diff --git a/api/openapi.yaml b/api/openapi.yaml
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+openapi: "3.0.3"
+info:
+  title: "Backoffice API"
+  version: "0.1.0"
+  license:
+    name: Proprietary
+  contact:
+    name: Vojtěch Mareš
+    email: vojtech@mares.cz
+    url: https://www.mares.cz
+servers:
+  - url: http://localhost:8080/
+    description: Local development server
+  - url: https://staging.backoffice.vmdevel.cz/api
+    description: Backoffice staging server
+  - url: https://backoffice.mareshq.com/api
+    description: Backoffice production server
+paths:
+  /v0/trainings:
+    get:
+      summary: List all trainings
+      operationId: listTrainings
+      tags:
+        - Trainings
+      parameters:
+        - name: limit
+          in: query
+          description: Maximum number of trainings to return
+          required: false
+          schema:
+            type: integer
+            minimum: 1
+            maximum: 100
+            default: 10
+        - name: offsetID
+          in: query
+          description: ID of the training to start from
+          required: false
+          schema:
+            type: integer
+            minimum: 1
+      responses:
+        "200":
+          $ref: "#/components/responses/ListTrainingsResponse"
+        "500":
+          $ref: "#/components/responses/InternalError"
+    post:
+      summary: Create a new training
+      operationId: createTraining
+      tags:
+        - Trainings
+      requestBody:
+        $ref: "#/components/requestBodies/CreateTrainingRequest"
+      responses:
+        "201":
+          $ref: "#/components/responses/CreateTrainingResponse"
+        "400":
+          $ref: "#/components/responses/InvalidInputError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+  /v0/trainings/{trainingID}:
+    get:
+      summary: Get a training by ID
+      operationId: getTrainingByID
+      tags:
+        - Trainings
+      parameters:
+        - $ref: "#/components/parameters/TrainingID"
+      responses:
+        "200":
+          $ref: "#/components/responses/GetTrainingResponse"
+        "404":
+          $ref: "#/components/responses/NotFoundError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+  /v0/trainings/by-slug/{trainingSlug}:
+    get:
+      summary: Get a training by training slug
+      operationId: getTrainingBySlug
+      tags:
+        - Trainings
+      parameters:
+        - $ref: "#/components/parameters/TrainingSlug"
+      responses:
+        "200":
+          $ref: "#/components/responses/GetTrainingResponse"
+        "404":
+          $ref: "#/components/responses/NotFoundError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+  /v0/trainings/{trainingID}/publish:
+    put:
+      summary: Publish a training
+      operationId: publishTraining
+      tags:
+        - Trainings
+      parameters:
+        - $ref: "#/components/parameters/TrainingID"
+      responses:
+        "204":
+          description: Training published
+        "404":
+          $ref: "#/components/responses/NotFoundError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+  /v0/trainings/{trainingID}/unpublish:
+    put:
+      summary: Unpublish a training
+      operationId: unpublishTraining
+      tags:
+        - Trainings
+      parameters:
+        - $ref: "#/components/parameters/TrainingID"
+      responses:
+        "204":
+          description: Training unpublished
+        "404":
+          $ref: "#/components/responses/NotFoundError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+  /v0/trainings/{trainingID}/retire:
+    put:
+      summary: Retire a training
+      operationId: retireTraining
+      tags:
+        - Trainings
+      parameters:
+        - $ref: "#/components/parameters/TrainingID"
+      responses:
+        "204":
+          description: Training retired
+        "404":
+          $ref: "#/components/responses/NotFoundError"
+        "500":
+          $ref: "#/components/responses/InternalError"
+components:
+  parameters:
+    TrainingID:
+      name: trainingID
+      in: path
+      required: true
+      description: ID of the training
+      schema:
+        $ref: "#/components/schemas/TrainingID"
+    TrainingSlug:
+      name: trainingSlug
+      in: path
+      required: true
+      description: Slug of the training
+      schema:
+        type: string
+  # Models
+  schemas:
+    TrainingID:
+      type: integer
+      minimum: 1
+      x-go-type: training.ID
+      x-go-type-import:
+        path: gitlab.mareshq.com/hq/backoffice/backoffice-api/internal/training
+    NewTraining:
+      type: object
+      properties:
+        title:
+          type: string
+        slug:
+          type: string
+        description:
+          type: string
+        days:
+          type: integer
+          minimum: 1
+          maximum: 5
+          default: 1
+      required:
+        - title
+        - description
+        - days
+    Training:
+      allOf:
+        - $ref: "#/components/schemas/NewTraining"
+        - type: object
+          properties:
+            id:
+              $ref: "#/components/schemas/TrainingID"
+            published:
+              type: boolean
+            retired:
+              type: boolean
+          required:
+            - id
+            - slug
+            - published
+            - retired
+    ProblemDetails:
+      type: object
+      description: >
+        Schema that carries the details of an error in an HTTP response.
+        See https://datatracker.ietf.org/doc/html/rfc7807 for more information.
+      properties:
+        type:
+          type: string
+          description: A URI reference that identifies the problem type.
+        title:
+          type: string
+          description: A human-readable summary of the problem type.
+        status:
+          type: integer
+          description: The HTTP status code generated by the origin server for this occurrence of the problem.
+        detail:
+          type: string
+          description: A human-readable explanation specific to this occurrence of the problem.
+        instance:
+          type: string
+          description: A URI reference that identifies the specific occurrence of the problem.
+      required:
+        - type
+        - title
+        - status
+        - detail
+        - instance
+  # Response objects including content types
+  responses:
+    InvalidInputError:
+      description: Invalid input error
+      content:
+        application/problem+json:
+          schema:
+            $ref: "#/components/schemas/ProblemDetails"
+    InternalError:
+      description: Internal error
+      content:
+        application/problem+json:
+          schema:
+            $ref: "#/components/schemas/ProblemDetails"
+    NotFoundError:
+      description: Not found error
+      content:
+        application/problem+json:
+          schema:
+            $ref: "#/components/schemas/ProblemDetails"
+    ListTrainingsResponse:
+      description: Response containing a list of trainings
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              trainings:
+                type: array
+                description: List of trainings
+                items:
+                  $ref: "#/components/schemas/Training"
+    CreateTrainingResponse:
+      description: Response containing a newly created training
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Training"
+    GetTrainingResponse:
+      description: Response containing a single training
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/Training"
+  # Request body objects for creating or updating resources
+  requestBodies:
+    CreateTrainingRequest:
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              training:
+                $ref: "#/components/schemas/NewTraining"
+    UpdateTrainingRequest:
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              training:
+                $ref: "#/components/schemas/NewTraining"
diff --git a/api/v0/openapi.yaml b/api/v0/openapi.yaml
deleted file mode 100644
index e69de29..0000000