthorized',
+        403 => 'Forbidden',
+        404 => 'Page Not Found',
+        409 => 'Conflict',
+        500 => 'Internal Server Error',
+        503 => 'Service Unavailable',
+    ];
+
+    /** @var int[] */
+    private $allowedStatusCodeList = [
+        200,
+        201,
+        400,
+        401,
+        403,
+        404,
+        409,
+        500,
+        503,
+    ];
+
+    /** @var class-string<Throwable>[] */
+    private array $printStatusReasonExceptionClassNameList = [
+        Error::class,
+        Forbidden::class,
+        Conflict::class,
+        BadRequest::class,
+        NotFound::class,
+    ];
+
+    public function __construct(private Log $log)
+    {}
+
+    public function process(
+        Request $request,
+        Response $response,
+        Throwable $exception,
+        ?string $route = null
+    ): void {
+
+        $this->processInternal($request, $response, $exception, $route);
+    }
+
+    public function processWithBodyPrinting(
+        Request $request,
+        Response $response,
+        Throwable $exception,
+        ?string $route = null
+    ): void {
+
+        $this->processInternal($request, $response, $exception, $route, true);
+    }
+
+    private function processInternal(
+        Request $request,
+        Response $response,
+        Throwable $exception,
+        ?string $route = null,
+        bool $toPrintBody = false
+    ): void {
+
+        $message = $exception->getMessage();
+
+        if ($exception->getPrevious() && $exception->getPrevious()->getMessage()) {
+            $message .= " " . $exception->getPrevious()->getMessage();
+        }
+
+        $statusCode = $exception->getCode();
+
+        if ($exception instanceof HasLogMessage) {
+            $message = $exception->getLogMessage();
+        }
+
+        if ($route) {
+            $this->processRoute($route, $request, $exception);
+        }
+
+        $level = $this->getLevel($exception);
+
+        $this->log->log($level, $message, [
+            'exception' => $exception,
+            'request' => $request,
+        ]);
+
+        if (!in_array($statusCode, $this->allowedStatusCodeList)) {
+            $statusCode = 500;
+        }
+
+        $response->setStatus($statusCode);
+
+        if ($this->toPrintExceptionStatusReason($exception)) {
+            $response->setHeader('X-Status-Reason', $this->stripInvalidCharactersFromHeaderValue($message));
+        }
+
+        if ($exception instanceof HasBody && $this->exceptionHasBody($exception)) {
+            $response->writeBody($exception->getBody() ?? '');
+
+            $toPrintBody = false;
+        }
+
+        if ($toPrintBody) {
+            $codeDescription = $this->getCodeDescription($statusCode);
+
+            $statusText = isset($codeDescription) ?
+                $statusCode . ' '. $codeDescription :
+                'HTTP ' . $statusCode;
+
+            if ($message) {
+                $message = htmlspecialchars($message);
+            }
+
+            $response->writeBody(self::generateErrorBody($statusText, $message));
+        }
+    }
+
+    private function exceptionHasBody(Throwable $exception): bool
+    {
+        if (!$exception instanceof HasBody) {
+            return false;
+        }
+
+        $exceptionBody = $exception->getBody();
+
+        return $exceptionBody !== null;
+    }
+
+    private function getCodeDescription(int $statusCode): ?string
+    {
+        if (isset($this->errorDescriptions[$statusCode])) {
+            return $this->errorDescriptions[$statusCode];
+        }
+
+        return null;
+    }
+
+    private function clearPasswords(string $string): string
+    {
+        return preg_replace('/"(.*password.*)":".*"/i', '"$1":"*****"', $string) ?? $string;
+    }
+
+    private static function generateErrorBody(string $header, string $text): string
+    {
+        $body = "<h1>" . $header . "</h1>";
+        $body .= $text;
+
+        return $body;
+    }
+
+    private function stripInvalidCharactersFromHeaderValue(string $value): string
+    {
+        $pattern = "/[^ \t\x21-\x7E\x80-\xFF]/";
+
+        /** @var string */
+        return preg_replace($pattern, ' ', $value);
+    }
+
+    private function processRoute(string $route, Request $request, Throwable $exception): void
+    {
+        $requestBodyString = $this->clearPasswords($request->getBodyContents() ?? '');
+
+        $message = $exception->getMessage();
+
+        if ($exception->getPrevious() && $exception->getPrevious()->getMessage()) {
+            $message .= " " . $exception->getPrevious()->getMessage();
+        }
+
+        $statusCode = $exception->getCode();
+
+        $routeParams = $request->getRouteParams();
+
+        $logMessage = "API ($statusCode) ";
+
+        $logMessageItemList = [];
+
+        if ($message) {
+            $logMessageItemList[] = $message;
+        }
+
+        $logMessageItemList[] = $request->getMethod() . ' ' . $request->getResourcePath();
+
+        if ($requestBodyString) {
+            $logMessageItemList[] = "Input data: " . $requestBodyString;
+        }
+
+        $logMessageItemList[] = "Route pattern: " . $route;
+
+        if (!empty($routeParams)) {
+            $logMessageItemList[] = "Route params: " . print_r($routeParams, true);
+        }
+
+        $logMessage .= implode("; ", $logMessageItemList);
+
+        $this->log->debug($logMessage);
+    }
+
+    private function toPrintExceptionStatusReason(Throwable $exception): bool
+    {
+        foreach ($this->printStatusReasonExceptionClassNameList as $clasName) {
+
+            if ($exception instanceof ($clasName)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    private function getLevel(Throwable $exception): string
+    {
+        if ($exception instanceof HasLogLevel) {
+            return $exception->getLogLevel();
+        }
+
+        if ($exception instanceof LogicException) {
+            return LogLevel::ALERT;
+        }
+
+        if ($exception instanceof RuntimeException) {
+            return LogLevel::CRITICAL;
+        }
+
+        return LogLevel::ERROR;
+    }
+}

