openapi: 3.0.3
info:
  title: Apptainer Container Runtime API
  description: >-
    API for the Apptainer container runtime, enabling programmatic management of
    HPC container images, instances, and execution for scientific computing workloads.
    Apptainer (formerly Singularity) is optimized for high-performance computing with
    support for Docker/OCI containers and HPC schedulers.
  version: 1.0.0
  contact:
    name: Apptainer Project
    url: https://apptainer.org/docs/
  license:
    name: BSD 3-Clause
    url: https://opensource.org/licenses/BSD-3-Clause
servers:
  - url: https://api.apptainer.org/v1
    description: Apptainer API
security:
  - bearerAuth: []
tags:
  - name: Images
    description: Container image management
  - name: Instances
    description: Running container instance management
paths:
  /images:
    get:
      operationId: listImages
      summary: Apptainer - List Images
      description: Returns a list of Apptainer container images available in the registry
      tags:
        - Images
      parameters:
        - name: format
          in: query
          description: Filter by image format (SIF or sandbox)
          schema:
            type: string
            enum: [SIF, sandbox]
        - name: name
          in: query
          description: Filter by image name
          schema:
            type: string
      responses:
        '200':
          description: A list of container images
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/ContainerImage'
              examples:
                ListImagesExample:
                  x-microcks-default: true
                  summary: Example container images list
                  value:
                    data:
                      - imageId: img-ubuntu-22.04-hpc
                        name: ubuntu-hpc
                        version: "22.04"
                        format: SIF
                        size: 75497472
        '401':
          description: Unauthorized - invalid or missing authentication token
    post:
      operationId: pullImage
      summary: Apptainer - Pull Image
      description: Pulls a container image from a source URI into the local registry
      tags:
        - Images
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                source:
                  type: string
                  description: Source URI for the container image (docker://, library://, oras://)
                name:
                  type: string
                  description: Local name for the pulled image
            examples:
              PullImageExample:
                x-microcks-default: true
                summary: Example image pull request
                value:
                  source: docker://ubuntu:22.04
                  name: ubuntu-hpc
      responses:
        '201':
          description: Image pulled successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ContainerImage'
        '400':
          description: Invalid source URI
        '401':
          description: Unauthorized - invalid or missing authentication token
  /images/{imageId}:
    get:
      operationId: getImage
      summary: Apptainer - Get Image
      description: Returns details for a specific container image
      tags:
        - Images
      parameters:
        - name: imageId
          in: path
          required: true
          description: Unique container image identifier
          schema:
            type: string
      responses:
        '200':
          description: Container image details
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ContainerImage'
              examples:
                GetImageExample:
                  x-microcks-default: true
                  summary: Example image detail
                  value:
                    imageId: img-ubuntu-22.04-hpc
                    name: ubuntu-hpc
                    version: "22.04"
                    source: docker://ubuntu:22.04
                    format: SIF
                    size: 75497472
                    createdAt: "2026-01-10T08:00:00Z"
                    sha256: a1b2c3d4e5f6
        '404':
          description: Image not found
        '401':
          description: Unauthorized - invalid or missing authentication token
  /instances:
    get:
      operationId: listInstances
      summary: Apptainer - List Instances
      description: Returns a list of running Apptainer container instances
      tags:
        - Instances
      responses:
        '200':
          description: A list of running instances
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/ContainerInstance'
              examples:
                ListInstancesExample:
                  x-microcks-default: true
                  summary: Example instances list
                  value:
                    data:
                      - instanceId: inst-001
                        name: my-simulation
                        imageId: img-ubuntu-22.04-hpc
                        status: running
                        startedAt: "2026-04-19T09:00:00Z"
        '401':
          description: Unauthorized - invalid or missing authentication token
    post:
      operationId: startInstance
      summary: Apptainer - Start Instance
      description: Starts a new container instance from an Apptainer image
      tags:
        - Instances
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                imageId:
                  type: string
                  description: Image to run as a container instance
                name:
                  type: string
                  description: Name for the container instance
                command:
                  type: string
                  description: Optional command to run in the container
            examples:
              StartInstanceExample:
                x-microcks-default: true
                summary: Example instance start request
                value:
                  imageId: img-ubuntu-22.04-hpc
                  name: my-simulation
                  command: /bin/bash run_simulation.sh
      responses:
        '201':
          description: Instance started successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ContainerInstance'
        '400':
          description: Invalid request body
        '401':
          description: Unauthorized - invalid or missing authentication token
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
  schemas:
    ContainerImage:
      title: ContainerImage
      description: An Apptainer container image in SIF or sandbox format
      type: object
      properties:
        imageId:
          type: string
          description: Unique container image identifier
        name:
          type: string
          description: Container image name
        version:
          type: string
          description: Image version
        source:
          type: string
          description: Source URI (docker://, library://, oras://)
        format:
          type: string
          enum: [SIF, sandbox]
          description: Container image format
        size:
          type: integer
          description: Image size in bytes
        createdAt:
          type: string
          format: date-time
          description: Image creation timestamp
        sha256:
          type: string
          description: SHA-256 hash for verification
    ContainerInstance:
      title: ContainerInstance
      description: A running Apptainer container instance
      type: object
      properties:
        instanceId:
          type: string
          description: Unique instance identifier
        name:
          type: string
          description: Instance name
        imageId:
          type: string
          description: Container image the instance runs
        status:
          type: string
          enum: [running, stopped, error]
          description: Instance status
        startedAt:
          type: string
          format: date-time
          description: Instance start timestamp
        stoppedAt:
          type: string
          format: date-time
          description: Instance stop timestamp