# /api/v3/projects/{id}/categories
---
get:
  parameters:
  - description: ID of the project whose categories will be listed
    example: '1'
    in: path
    name: id
    required: true
    schema:
      type: integer
  responses:
    '200':
      content:
        application/hal+json:
          examples:
            response:
              value:
                _embedded:
                  elements:
                  - _links:
                      defaultAssignee:
                        href: "/api/v3/users/42"
                        title: John Sheppard
                      project:
                        href: "/api/v3/projects/11"
                        title: Example project
                      self:
                        href: "/api/v3/categories/10"
                        title: Category with assignee
                    _type: Category
                    id: 10
                    name: Foo
                  - _links:
                      project:
                        href: "/api/v3/projects/11"
                      self:
                        href: "/api/v3/categories/11"
                    _type: Category
                    id: 11
                    name: Bar
                _links:
                  self:
                    href: "/api/v3/projects/11/categories"
                _type: Collection
                count: 2
                total: 2
          schema:
            "$ref": "../components/schemas/categories_by_project_model.yml"
      description: OK
      headers: {}
    '404':
      content:
        application/hal+json:
          examples:
            response:
              value:
                _type: Error
                errorIdentifier: urn:openproject-org:api:v3:errors:NotFound
                message: The specified project does not exist.
      description: |-
        Returned if the project does not exist or the client does not have sufficient permissions
        to see it.

        **Required permission:** view project

        *Note: A client without sufficient permissions shall not be able to test for the existence of a project.
        That's why a 404 is returned here, even if a 403 might be more appropriate.*
      headers: {}
  tags:
  - Categories
  description: ''
  operationId: List_categories_of_a_project
  summary: List categories of a project