Crossplane Functions API

openapi: 3.1.0
info:
  title: Crossplane Kubernetes CompositeResourceDefinitions Functions API
  description: 'The Crossplane Kubernetes API extends the Kubernetes API server with custom resources for managing cloud infrastructure declaratively. Resources are organized into two main API groups: apiextensions.crossplane.io for composition primitives (Compositions, CompositeResourceDefinitions, EnvironmentConfigs) and pkg.crossplane.io for package management (Providers, Functions, Configurations and their revisions). All operations use standard Kubernetes REST conventions and are authenticated through the Kubernetes API server''s authentication mechanisms.'
  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:
  parameters:
    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
    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
  responses:
    Unauthorized:
      description: Authentication credentials are missing or invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
    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'
    Conflict:
      description: A resource with this name already exists.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Status'
  schemas:
    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'
    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'
    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'
    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.
    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
    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.
    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.
  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/