Crossplane Functions API

openapi: 3.2.0
info:
  title: Crossplane Kubernetes Functions API
  description: The Crossplane Kubernetes API extends the Kubernetes API server with custom resources for managing cloud infrastructure declaratively.
  version: '2.2'
  contact:
    name: Crossplane Community
    url: https://slack.crossplane.io/
  termsOfService: https://www.crossplane.io/
servers:
- url: https://kubernetes.default.svc
  description: Kubernetes API Server (in-cluster)
security:
- bearerAuth: []
tags:
- name: Functions
  description: Functions are Crossplane packages that contain Composition Functions, which are OCI container images invoked during composition to perform advanced resource templating and transformation logic.
paths:
  /apis/pkg.crossplane.io/v1/functions:
    get:
      operationId: listFunctions
      summary: Crossplane List Functions
      description: Returns a list of all Composition Function package installations. Functions are OCI images that implement the Composition Function gRPC protocol and are invoked as pipeline steps during composition.
      tags:
      - Functions
      parameters:
      - $ref: '#/components/parameters/labelSelector'
      - $ref: '#/components/parameters/limit'
      - $ref: '#/components/parameters/continueToken'
      responses:
        '200':
          description: Successfully listed Functions.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/FunctionList'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createFunction
      summary: Crossplane Install a Function
      description: Installs a new Composition Function by referencing its OCI package image. Once installed, the Function can be referenced in Composition pipeline steps by name.
      tags:
      - Functions
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Function'
      responses:
        '201':
          description: Function installation initiated.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Function'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '409':
          $ref: '#/components/responses/Conflict'
  /apis/pkg.crossplane.io/v1/functions/{name}:
    get:
      operationId: getFunction
      summary: Crossplane Get a Function
      description: Returns details of a specific Composition Function installation, including its package image reference and status conditions reflecting whether the function is healthy and ready to serve composition requests.
      tags:
      - Functions
      parameters:
      - $ref: '#/components/parameters/name'
      responses:
        '200':
          description: Successfully retrieved the Function.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Function'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deleteFunction
      summary: Crossplane Uninstall a Function
      description: Removes a Composition Function installation. Compositions that reference this Function in their pipeline will fail to reconcile until the Function reference is removed or the Function is reinstalled.
      tags:
      - Functions
      parameters:
      - $ref: '#/components/parameters/name'
      responses:
        '200':
          description: Function uninstallation initiated.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Status'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    BadRequest:
      description: The request was malformed or failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    Unauthorized:
      description: Authentication credentials are missing or invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    Conflict:
      description: A resource with this name already exists.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
  parameters:
    continueToken:
      name: continue
      in: query
      required: false
      description: Token returned by a previous list call to retrieve the next page of results. This token encodes list position and expiration time.
      schema:
        type: string
    name:
      name: name
      in: path
      required: true
      description: Name of the Crossplane resource.
      schema:
        type: string
    limit:
      name: limit
      in: query
      required: false
      description: Maximum number of items to return in a single response. The server may return fewer items than requested. Use the continue token for pagination.
      schema:
        type: integer
        minimum: 1
    labelSelector:
      name: labelSelector
      in: query
      required: false
      description: A selector to restrict the list of returned objects by their labels. Defaults to everything.
      schema:
        type: string
  schemas:
    Status:
      type: object
      description: A Kubernetes API Status response used for errors and operation results.
      properties:
        apiVersion:
          type: string
          description: API version of the Status object.
        kind:
          type: string
          const: Status
          description: Always Status.
        status:
          type: string
          description: Status of the operation, Success or Failure.
        message:
          type: string
          description: Human-readable description of the status.
        reason:
          type: string
          description: Machine-readable reason for the status, such as NotFound or AlreadyExists.
        code:
          type: integer
          description: HTTP status code corresponding to this status.
