openapi: 3.1.2
info:
  description: "You're looking at the current **stable** documentation of the OpenProject APIv3. If you're interested in the current\ndevelopment version, please go to [github.com/opf](https://github.com/opf/openproject/tree/dev/docs/api/apiv3).\n\n## Introduction\n\nThe documentation for the APIv3 is written according to the [OpenAPI 3.1 Specification](https://swagger.io/specification/).\nYou can either view the static version of this documentation on the [website](https://www.openproject.org/docs/api/introduction/)\nor the interactive version, rendered with [OpenAPI Explorer](https://github.com/Rhosys/openapi-explorer/blob/main/README.md),\nin your OpenProject installation under `/api/docs`.\nIn the latter you can try out the various API endpoints directly interacting with our OpenProject data.\nMoreover you can access the specification source itself under `/api/v3/spec.json` and `/api/v3/spec.yml`\n(e.g. [here](https://community.openproject.org/api/v3/spec.yml)).\n\nThe APIv3 is a hypermedia REST API, a shorthand for \"Hypermedia As The Engine Of Application State\" (HATEOAS).\nThis means that each endpoint of this API will have links to other resources or actions defined in the resulting body.\n\nThese related resources and actions for any given resource will be context sensitive. For example, only actions that the\nauthenticated user can take are being rendered. This can be used to dynamically identify actions that the user might take for any\ngiven response.\n\nAs an example, if you fetch a work package through the [Work Package endpoint](https://www.openproject.org/docs/api/endpoints/work-packages/), the `update` link will only\nbe present when the user you authenticated has been granted a permission to update the work package in the assigned project.\n\n## HAL+JSON\n\nHAL is a simple format that gives a consistent and easy way to hyperlink between resources in your API.\nRead more in the following specification: [https://tools.ietf.org/html/draft-kelly-json-hal-08](https://tools.ietf.org/html/draft-kelly-json-hal-08)\n\n**OpenProject API implementation of HAL+JSON format** enriches JSON and introduces a few meta properties:\n\n- `_type` - specifies the type of the resource (e.g.: WorkPackage, Project)\n- `_links` - contains all related resource and action links available for the resource\n- `_embedded` - contains all embedded objects\n\nHAL does not guarantee that embedded resources are embedded in their full representation, they might as well be\npartially represented (e.g. some properties can be left out).\nHowever in this API you have the guarantee that whenever a resource is **embedded**, it is embedded in its **full representation**.\n\n## API response structure\n\nAll API responses contain a single HAL+JSON object, even collections of objects are technically represented by\na single HAL+JSON object that itself contains its members. More details on collections can be found\nin the [Collections Section](https://www.openproject.org/docs/api/collections/).\n\n## Authentication\n\nThe API supports the following authentication schemes:\n\n* Session-based authentication\n* API tokens\n    * passed as Bearer token\n    * passed via Basic auth\n* OAuth 2.0\n    * using built-in authorization server\n    * using an external authorization server (RFC 9068)\n\nDepending on the settings of the OpenProject instance many resources can be accessed without being authenticated.\nIn case the instance requires authentication on all requests the client will receive an **HTTP 401** status code\nin response to any request.\n\nOtherwise unauthenticated clients have all the permissions of the anonymous user.\n\n### Session-based authentication\n\nThis means you have to login to OpenProject via the Web-Interface to be authenticated in the API.\nThis method is well-suited for clients acting within the browser, like the Angular-Client built into OpenProject.\n\nIn this case, you always need to pass the HTTP header `X-Requested-With \"XMLHttpRequest\"` for authentication.\n\n### API token as bearer token\n\nUsers can authenticate towards the API v3 using an API token as a bearer token.\n\nFor example:\n\n```shell\nAPI_KEY=opapi-2519132cdf62dcf5a66fd96394672079f9e9cad1\ncurl -H \"Authorization: Bearer $API_KEY\" https://community.openproject.org/api/v3/users/42\n```\n\nUsers can generate API tokens on their account page.\n\n### API token through Basic Auth\n\nAPI tokens can also be used with basic auth, using the user name `apikey` (NOT your login) and the API token as the password.