application/Espo/Core/Api/Method.php

@@ -0,0 +1,47 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+/**
+ * @since 9.2.0
+ */
+class Method
+{
+    public const HEAD = 'HEAD';
+    public const GET = 'GET';
+    public const POST = 'POST';
+    public const PUT = 'PUT';
+    public const PATCH = 'PATCH';
+    public const DELETE = 'DELETE';
+    public const PURGE = 'PURGE';
+    public const OPTIONS = 'OPTIONS';
+    public const TRACE = 'TRACE';
+    public const CONNECT = 'CONNECT';
+}

application/Espo/Core/Api/MiddlewareProvider.php

@@ -0,0 +1,128 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\InjectableFactory;
+use Espo\Core\Utils\Metadata;
+use Psr\Http\Server\MiddlewareInterface;
+
+/**
+ * @internal
+ */
+class MiddlewareProvider
+{
+    public function __construct(
+        private Metadata $metadata,
+        private InjectableFactory $injectableFactory
+    ) {}
+
+    /**
+     * @return MiddlewareInterface[]
+     */
+    public function getGlobalMiddlewareList(): array
+    {
+        return $this->createFromClassNameList($this->getGlobalMiddlewareClassNameList());
+    }
+
+    /**
+     * @return MiddlewareInterface[]
+     */
+    public function getRouteMiddlewareList(Route $route): array
+    {
+        $key = strtolower($route->getMethod()) . '_' . $route->getRoute();
+
+        /** @var class-string<MiddlewareInterface>[] $classNameList */
+        $classNameList = $this->metadata->get(['app', 'api', 'routeMiddlewareClassNameListMap', $key]) ?? [];
+
+        return $this->createFromClassNameList($classNameList);
+    }
+
+    /**
+     * @return MiddlewareInterface[]
+     */
+    public function getActionMiddlewareList(Route $route): array
+    {
+        $key = strtolower($route->getMethod()) . '_' . $route->getRoute();
+
+        /** @var class-string<MiddlewareInterface>[] $classNameList */
+        $classNameList = $this->metadata->get(['app', 'api', 'actionMiddlewareClassNameListMap', $key]) ?? [];
+
+        return $this->createFromClassNameList($classNameList);
+    }
+
+    /**
+     * @return MiddlewareInterface[]
+     */
+    public function getControllerMiddlewareList(string $controller): array
+    {
+        /** @var class-string<MiddlewareInterface>[] $classNameList */
+        $classNameList = $this->metadata
+            ->get(['app', 'api', 'controllerMiddlewareClassNameListMap', $controller]) ?? [];
+
+        return $this->createFromClassNameList($classNameList);
+    }
+
+    /**
+     * @return MiddlewareInterface[]
+     */
+    public function getControllerActionMiddlewareList(string $method, string $controller, string $action): array
+    {
+        $key = $controller . '_' . strtolower($method) . '_' . $action;
+
+        /** @var class-string<MiddlewareInterface>[] $classNameList */
+        $classNameList = $this->metadata
+            ->get(['app', 'api', 'controllerActionMiddlewareClassNameListMap', $key]) ?? [];
+
+        return $this->createFromClassNameList($classNameList);
+    }
+
+    /**
+     * @return class-string<MiddlewareInterface>[]
+     */
+    private function getGlobalMiddlewareClassNameList(): array
+    {
+        return $this->metadata->get(['app', 'api', 'globalMiddlewareClassNameList']) ?? [];
+    }
+
+    /**
+     * @param class-string<MiddlewareInterface>[] $classNameList
+     * @return MiddlewareInterface[]
+     */
+    private function createFromClassNameList(array $classNameList): array
+    {
+        $list = [];
+
+        foreach ($classNameList as $className) {
+            $list[] = $this->injectableFactory->create($className);
+        }
+
+        return $list;
+    }
+}

