IonQ Backends API

openapi: 3.2.0
info:
  title: IonQ Cloud Platform Backends API
  version: v0.2
  description: '*Last updated: October 19, 2026*

    # Introduction

    Welcome to the IonQ platform! You can use our API and the `qcloud` command-line interface to submit and retrieve jobs on our quantum hardware as well as our high-performance simulator.


    Our API uses the REST architectural style; this means we provide unsurprising, resource-oriented URLs and take advantage of built-in HTTP response codes, authentication, verbs, and other features.

    We allow cross-site requests from any domain, and return JSON responses.


    If you prefer to not think about HTTP, use our OpenAPI spec to generate bindings for your language of choice. Pre-generated bindings for Python and JavaScript are coming soon.


    ## Non-breaking changes


    * Histogram example expanded to include scientific notation for a JSON numeric value.


    ## Migrating to v0.2


    ### Breaking changes


    * Calibrations endpoints has been deprecated in favor of Characterizations.


    ### New features


    * Ability to specifify target hardware generation on Job creation. e.g. `qpu.harmony` for targeting our 11-qubit system.

    * Introduces Characterizations endpoints. Enables fetching current and historic characterizations for specific targets.

    * Backends availability and other stats can now be fetched.


    ## Migrating to v0.1


    ### Breaking changes


    Prerelease version `v0.1` has one major breaking change from `v0`:


    * Canceling jobs is now done via a PUT. This allows us to more naturally support job deletion.


    ### New features


    * Completely deleting one or more jobs is now possible

    * Multiple jobs may be canceled simultaneously

    * A list of jobs may be fetched simultaneously


    ## API status


    API and quantum computer status is continuously reported at https://status.ionq.co/.

    Please subscribe for automated updates when we perform maintenance or experience an outage.


    In addition, you may use the status endpoint to check the current status of our API.


    ## Authentication'
  contact:
    name: IonQ
    email: support@ionq.co
    url: https://ionq.com/
  x-logo:
    url: https://static.ionq.co/images/ionq-logo-dark.png
    altText: IonQ Logo
    href: '#'
servers:
- url: https://api.ionq.co/v0.2
  description: Current Endpoint
- url: https://api.ionq.co/v0.1
basePath: /v0.2
security:
- API Key: []
tags:
- name: Backends
  x-displayName: Backends
  description: 'Jobs can be run on different target hardware, known as backends.

    Backends can also define a generation from its its name, such as `qpu.harmony`. A generation comprises a different

    set of capabilities that may better suit the requirements of your target program.'
paths:
  /backends:
    get:
      operationId: getBackends
      summary: Get Backends
      description: This endpoint retrieves all backends.
      security: []
      tags:
      - Backends
      responses:
        '200':
          description: Successfully retrieved backends.
          content:
            application/json:
              schema:
                type: object
                description: A list of backends you can target your program to run on.
                required:
                - backend
                - status
                - qubits
                - average_queue_time
                - updated
                properties:
                  backend:
                    type: string
                    example: qpu.s11
                    description: Specifies target hardware and generation where applies.
                  status:
                    type: string
                    description: Current availability.
                    enum:
                    - available
                    - unavailable
                  average_queue_time:
                    type: number
                    format: unix-timestamp
                    example: 1181215
                    description: Current wait time on the queue for execution.
                  last_updated:
                    type: integer
                    example: 1490932820
                    description: Last time the backend status was updated.
                  characterization_url:
                    type: string
                    example: /characterizations/617a1f8b-59d4-435d-aa33-695433d7155e
                    description: Current characterization for this backend
      x-codeSamples:
      - lang: curl
        source: 'curl "https://api.ionq.co/v0.2/backends"

          '
components:
  securitySchemes:
    API_Key:
      in: header
      name: Authorization
      type: apiKey
      description: 'We provide API keys to govern access—we''ll provision your account with one key, and more can be provided upon request.


        Every key is fully privileged within the system, and should be kept private.


        To authenticate, prefix your API Key with `apiKey ` and place it in the `Authorization` request header.

        For example: `Authorization: apiKey your-api-key`

        '
x-tagGroups:
- name: Managing Jobs
  tags:
  - jobs
- name: Building Circuits
  tags:
  - quantum_programs
- name: Characterization Data
  tags:
  - calibrations
  - characterizations
- name: Backends
  tags:
  - backends
- name: User Metadata
  tags:
  - metadata
- name: API Features
  tags:
  - api-feature-pagination
  - api-feature-response-status
- name: Telemetry
  tags:
  - status
x-provenance:
  method: harvested
  publisher: IonQ
  source: https://api.ionq.co/api-docs
  note: split by refine-openapis from the provider's own published document, verified by fetch (openapi/_original/*.fetch.json);
    stamped by stamp-openapi-provenance.py (roadmap#793)