\n\nFor example:\n\n```shell\nAPI_KEY=opapi-2519132cdf62dcf5a66fd96394672079f9e9cad1\ncurl -u apikey:$API_KEY https://community.openproject.org/api/v3/users/42\n```\n\n### OAuth 2.0 authentication\n\nOpenProject allows authentication and authorization with OAuth2 with *Authorization code flow*, as well as *Client credentials* operation modes.\n\nTo get started, you first need to register an application in the OpenProject OAuth administration section of your installation.\nThis will save an entry for your application with a client unique identifier (`client_id`) and an accompanying secret key (`client_secret`).\n\nYou can then use one the following guides to perform the supported OAuth 2.0 flows:\n\n- [Authorization code flow](https://oauth.net/2/grant-types/authorization-code)\n\n- [Authorization code flow with PKCE](https://doorkeeper.gitbook.io/guides/ruby-on-rails/pkce-flow), recommended for clients unable to keep the client_secret confidential\n\n- [Client credentials](https://oauth.net/2/grant-types/client-credentials/) - Requires an application to be bound to an impersonating user for non-public access\n\n### OAuth 2.0 using an external authorization server\n\nThere is a possibility to use JSON Web Tokens (JWT) generated by an OIDC provider configured in OpenProject as a bearer token to do authenticated requests against the API.\nThe following requirements must be met:\n\n- OIDC provider must be configured in OpenProject with **jwks_uri**\n- JWT must be signed using RSA algorithm\n- JWT **iss** claim must be equal to OIDC provider **issuer**\n- JWT **aud** claim must contain the OpenProject **client ID** used at the OIDC provider\n- JWT **scope** claim must include a valid scope to access the desired API (e.g. `api_v3` for APIv3)\n- JWT must be actual (neither expired or too early to be used)\n- JWT must be passed in Authorization header like: `Authorization: Bearer {jwt}`\n- User from **sub** claim must be linked to OpenProject before (e.g. by logging in), otherwise it will be not authenticated\n\nIn more general terms, OpenProject should be compliant to [RFC 9068](https://www.rfc-editor.org/rfc/rfc9068) when validating access tokens.\n\n### Why not username and password?\n\nThe simplest way to do basic auth would be to use a user's username and password naturally.\nHowever, OpenProject already has supported API keys in the past for the API v2, though not through basic auth.\n\nUsing **username and password** directly would have some advantages:\n\n* It is intuitive for the user who then just has to provide those just as they would when logging into OpenProject.\n\n* No extra logic for token management necessary.\n\nOn the other hand using **API keys** has some advantages too, which is why we went for that:\n\n* If compromised while saved on an insecure client the user only has to regenerate the API key instead of changing their password, too.\n\n* They are naturally long and random which makes them invulnerable to dictionary attacks and harder to crack in general.\n\nMost importantly users may not actually have a password to begin with. Specifically when they have registered\nthrough an OpenID Connect provider.\n\n## Cross-Origin Resource Sharing (CORS)\n\nBy default, the OpenProject API is _not_ responding with any CORS headers.\nIf you want to allow cross-domain AJAX calls against your OpenProject instance, you need to enable CORS headers being returned.\n\nPlease see [our API settings documentation](https://www.openproject.org/docs/system-admin-guide/api-and-webhooks/) on\nhow to selectively enable CORS.\n\n## Allowed HTTP methods\n\n- `GET` - Get a single resource or collection of resources\n\n- `POST` - Create a new resource or perform\n\n- `PATCH` - Update a resource\n\n- `DELETE` - Delete a resource\n\n## Compression\n\nResponses are compressed if requested by the client. Currently [gzip](https://www.gzip.org/) and [deflate](https://tools.ietf.org/html/rfc1951)\nare supported. The client signals the desired compression by setting the [`Accept-Encoding` header](https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.3).\nIf no `Accept-Encoding` header is send, `Accept-Encoding: identity` is assumed which will result in the API responding uncompressed."
  title: OpenProject API V3 (Stable) Actions & Capabilities Custom Fields API
  version: '3'
servers:
- url: https://qa.openproject-edge.com
  description: Edge QA instance
- url: https://qa.openproject-stage.com
  description: Staging instance
- url: https://community.openproject.org
  description: Community instance
security:
- BasicAuth: []
tags:
- name: Custom Fields
paths:
  /api/v3/custom_fields/{id}/items:
    get:
      summary: Get the custom field hierarchy items
      operationId: get_custom_field_items
      description: 'Retrieves the hierarchy of custom fields.