application/Espo/Core/Api/ProcessData.php

@@ -0,0 +1,66 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+class ProcessData
+{
+    /**
+     * @param array<string, string> $routeParams
+     */
+    public function __construct(
+        private Route $route,
+        private string $basePath,
+        private array $routeParams
+    ) {}
+
+    /**
+     * @return Route
+     */
+    public function getRoute(): Route
+    {
+        return $this->route;
+    }
+
+    /**
+     * @return string
+     */
+    public function getBasePath(): string
+    {
+        return $this->basePath;
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    public function getRouteParams(): array
+    {
+        return $this->routeParams;
+    }
+}

application/Espo/Core/Api/Request.php

@@ -0,0 +1,128 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Psr\Http\Message\UriInterface;
+
+use stdClass;
+
+/**
+ * Representation of an HTTP request.
+ */
+interface Request
+{
+    /**
+     * Whether a query parameter is set.
+     */
+    public function hasQueryParam(string $name): bool;
+
+    /**
+     * Get a query parameter.
+     */
+    public function getQueryParam(string $name): ?string;
+
+    /**
+     * Get all query parameters.
+     *
+     * @return array<string, string|array<scalar, mixed>>
+     */
+    public function getQueryParams(): array;
+
+    /**
+     * Whether a route parameter is set.
+     */
+    public function hasRouteParam(string $name): bool;
+
+    /**
+     * Get a route parameter.
+     */
+    public function getRouteParam(string $name): ?string;
+
+    /**
+     * Get all route parameters.
+     *
+     * @return array<string, string>
+     */
+    public function getRouteParams(): array;
+
+    /**
+     * Get a header value. Multiple values will be concatenated with a comma.
+     */
+    public function getHeader(string $name): ?string;
+
+    /**
+     * Whether a header is set.
+     */
+    public function hasHeader(string $name): bool;
+
+    /**
+     * Get a header values as an array.
+     *
+     * @return string[]
+     */
+    public function getHeaderAsArray(string $name): array;
+
+    /**
+     * Get a request method.
+     */
+    public function getMethod(): string;
+
+    /**
+     * Get Uri.
+     */
+    public function getUri(): UriInterface;
+
+    /**
+     * Get a relative path of a request (w/o base path).
+     */
+    public function getResourcePath(): string;
+
+    /**
+     * Get body contents.
+     */
+    public function getBodyContents(): ?string;
+
+    /**
+     * Get a parsed body. If JSON array is passed, then will be converted to `{"list": ARRAY}`.
+     */
+    public function getParsedBody(): stdClass;
+
+    /**
+     * Get a cookie param value.
+     */
+    public function getCookieParam(string $name): ?string;
+
+    /**
+     * Get a server param value.
+     *
+     * @return mixed
+     */
+    public function getServerParam(string $name);
+}

application/Espo/Core/Api/RequestNull.php

@@ -0,0 +1,133 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Api\Request as ApiRequest;
+
+use Psr\Http\Message\UriInterface;
+use Slim\Psr7\Factory\UriFactory;
+
+use stdClass;
+
+/**
+ * An empty stub for Request.
+ */
+class RequestNull implements ApiRequest
+{
+    public function hasQueryParam(string $name): bool
+    {
+        return false;
+    }
+
+    /**
+     * @return null
+     * @noinspection PhpDocSignatureInspection
+     */
+    public function getQueryParam(string $name): ?string
+    {
+        return null;
+    }
+
+    public function getQueryParams(): array
+    {
+        return [];
+    }
+
+    public function hasRouteParam(string $name): bool
+    {
+        return false;
+    }
+
+    public function getRouteParam(string $name): ?string
+    {
+        return null;
+    }
+
+    public function getRouteParams(): array
+    {
+        return [];
+    }
+
+    public function getHeader(string $name): ?string
+    {
+        return null;
+    }
+
+    public function hasHeader(string $name): bool
+    {
+        return false;
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getHeaderAsArray(string $name): array
+    {
+        return [];
+    }
+
+    public function getMethod(): string
+    {
+        return '';
+    }
+
+    public function getUri(): UriInterface
+    {
+        return (new UriFactory())->createUri();
+    }
+
+    public function getResourcePath(): string
+    {
+        return '';
+    }
+
+    public function getBodyContents(): ?string
+    {
+        return null;
+    }
+
+    public function getParsedBody(): stdClass
+    {
+        return (object) [];
+    }
+
+    public function getCookieParam(string $name): ?string
+    {
+        return null;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getServerParam(string $name)
+    {
+        return null;
+    }
+}