    Function:
      type: object
      description: A Crossplane Composition Function package. Functions implement the Composition Function gRPC protocol and are invoked as steps in a Composition pipeline to template composed resources.
      required:
      - apiVersion
      - kind
      - metadata
      - spec
      properties:
        apiVersion:
          type: string
          const: pkg.crossplane.io/v1
          description: API version for the Function resource.
        kind:
          type: string
          const: Function
          description: Resource kind identifier.
        metadata:
          $ref: '#/components/schemas/ObjectMeta'
        spec:
          $ref: '#/components/schemas/PackageSpec'
        status:
          $ref: '#/components/schemas/PackageStatus'
    FunctionList:
      type: object
      description: A list of Function resources.
      required:
      - apiVersion
      - kind
      - items
      properties:
        apiVersion:
          type: string
          description: API version for the list resource.
        kind:
          type: string
          const: FunctionList
          description: List kind identifier.
        metadata:
          type: object
          properties:
            resourceVersion:
              type: string
              description: Resource version of the list.
            continue:
              type: string
              description: Continuation token for pagination.
        items:
          type: array
          description: List of Function resources.
          items:
            $ref: '#/components/schemas/Function'
    ObjectMeta:
      type: object
      description: Standard Kubernetes object metadata.
      required:
      - name
      properties:
        name:
          type: string
          description: Unique name of the resource within its scope.
        namespace:
          type: string
          description: Namespace of the resource. Crossplane core resources are cluster-scoped and do not use namespace.
        labels:
          type: object
          description: Key-value pairs for organizing and selecting resources.
          additionalProperties:
            type: string
        annotations:
          type: object
          description: Non-identifying metadata attached to the resource.
          additionalProperties:
            type: string
        resourceVersion:
          type: string
          description: Opaque string that identifies the version of the resource for optimistic concurrency.
        uid:
          type: string
          description: Unique identifier for the resource assigned by the API server.
        generation:
          type: integer
          description: Sequence number for changes to the spec. Incremented by the API server on spec changes.
        creationTimestamp:
          type: string
          format: date-time
          description: Timestamp when the resource was created.
        deletionTimestamp:
          type: string
          format: date-time
          description: Timestamp after which the resource will be deleted, set when deletion is requested.
        finalizers:
          type: array
          description: Finalizers that must be cleared before the object is deleted.
          items:
            type: string
    PackageStatus:
      type: object
      description: Common status fields for Crossplane package resources.
      properties:
        currentRevision:
          type: string
          description: Name of the currently active package revision.
        conditions:
          type: array
          description: Status conditions for the package.
          items:
            $ref: '#/components/schemas/Condition'
    Condition:
      type: object
      description: A status condition for a Crossplane resource.
      required:
      - type
      - status
      properties:
        type:
          type: string
          description: Type of condition, such as Ready, Synced, or Healthy.
        status:
          type: string
          enum:
          - 'True'
          - 'False'
          - Unknown
          description: Status of the condition.
        reason:
          type: string
          description: Machine-readable reason for the condition's last transition.
        message:
          type: string
          description: Human-readable message describing the current condition state.
        lastTransitionTime:
          type: string
          format: date-time
          description: Timestamp of the last transition for this condition.
    PackageSpec:
      type: object
      description: Common specification fields for Crossplane package resources (Provider, Function, Configuration).
      required:
      - package
      properties:
        package:
          type: string
          description: OCI image reference for the package, including registry, repository, and tag or digest.
        packagePullPolicy:
          type: string
          enum:
          - Always
          - IfNotPresent
          - Never
          description: Image pull policy for fetching the package OCI image.
        packagePullSecrets:
          type: array
          description: References to Kubernetes secrets containing OCI registry credentials.
          items:
            type: object
            required:
            - name
            properties:
              name:
                type: string
                description: Name of the image pull secret.
        revisionActivationPolicy:
          type: string
          enum:
          - Automatic
          - Manual
          description: Policy for activating new package revisions. Automatic activates immediately; Manual requires explicit activation.
        revisionHistoryLimit:
          type: integer
          minimum: 0
          description: Number of inactive package revisions to retain for rollback.
        runtimeConfigRef:
          type: object
          description: Reference to a DeploymentRuntimeConfig for customizing the package's runtime deployment.
          required:
          - name
          properties:
            name:
              type: string
              description: Name of the DeploymentRuntimeConfig.
            apiVersion:
              type: string
              description: API version of the referenced resource.
            kind:
              type: string
              description: Kind of the referenced resource.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: Kubernetes service account token or user bearer token for authenticating with the Kubernetes API server. RBAC policies control which Crossplane resources each identity can access.
externalDocs:
  description: Crossplane API Reference
  url: https://docs.crossplane.io/latest/api/