        The hierarchy is a tree structure of hierarchy items. It is represented as a flat list of items, where each item

        has a reference to its parent and children. The list is ordered in a depth-first manner. The first item is the

        requested parent. If parent was unset, the root item is returned as first element.


        Passing the `depth` query parameter allows to limit the depth of the hierarchy. If the depth is unset, the full

        hierarchy tree is returned. If the depth is set to `0`, only the requested parent is returned. Any other positive

        integer will return the number of children levels specified by this value.


        This endpoint only returns, if the custom field is of type `hierarchy`.'
      parameters:
      - name: id
        description: The custom field's unique identifier
        in: path
        example: '42'
        required: true
        schema:
          type: integer
      - name: parent
        description: The identifier of the parent hierarchy item
        in: query
        example: '1337'
        required: false
        schema:
          type: integer
      - name: depth
        description: The level of hierarchy depth
        in: query
        example: '1'
        required: false
        schema:
          type: integer
      responses:
        '200':
          description: OK
          content:
            application/hal+json:
              schema:
                $ref: '#/components/schemas/HierarchyItemCollectionModel'
              examples:
                simple response:
                  $ref: '#/components/examples/HierarchyItemCollectionResponse'
                filtered response:
                  $ref: '#/components/examples/HierarchyItemCollectionFilteredResponse'
        '403':
          description: Returned if the user is not logged in.
          content:
            application/hal+json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
              examples:
                response:
                  value:
                    _type: Error
                    errorIdentifier: urn:openproject-org:api:v3:errors:MissingPermission
                    message: You are not authorized to access this resource.
        '404':
          description: Returned if the custom field does not exist or the user lacks the permission to view it.
          content:
            application/hal+json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
              examples:
                response:
                  value:
                    _type: Error
                    errorIdentifier: urn:openproject-org:api:v3:errors:NotFound
                    message: The requested resource could not be found.
        '422':
          description: Returned if the custom field is not of type hierarchy.
          content:
            application/hal+json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
              examples:
                response:
                  value:
                    _type: Error
                    errorIdentifier: urn:openproject-org:api:v3:errors:UnprocessableContent
                    message: The requested custom field resource is of wrong type.
      tags:
      - Custom Fields
components:
  schemas:
    HierarchyItemCollectionModel:
      allOf:
      - $ref: '#/components/schemas/CollectionModel'
      - type: object
        required:
        - _links
        - _embedded
        properties:
          _links:
            type: object
            required:
            - self
            properties:
              self:
                allOf:
                - $ref: '#/components/schemas/Link'
                - description: 'This hierarchy item collection


                    **Resource**: HierarchyItemCollectionModel'
          _embedded:
            type: object
            required:
            - elements
            properties:
              elements:
                type: array
                items:
                  $ref: '#/components/schemas/HierarchyItemReadModel'
    HierarchyItemReadModel:
      type: object
      required:
      - _type
      - id
      - label
      - short
      - weight
      - formattedWeight
      - depth
      - _links
      properties:
        _type:
          type: string
          enum:
          - HierarchyItem
        id:
          type: integer
          description: Hierarchy item identifier
        label:
          type:
          - string
          - 'null'
          description: The label of the hierarchy item
        short:
          type:
          - string
          - 'null'
          description: 'The short name of the hierarchy item. If this attribute is set, the `weight` and

            the `formattedWeight` are `null`.'
        weight:
          type:
          - string
          - 'null'
          description: 'The accurate weight of the hierarchy item. As a decimal precision number it is written as a string to

            not loose precision with conversion to a floating point number.

            If this attribute is set, the `short` is null.'
        formattedWeight:
          type:
          - string
          - 'null'
          description: 'The formatted weight of the hierarchy item. The standard formatting of the OpenProject server is used to

            convert this number into a representable format - i.e. falling back to scientific notation for very small and

            very big numbers.

            If this attribute is set, the `short` is null.'
        depth:
          type: integer
          description: The hierarchy depth. The root item has a depth of 0.
        _links:
          type: object
          required:
          - self
          - children
          - branch
          properties:
            self:
              allOf:
              - $ref: '#/components/schemas/Link'
              - description: 'This hierarchy item


                  **Resource**: HierarchyItem'
            parent:
              allOf:
              - $ref: '#/components/schemas/Link'
              - description: 'The hierarchy item that is the parent of the current hierarchy item


                  **Resource**: HierarchyItem'
            children:
              type: array
              items:
                allOf:
                - $ref: '#/components/schemas/Link'
                - description: 'A hierarchy item that is a child of the current hierarchy item


                    **Resource**: HierarchyItem'
            branch:
              allOf:
              - $ref: '#/components/schemas/Link'
              - description: 'The branch of the hierarchy item, ordered from root to node.


                  **Resource**: HierarchyItemCollection'
    CollectionModel:
      type: object
      required:
      - _type
      - total
      - count
      - _links
      properties:
        _type:
          type: string
          enum:
          - Collection
        total:
          type: integer
          description: The total amount of elements available in the collection.
          minimum: 0
        count:
          type: integer
          description: Actual amount of elements in this response.
          minimum: 0
        _links:
          $ref: '#/components/schemas/CollectionLinks'
    CollectionLinks:
      type: object
      required:
      - self
      properties:
        self:
          allOf:
          - $ref: '#/components/schemas/Link'
          - description: 'This collection resource.