application/Espo/Core/Api/RequestWrapper.php

@@ -0,0 +1,292 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Utils\Json;
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Api\Request as ApiRequest;
+
+use Psr\Http\Message\ServerRequestInterface as Psr7Request;
+use Psr\Http\Message\UriInterface;
+
+use stdClass;
+
+/**
+ * Adapter for PSR-7 request interface.
+ */
+class RequestWrapper implements ApiRequest
+{
+    private ?stdClass $parsedBody = null;
+
+    /**
+     * @param array<string, string> $routeParams
+     */
+    public function __construct(
+        private Psr7Request $psr7Request,
+        private string $basePath = '',
+        private array $routeParams = []
+    ) {}
+
+    /**
+     * Get a route or query parameter. Route params have a higher priority.
+     *
+     * @todo Don't support NULL $name.
+     * @deprecated As of v6.0. Use getQueryParam & getRouteParam. Left for backward compatibility.
+     *
+     * @return mixed
+     */
+    public function get(?string $name = null)
+    {
+        if (is_null($name)) {
+            return array_merge(
+                $this->getQueryParams(),
+                $this->routeParams
+            );
+        }
+
+        if ($this->hasRouteParam($name)) {
+            return $this->getRouteParam($name);
+        }
+
+        return $this->psr7Request->getQueryParams()[$name] ?? null;
+    }
+
+    public function hasRouteParam(string $name): bool
+    {
+        return array_key_exists($name, $this->routeParams);
+    }
+
+    public function getRouteParam(string $name): ?string
+    {
+        return $this->routeParams[$name] ?? null;
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    public function getRouteParams(): array
+    {
+        return $this->routeParams;
+    }
+
+    public function hasQueryParam(string $name): bool
+    {
+        return array_key_exists($name, $this->psr7Request->getQueryParams());
+    }
+
+    public function getQueryParam(string $name): ?string
+    {
+        $value = $this->psr7Request->getQueryParams()[$name] ?? null;
+
+        if (!is_string($value)) {
+            return null;
+        }
+
+        return $value;
+    }
+
+    public function getQueryParams(): array
+    {
+        return $this->psr7Request->getQueryParams();
+    }
+
+    public function getHeader(string $name): ?string
+    {
+        if (!$this->psr7Request->hasHeader($name)) {
+            return null;
+        }
+
+        return $this->psr7Request->getHeaderLine($name);
+    }
+
+    public function hasHeader(string $name): bool
+    {
+        return $this->psr7Request->hasHeader($name);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getHeaderAsArray(string $name): array
+    {
+        if (!$this->psr7Request->hasHeader($name)) {
+            return [];
+        }
+
+        return $this->psr7Request->getHeader($name);
+    }
+
+    public function getMethod(): string
+    {
+        return $this->psr7Request->getMethod();
+    }
+
+    public function getContentType(): ?string
+    {
+        if (!$this->hasHeader('Content-Type')) {
+            return null;
+        }
+
+        $contentType = explode(
+            ';',
+            $this->psr7Request->getHeader('Content-Type')[0]
+        )[0];
+
+        return strtolower($contentType);
+    }
+
+    public function getBodyContents(): ?string
+    {
+        $contents = $this->psr7Request->getBody()->getContents();
+
+        $this->psr7Request->getBody()->rewind();
+
+        return $contents;
+    }
+
+    /**
+     * @throws BadRequest
+     */
+    public function getParsedBody(): stdClass
+    {
+        if ($this->parsedBody === null) {
+            $this->initParsedBody();
+        }
+
+        if ($this->parsedBody === null) {
+            throw new BadRequest();
+        }
+
+        return Util::cloneObject($this->parsedBody);
+    }
+
+    /**
+     * @throws BadRequest
+     */
+    private function initParsedBody(): void
+    {
+        $contents = $this->getBodyContents();
+
+        $contentType = $this->getContentType();
+
+        if ($contentType === 'application/json' && $contents) {
+            $parsedBody = Json::decode($contents);
+
+            if (is_array($parsedBody)) {
+                $parsedBody = (object) [
+                    'list' => $parsedBody,
+                ];
+            }
+
+            if (!$parsedBody instanceof stdClass) {
+                throw new BadRequest("Body is not a JSON object.");
+            }
+
+            $this->parsedBody = $parsedBody;
+
+            return;
+        }
+
+        if (
+            in_array($contentType, ['application/x-www-form-urlencoded', 'multipart/form-data']) &&
+            $contents
+        ) {
+            $parsedBody = $this->psr7Request->getParsedBody();
+
+            if (is_array($parsedBody)) {
+                $this->parsedBody = (object) $parsedBody;
+
+                return;
+            }
+
+            if ($parsedBody instanceof stdClass) {
+                $this->parsedBody = $parsedBody;
+
+                return;
+            }
+        }
+
+        $this->parsedBody = (object) [];
+    }
+
+    public function getCookieParam(string $name): ?string
+    {
+        $params = $this->psr7Request->getCookieParams();
+
+        return $params[$name] ?? null;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getServerParam(string $name)
+    {
+        $params = $this->psr7Request->getServerParams();
+
+        return $params[$name] ?? null;
+    }
+
+    public function getUri(): UriInterface
+    {
+        return $this->psr7Request->getUri();
+    }
+
+    public function getResourcePath(): string
+    {
+        $path = $this->psr7Request->getUri()->getPath();
+
+        return substr($path, strlen($this->basePath));
+    }
+
+    public function isGet(): bool
+    {
+        return $this->getMethod() === Method::GET;
+    }
+
+    public function isPut(): bool
+    {
+        return $this->getMethod() === Method::PUT;
+    }
+
+    public function isPost(): bool
+    {
+        return $this->getMethod() === Method::POST;
+    }
+
+    public function isPatch(): bool
+    {
+        return $this->getMethod() === Method::PATCH;
+    }
+
+    public function isDelete(): bool
+    {
+        return $this->getMethod() === Method::DELETE;
+    }
+}

