diff --git a/api/openapi.yml b/api/openapi.yml
new file mode 100644
index 0000000..5899a97
--- /dev/null
+++ b/api/openapi.yml
@@ -0,0 +1,266 @@
+openapi: 3.0.3
+info:
+  title: Appointment Booking API
+  description: API for managing appointments, treatments, clients, and specialists.
+  version: 1.0.0
+
+servers:
+  - url: http://localhost:8080
+    description: Local development server
+
+paths:
+  /treatments:
+    get:
+      summary: Get a list of available treatments
+      operationId: getTreatments
+      tags:
+        - Treatments
+      responses:
+        "200":
+          description: List of treatments
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Treatment"
+
+    post:
+      summary: Create a new treatment
+      operationId: createTreatment
+      tags:
+        - Treatments
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/TreatmentRequest"
+      responses:
+        "201":
+          description: Treatment successfully created
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Treatment"
+        "400":
+          description: Invalid request data
+        "403":
+          description: Only specialists can create treatments
+
+  /treatments/{treatmentId}:
+    get:
+      summary: Get treatment details (with specialist info)
+      operationId: getTreatmentDetails
+      tags:
+        - Treatments
+      parameters:
+        - name: treatmentId
+          in: path
+          required: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: Treatment details including assigned specialist
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/TreatmentDetails"
+        "404":
+          description: Treatment not found
+
+  /appointments:
+    get:
+      summary: Get all appointments with filtering options
+      operationId: getAppointments
+      tags:
+        - Appointments
+      parameters:
+        - name: clientId
+          in: query
+          schema:
+            type: string
+        - name: specialistId
+          in: query
+          schema:
+            type: string
+        - name: status
+          in: query
+          schema:
+            type: string
+            enum: [SCHEDULED, CANCELLED, COMPLETED]
+      responses:
+        "200":
+          description: List of appointments
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/Appointment"
+
+    post:
+      summary: Schedule an appointment
+      operationId: createAppointment
+      tags:
+        - Appointments
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/AppointmentRequest"
+      responses:
+        "201":
+          description: Appointment successfully created
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Appointment"
+        "400":
+          description: Invalid request data
+        "409":
+          description: Appointment slot conflict
+
+  /appointments/{appointmentId}:
+    patch:
+      summary: Update appointment status
+      operationId: updateAppointmentStatus
+      tags:
+        - Appointments
+      parameters:
+        - name: appointmentId
+          in: path
+          required: true
+          schema:
+            type: string
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/AppointmentStatusUpdate"
+      responses:
+        "200":
+          description: Appointment status updated
+        "400":
+          description: Invalid status
+        "404":
+          description: Appointment not found
+
+  /availability:
+    get:
+      summary: Check appointment slot availability
+      operationId: checkAvailability
+      tags:
+        - Appointments
+      parameters:
+        - name: specialistId
+          in: query
+          required: true
+          schema:
+            type: string
+        - name: dateTime
+          in: query
+          required: true
+          schema:
+            type: string
+            format: date-time
+      responses:
+        "200":
+          description: Slot availability result
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  available:
+                    type: boolean
+
+components:
+  schemas:
+    Treatment:
+      type: object
+      properties:
+        id:
+          type: string
+          format: uuid
+        name:
+          type: string
+        duration:
+          type: integer
+          description: Duration of the treatment in minutes
+        specialistId:
+          type: string
+          format: uuid
+
+    TreatmentRequest:
+      type: object
+      properties:
+        name:
+          type: string
+        duration:
+          type: integer
+        specialistId:
+          type: string
+          format: uuid
+
+    TreatmentDetails:
+      allOf:
+        - $ref: "#/components/schemas/Treatment"
+        - type: object
+          properties:
+            specialist:
+              type: object
+              properties:
+                id:
+                  type: string
+                  format: uuid
+                name:
+                  type: string
+
+    AppointmentRequest:
+      type: object
+      required:
+        - clientId
+        - treatmentId
+        - dateTime
+      properties:
+        clientId:
+          type: string
+          format: uuid
+        treatmentId:
+          type: string
+          format: uuid
+        dateTime:
+          type: string
+          format: date-time
+
+    Appointment:
+      type: object
+      properties:
+        id:
+          type: string
+          format: uuid
+        clientId:
+          type: string
+          format: uuid
+        treatmentId:
+          type: string
+          format: uuid
+        dateTime:
+          type: string
+          format: date-time
+        status:
+          type: string
+          enum: [SCHEDULED, CANCELLED, COMPLETED]
+
+    AppointmentStatusUpdate:
+      type: object
+      required:
+        - status
+      properties:
+        status:
+          type: string
+          enum: [CANCELLED, COMPLETED]
diff --git a/pom.xml b/pom.xml
index fa69e55..cff0385 100644
--- a/pom.xml
+++ b/pom.xml
@@ -76,6 +76,25 @@
 			<artifactId>spring-security-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+
+		<!-- Dependencies required for OpenAPI code generation -->
+		<dependency>
+			<groupId>io.swagger.core.v3</groupId>
+			<artifactId>swagger-annotations</artifactId>
+			<version>2.2.28</version>
+		</dependency>
+		<dependency>
+			<groupId>org.openapitools</groupId>
+			<artifactId>jackson-databind-nullable</artifactId>
+			<version>0.2.6</version>
+		</dependency>
+
+		<!-- Dependencies for OpenAPI documentation and Swagger UI -->
+		<dependency>
+			<groupId>org.springdoc</groupId>
+			<artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
+			<version>2.8.5</version>
+		</dependency>
 	</dependencies>
 
 	<build>
@@ -135,10 +154,50 @@
 					</execution>
 				</executions>
 				<configuration>
-					<reportName>Test Report</reportName>
 					<aggregate>true</aggregate>
 				</configuration>
 			</plugin>
+			<plugin>
+				<groupId>org.openapitools</groupId>
+				<artifactId>openapi-generator-maven-plugin</artifactId>
+				<version>7.11.0</version>
+				<executions>
+					<execution>
+						<id>appointmentBooking</id>
+						<goals>
+							<goal>generate</goal>
+						</goals>
+						<configuration>
+							<inputSpec>${project.basedir}/api/openapi.yml</inputSpec>
+							<output>${project.build.directory}/generated-sources/openapi</output>
+							<cleanupOutput>true</cleanupOutput>
+							<generatorName>spring</generatorName>
+							<apiPackage>com.capgemini.training.appointment_booking_app.api</apiPackage>
+							<modelPackage>com.capgemini.training.appointment_booking_app.model</modelPackage>
+							<supportingFilesToGenerate>ApiUtil.java</supportingFilesToGenerate>
+							<generateApiTests>false</generateApiTests>
+							<generateModelTests>false</generateModelTests>
+							<configOptions>
+<!--								<delegatePattern>true</delegatePattern>-->
+								<useTags>true</useTags>
+								<library>spring-boot</library>
+								<useSpringBoot3>true</useSpringBoot3>
+								<useOptional>true</useOptional>
+								<useBeanValidation>true</useBeanValidation>
+								<dateLibrary>java-time</dateLibrary>
+								<generateBuilders>false</generateBuilders>
+								<generateConstructorWithAllArgs>true</generateConstructorWithAllArgs>
+								<additionalModelTypeAnnotations>
+									@lombok.Generated
+									@lombok.ToString
+								</additionalModelTypeAnnotations>
+								<documentationProvider>source</documentationProvider>
+								<annotationLibrary>swagger2</annotationLibrary>
+							</configOptions>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>