              **Resource**: Collection'
    Link:
      type: object
      required:
      - href
      properties:
        href:
          type:
          - string
          - 'null'
          description: URL to the referenced resource (might be relative)
        title:
          type: string
          description: Representative label for the resource
        templated:
          type: boolean
          default: false
          description: If true the href contains parts that need to be replaced by the client
        method:
          type: string
          default: GET
          description: The HTTP verb to use when requesting the resource
        payload:
          type: object
          description: The payload to send in the request to achieve the desired result
        identifier:
          type: string
          description: An optional unique identifier to the link object
        type:
          type: string
          description: The MIME-Type of the returned resource.
      example:
        href: /api/v3/work_packages
        method: POST
    ErrorResponse:
      type: object
      required:
      - _type
      - errorIdentifier
      - message
      properties:
        _embedded:
          type: object
          properties:
            details:
              type: object
              properties:
                attribute:
                  type: string
                  example: project
        _type:
          type: string
          enum:
          - Error
        errorIdentifier:
          type: string
          example: urn:openproject-org:api:v3:errors:PropertyConstraintViolation
        message:
          type: string
          example: Project can't be blank.
  examples:
    HierarchyItemCollectionResponse:
      description: Simple response of a hierarchy structure starting at root.
      value:
        _type: Collection
        total: 37
        count: 37
        _embedded:
          elements:
          - _type: HierarchyItem
            id: 1337
            label: null
            short: null
            weight: null
            formattedWeight: null
            depth: 0
            _links:
              self:
                href: /api/v3/custom_field_items/1337
              branch:
                href: /api/v3/custom_field_items/1337/branch
              children:
              - href: /api/v3/custom_field_items/1338
                name: Stormtroopers
              - href: /api/v3/custom_field_items/1339
                name: Dark Troopers
          - _type: HierarchyItem
            id: 1338
            label: Stormtroopers
            short: ST
            weight: null
            formattedWeight: null
            depth: 1
            _links:
              self:
                href: /api/v3/custom_field_items/1338
                name: Stormtroopers
              parent:
                href: /api/v3/custom_field_items/1337
                name: Imperial Troopers
              branch:
                href: /api/v3/custom_field_items/1338/branch
              children:
              - href: /api/v3/custom_field_items/1340
                name: ST-377
              - href: /api/v3/custom_field_items/1341
                name: ST-422
          - _type: HierarchyItem
            id: 1340
            label: ST-377
            short: null
            weight: null
            formattedWeight: null
            depth: 2
            _links:
              self:
                href: /api/v3/custom_field_items/1340
              branch:
                href: /api/v3/custom_field_items/1340/branch
              children: []
        _links:
          self:
            href: /api/v3/custom_field/42/items
    HierarchyItemCollectionFilteredResponse:
      description: Filtered response of a hierarchy structure starting at a specific parent and restricting the depth.
      value:
        _type: Collection
        total: 3
        count: 3
        _embedded:
          elements:
          - _type: HierarchyItem
            id: 1338
            label: Stormtroopers
            short: ST
            weight: null
            formattedWeight: null
            depth: 1
            _links:
              self:
                href: /api/v3/custom_field_items/1338
                name: Stormtroopers
              parent:
                href: /api/v3/custom_field_items/1337
                name: null
              branch:
                href: /api/v3/custom_field_items/1338/branch
              children:
              - href: /api/v3/custom_field_items/1340
                name: ST-377
              - href: /api/v3/custom_field_items/1341
                name: ST-422
          - _type: HierarchyItem
            id: 1340
            label: ST-377
            short: null
            weight: null
            formattedWeight: null
            depth: 2
            _links:
              self:
                href: /api/v3/custom_field_items/1340
                name: ST-377
              parent:
                href: /api/v3/custom_field_items/1338
                name: Stormtroopers
              branch:
                href: /api/v3/custom_field_items/1340/branch
              children:
              - href: /api/v3/custom_field_items/1480
                name: ST-377-200
              - href: /api/v3/custom_field_items/1481
                name: ST-377-201
          - _type: HierarchyItem
            id: 1341
            label: ST-422
            short: null
            weight: null
            formattedWeight: null
            depth: 2
            _links:
              self:
                href: /api/v3/custom_field_items/1341
                name: ST-422
              parent:
                href: /api/v3/custom_field_items/1338
                name: Stormtroopers
              branch:
                href: /api/v3/custom_field_items/1341/branch
              children:
              - href: /api/v3/custom_field_items/1580
                name: ST-422-137
              - href: /api/v3/custom_field_items/1581
                name: ST-422-138
        _links:
          self:
            href: /api/v3/custom_field/42/items?parent=1338&depth=1
  securitySchemes:
    BasicAuth:
      type: http
      scheme: basic