application/Espo/Core/Api/Response.php

@@ -0,0 +1,102 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Psr\Http\Message\StreamInterface;
+
+/**
+ * Representation of an HTTP response. An instance is mutable.
+ */
+interface Response
+{
+    /**
+     * Get a status code.
+     */
+    public function getStatusCode(): int;
+
+    /**
+     * Get a status reason phrase.
+     */
+    public function getReasonPhrase(): string;
+
+    /**
+     * Set a status code.
+     */
+    public function setStatus(int $code, ?string $reason = null): self;
+
+    /**
+     * Set a specific header.
+     */
+    public function setHeader(string $name, string $value): self;
+
+    /**
+     * Add a specific header.
+     */
+    public function addHeader(string $name, string $value): self;
+
+    /**
+     * Get a header value.
+     */
+    public function getHeader(string $name): ?string;
+
+    /**
+     * Whether a header is set.
+     */
+    public function hasHeader(string $name): bool;
+
+    /**
+     * Get all set header names.
+     *
+     * @return string[]
+     */
+    public function getHeaderNames(): array;
+
+    /**
+     * Get a header values as an array.
+     *
+     * @return string[]
+     */
+    public function getHeaderAsArray(string $name): array;
+
+    /**
+     * Write a body.
+     */
+    public function writeBody(string $string): self;
+
+    /**
+     * Set a body.
+     */
+    public function setBody(StreamInterface $body): self;
+
+    /**
+     * Get a body.
+     */
+    public function getBody(): StreamInterface;
+}

application/Espo/Core/Api/ResponseComposer.php

@@ -0,0 +1,59 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Slim\Psr7\Factory\ResponseFactory;
+use Espo\Core\Utils\Json;
+use stdClass;
+
+class ResponseComposer
+{
+    /**
+     * Compose a JSON response.
+     *
+     * @param array<string|int, mixed>|stdClass|scalar|null $data A data to encode.
+     */
+    public static function json(mixed $data): Response
+    {
+        return self::empty()
+            ->writeBody(Json::encode($data))
+            ->setHeader('Content-Type', 'application/json');
+    }
+
+    /**
+     * Compose an empty response.
+     */
+    public static function empty(): Response
+    {
+        $psr7Response = (new ResponseFactory())->createResponse();
+
+        return new ResponseWrapper($psr7Response);
+    }
+}

application/Espo/Core/Api/ResponseWrapper.php

@@ -0,0 +1,136 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Psr\Http\Message\ResponseInterface as Psr7Response;
+use Psr\Http\Message\StreamInterface;
+
+use Espo\Core\Api\Response as ApiResponse;
+
+/**
+ * Adapter for PSR-7 response interface.
+ */
+class ResponseWrapper implements ApiResponse
+{
+    public function __construct(private Psr7Response $psr7Response)
+    {
+        // Slim adds Authorization header. It's not needed.
+        $this->psr7Response = $this->psr7Response->withoutHeader('Authorization');
+    }
+
+    public function setStatus(int $code, ?string $reason = null): Response
+    {
+        $this->psr7Response = $this->psr7Response->withStatus($code, $reason ?? '');
+
+        return $this;
+    }
+
+    public function getStatusCode(): int
+    {
+        return $this->psr7Response->getStatusCode();
+    }
+
+    public function getReasonPhrase(): string
+    {
+        return $this->psr7Response->getReasonPhrase();
+    }
+
+    public function setHeader(string $name, string $value): Response
+    {
+        $this->psr7Response = $this->psr7Response->withHeader($name, $value);
+
+        return $this;
+    }
+
+    public function addHeader(string $name, string $value): Response
+    {
+        $this->psr7Response = $this->psr7Response->withAddedHeader($name, $value);
+
+        return $this;
+    }
+
+    public function getHeader(string $name): ?string
+    {
+        if (!$this->psr7Response->hasHeader($name)) {
+            return null;
+        }
+
+        return $this->psr7Response->getHeaderLine($name);
+    }
+
+    public function hasHeader(string $name): bool
+    {
+        return $this->psr7Response->hasHeader($name);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getHeaderAsArray(string $name): array
+    {
+        if (!$this->psr7Response->hasHeader($name)) {
+            return [];
+        }
+
+        return $this->psr7Response->getHeader($name);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getHeaderNames(): array
+    {
+        return array_keys($this->psr7Response->getHeaders());
+    }
+
+    public function writeBody(string $string): Response
+    {
+        $this->psr7Response->getBody()->write($string);
+
+        return $this;
+    }
+
+    public function setBody(StreamInterface $body): Response
+    {
+        $this->psr7Response = $this->psr7Response->withBody($body);
+
+        return $this;
+    }
+
+    public function getBody(): StreamInterface
+    {
+        return $this->psr7Response->getBody();
+    }
+
+    public function toPsr7(): Psr7Response
+    {
+        return $this->psr7Response;
+    }
+}

application/Espo/Core/Api/Route.php

@@ -0,0 +1,92 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+class Route
+{
+    private string $method;
+
+    /**
+     * @param array<string, string> $params
+     * @param ?class-string<Action> $actionClassName
+     */
+    public function __construct(
+        string $method,
+        private string $route,
+        private string $adjustedRoute,
+        private array $params,
+        private bool $noAuth,
+        private ?string $actionClassName
+    ) {
+        $this->method = strtoupper($method);
+    }
+
+    /**
+     * @return ?class-string<Action>
+     */
+    public function getActionClassName(): ?string
+    {
+        return $this->actionClassName;
+    }
+
+    public function getMethod(): string
+    {
+        return $this->method;
+    }
+
+    /**
+     * Get a route.
+     */
+    public function getRoute(): string
+    {
+        return $this->route;
+    }
+
+    /**
+     * Get an adjusted route for FastRoute.
+     */
+    public function getAdjustedRoute(): string
+    {
+        return $this->adjustedRoute;
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    public function getParams(): array
+    {
+        return $this->params;
+    }
+
+    public function noAuth(): bool
+    {
+        return $this->noAuth;
+    }
+}

application/Espo/Core/Api/Route/RouteParamsFetcher.php

@@ -0,0 +1,76 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api\Route;
+
+use Espo\Core\Api\Route;
+
+class RouteParamsFetcher
+{
+    /**
+     * @param array<string, mixed> $args
+     * @return array<string, mixed>
+     */
+    public function fetch(Route $item, array $args): array
+    {
+        $params = [];
+
+        $routeParams = $item->getParams();
+
+        $setKeyList = [];
+
+        foreach (array_keys($routeParams) as $key) {
+            $value = $routeParams[$key];
+
+            $paramName = $key;
+
+            if ($value[0] === ':') {
+                $realKey = substr($value, 1);
+
+                $params[$paramName] = $args[$realKey];
+
+                $setKeyList[] = $realKey;
+
+                continue;
+            }
+
+            $params[$paramName] = $value;
+        }
+
+        foreach ($args as $key => $value) {
+            if (in_array($key, $setKeyList)) {
+                continue;
+            }
+
+            $params[$key] = $value;
+        }
+
+        return $params;
+    }
+}

application/Espo/Core/Api/RouteProcessor.php

@@ -0,0 +1,275 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Exceptions\BadRequest;
+use Espo\Core\Authentication\AuthenticationFactory;
+use Espo\Core\InjectableFactory;
+use Espo\Core\Utils\Config;
+use Espo\Core\Utils\Log;
+use Espo\Core\ApplicationUser;
+
+use Psr\Http\Message\ResponseInterface as Psr7Response;
+use Psr\Http\Message\ServerRequestInterface as Psr7Request;
+
+use Slim\MiddlewareDispatcher;
+
+use Throwable;
+use LogicException;
+use Exception;
+
+/**
+ * Processes routes. Handles authentication. Obtains a controller name, action, body from a request.
+ * Then processes a controller action or an action.
+ *
+ * @internal
+ */
+class RouteProcessor
+{
+    public function __construct(
+        private AuthenticationFactory $authenticationFactory,
+        private AuthBuilderFactory $authBuilderFactory,
+        private ErrorOutput $errorOutput,
+        private Config $config,
+        private Log $log,
+        private ApplicationUser $applicationUser,
+        private ControllerActionProcessor $actionProcessor,
+        private MiddlewareProvider $middlewareProvider,
+        private InjectableFactory $injectableFactory
+    ) {}
+
+    public function process(
+        ProcessData $processData,
+        Psr7Request $request,
+        Psr7Response $response
+    ): Psr7Response {
+
+        $requestWrapped = new RequestWrapper($request, $processData->getBasePath(), $processData->getRouteParams());
+        $responseWrapped = new ResponseWrapper($response);
+
+        try {
+            return $this->processInternal(
+                $processData,
+                $request,
+                $requestWrapped,
+                $responseWrapped
+            );
+        } catch (Exception $exception) {
+            $this->handleException(
+                $exception,
+                $requestWrapped,
+                $responseWrapped,
+                $processData->getRoute()->getAdjustedRoute()
+            );
+
+            return $responseWrapped->toPsr7();
+        }
+    }
+
+    /**
+     * @throws BadRequest
+     */
+    private function processInternal(
+        ProcessData $processData,
+        Psr7Request $psrRequest,
+        RequestWrapper $request,
+        ResponseWrapper $response
+    ): Psr7Response {
+
+        $authRequired = !$processData->getRoute()->noAuth();
+
+        $apiAuth = $this->authBuilderFactory
+            ->create()
+            ->setAuthentication($this->authenticationFactory->create())
+            ->setAuthRequired($authRequired)
+            ->build();
+
+        $authResult = $apiAuth->process($request, $response);
+
+        if (!$authResult->isResolved()) {
+            return $response->toPsr7();
+        }
+
+        if ($authResult->isResolvedUseNoAuth()) {
+            $this->applicationUser->setupSystemUser();
+        }
+
+        ob_start();
+
+        $response = $this->processAfterAuth($processData, $psrRequest, $response);
+
+        ob_clean();
+
+        return $response;
+    }
+
+    /**
+     * @throws BadRequest
+     */
+    private function processAfterAuth(
+        ProcessData $processData,
+        Psr7Request $request,
+        ResponseWrapper $responseWrapped
+    ): Psr7Response {
+
+        $actionClassName = $processData->getRoute()->getActionClassName();
+
+        if ($actionClassName) {
+            return $this->processAction($actionClassName, $processData, $request, $responseWrapped);
+        }
+
+        return $this->processControllerAction($processData, $request, $responseWrapped);
+    }
+
+    /**
+     * @param class-string<Action> $actionClassName
+     */
+    private function processAction(
+        string $actionClassName,
+        ProcessData $processData,
+        Psr7Request $request,
+        ResponseWrapper $responseWrapped
+    ): Psr7Response {
+
+        /** @var Action $action */
+        $action = $this->injectableFactory->create($actionClassName);
+
+        $handler = new ActionHandler(
+            action: $action,
+            processData: $processData,
+            config: $this->config,
+        );
+
+        $dispatcher = new MiddlewareDispatcher($handler);
+
+        foreach ($this->middlewareProvider->getActionMiddlewareList($processData->getRoute()) as $middleware) {
+            $dispatcher->addMiddleware($middleware);
+        }
+
+        $response = $dispatcher->handle($request);
+
+        // Apply headers added by the authentication.
+        foreach ($responseWrapped->getHeaderNames() as $name) {
+            $response = $response->withHeader($name, $responseWrapped->getHeaderAsArray($name));
+        }
+
+        return $response;
+    }
+
+    /**
+     * @throws BadRequest
+     */
+    private function processControllerAction(
+        ProcessData $processData,
+        Psr7Request $request,
+        ResponseWrapper $responseWrapped
+    ): Psr7Response {
+
+        $controller = $this->getControllerName($processData);
+        $action = $processData->getRouteParams()['action'] ?? null;
+        $method = $request->getMethod();
+
+        if (!$action) {
+            $crudMethodActionMap = $this->config->get('crud') ?? [];
+            $action = $crudMethodActionMap[strtolower($method)] ?? null;
+
+            if (!$action) {
+                throw new BadRequest("No action for method `$method`.");
+            }
+        }
+
+        $handler = new ControllerActionHandler(
+            controllerName: $controller,
+            actionName: $action,
+            processData: $processData,
+            responseWrapped: $responseWrapped,
+            controllerActionProcessor: $this->actionProcessor,
+            config: $this->config,
+        );
+
+        $dispatcher = new MiddlewareDispatcher($handler);
+
+        $this->addControllerMiddlewares($dispatcher, $method, $controller, $action);
+
+        return $dispatcher->handle($request);
+    }
+
+    private function getControllerName(ProcessData $processData): string
+    {
+        $controllerName = $processData->getRouteParams()['controller'] ?? null;
+
+        if (!$controllerName) {
+            throw new LogicException("Route doesn't have specified controller.");
+        }
+
+        return ucfirst($controllerName);
+    }
+
+    private function handleException(
+        Exception $exception,
+        Request $request,
+        Response $response,
+        string $route
+    ): void {
+
+        try {
+            $this->errorOutput->process($request, $response, $exception, $route);
+        } catch (Throwable $exceptionAnother) {
+            $this->log->error($exceptionAnother->getMessage());
+
+            $response->setStatus(500);
+        }
+    }
+
+    /**
+     * @param MiddlewareDispatcher<null> $dispatcher
+     */
+    private function addControllerMiddlewares(
+        MiddlewareDispatcher $dispatcher,
+        string $method,
+        string $controller,
+        string $action
+    ): void {
+
+        $controllerActionMiddlewareList = $this->middlewareProvider
+            ->getControllerActionMiddlewareList($method, $controller, $action);
+
+        foreach ($controllerActionMiddlewareList as $middleware) {
+            $dispatcher->addMiddleware($middleware);
+        }
+
+        $controllerMiddlewareList = $this->middlewareProvider
+            ->getControllerMiddlewareList($controller);
+
+        foreach ($controllerMiddlewareList as $middleware) {
+            $dispatcher->addMiddleware($middleware);
+        }
+    }
+}

application/Espo/Core/Api/Starter.php

@@ -0,0 +1,154 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Api\Route\RouteParamsFetcher;
+use Espo\Core\Utils\Config\SystemConfig;
+use Espo\Core\Utils\Route as RouteUtil;
+use Espo\Core\Utils\Log;
+
+use Slim\App as SlimApp;
+use Slim\Exception\HttpBadRequestException;
+use Slim\Factory\AppFactory as SlimAppFactory;
+
+use Psr\Container\ContainerInterface;
+use Psr\Http\Message\ResponseInterface as Psr7Response;
+use Psr\Http\Message\ServerRequestInterface as Psr7Request;
+
+/**
+ * API request processing entry point.
+ */
+class Starter
+{
+    private string $routeCacheFile = 'data/cache/application/slim-routes.php';
+
+    public function __construct(
+        private RouteProcessor $routeProcessor,
+        private RouteUtil $routeUtil,
+        private RouteParamsFetcher $routeParamsFetcher,
+        private MiddlewareProvider $middlewareProvider,
+        private Log $log,
+        private SystemConfig $systemConfig,
+        ?string $routeCacheFile = null
+    ) {
+        $this->routeCacheFile = $routeCacheFile ?? $this->routeCacheFile;
+    }
+
+    public function start(): void
+    {
+        $slim = SlimAppFactory::create();
+
+        if (RouteUtil::isBadUri()) {
+            $this->processError($slim);
+
+            return;
+        }
+
+        if ($this->systemConfig->useCache()) {
+            $slim->getRouteCollector()->setCacheFile($this->routeCacheFile);
+        }
+
+        $slim->setBasePath(RouteUtil::detectBasePath());
+        $this->addGlobalMiddlewares($slim);
+        $slim->addRoutingMiddleware();
+        $this->addRoutes($slim);
+        $slim->addErrorMiddleware(false, true, true, $this->log);
+
+        $slim->run();
+    }
+
+    /**
+     * @param SlimApp<ContainerInterface|null> $slim
+     */
+    private function addGlobalMiddlewares(SlimApp $slim): void
+    {
+        foreach ($this->middlewareProvider->getGlobalMiddlewareList() as $middleware) {
+            $slim->add($middleware);
+        }
+    }
+
+    /**
+     * @param SlimApp<ContainerInterface|null> $slim
+     */
+    private function addRoutes(SlimApp $slim): void
+    {
+        $routeList = $this->routeUtil->getFullList();
+
+        foreach ($routeList as $item) {
+            $this->addRoute($slim, $item);
+        }
+    }
+
+    /**
+     * @param SlimApp<ContainerInterface|null> $slim
+     */
+    private function addRoute(SlimApp $slim, Route $item): void
+    {
+        $slimRoute = $slim->map(
+            [$item->getMethod()],
+            $item->getAdjustedRoute(),
+            function (Psr7Request $request, Psr7Response $response, array $args) use ($slim, $item) {
+                $routeParams = $this->routeParamsFetcher->fetch($item, $args);
+
+                $processData = new ProcessData(
+                    route: $item,
+                    basePath: $slim->getBasePath(),
+                    routeParams: $routeParams,
+                );
+
+                return $this->routeProcessor->process($processData, $request, $response);
+            }
+        );
+
+        $middlewareList = $this->middlewareProvider->getRouteMiddlewareList($item);
+
+        foreach ($middlewareList as $middleware) {
+            $slimRoute->addMiddleware($middleware);
+        }
+    }
+
+    /**
+     * @param SlimApp<ContainerInterface|null> $slim
+     */
+    private function processError(SlimApp $slim): void
+    {
+        $slim->add(function (Psr7Request $request): Psr7Response {
+            throw new HttpBadRequestException($request, 'Malformed request path.');
+        });
+
+        $slim->addErrorMiddleware(
+            displayErrorDetails: false,
+            logErrors: false,
+            logErrorDetails: false,
+        );
+
+        $slim->run();
+    }
+}

application/Espo/Core/Api/Util.php

@@ -0,0 +1,85 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM – Open Source CRM application.
+ * Copyright (C) 2014-2025 EspoCRM, Inc.
+ * Website: https://www.espocrm.com
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU Affero General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU Affero General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Api;
+
+use Espo\Core\Utils\Config;
+use stdClass;
+
+class Util
+{
+    public function __construct(private Config $config) {}
+
+    public static function cloneObject(stdClass $source): stdClass
+    {
+        $cloned = (object) [];
+
+        foreach (get_object_vars($source) as $k => $v) {
+            $cloned->$k = self::cloneObjectItem($v);
+        }
+
+        return $cloned;
+    }
+
+    /**
+     * @param mixed $item
+     * @return mixed
+     */
+    private static function cloneObjectItem($item)
+    {
+        if (is_array($item)) {
+            $cloned = [];
+
+            foreach ($item as $v) {
+                $cloned[] = self::cloneObjectItem($v);
+            }
+
+            return $cloned;
+        }
+
+        if ($item instanceof stdClass) {
+            return self::cloneObject($item);
+        }
+
+        if (is_object($item)) {
+            return clone $item;
+        }
+
+        return $item;
+    }
+
+    public function obtainIpFromRequest(Request $request): ?string
+    {
+        // Do not add support of any more parameters here.
+
+        $param = $this->config->get('ipAddressServerParam') ?? 'REMOTE_ADDR';
+
+        return $request->getServerParam($param);
+    }
+}