> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mage.space/llms.txt
> Use this file to discover all available pages before exploring further.

# Flux 2

> Generate images with Flux 2 through the Mage API: the fields of POST /v1/flux2/generate, its options by model, the rules it enforces, and its gem price.

An image model for generation and for edits from up to three reference images.

| Detail       |                                                                              |
| ------------ | ---------------------------------------------------------------------------- |
| Type         | Image                                                                        |
| Models       | `flux2-dev` (default)                                                        |
| Image inputs | `image` (reference image), `additional_images` (additional reference images) |
| Video inputs | None                                                                         |
| Gems         | 40 at the default settings                                                   |
| Model page   | [Flux, Flux 2, and Flux Kontext Dev](/models/flux)                           |

Every field below that you leave out keeps its default. Option values are the raw tokens listed per field; a numeric token may be sent as a number. Fields the schema does not list pass through to the model unchanged. The exact charge for other settings is in the response's `billing.gems_charged`, and the balance at [`GET /v1/account`](/api/endpoints/get-account).


## OpenAPI

````yaml api/openapi.json POST /v1/flux2/generate
openapi: 3.1.0
info:
  title: Mage API
  version: v1
  description: >-
    Run Mage models from your own code: submit a generation, poll its status,
    download the result. Every request is paid in gems.
  contact:
    name: Mage
    url: https://www.mage.space
    email: mage@mage.space
servers:
  - url: https://api.mage.space
    description: Production
security:
  - apiKey: []
tags:
  - name: Requests
    description: Submit, poll, and cancel generations.
  - name: Catalog
    description: What the API can generate with.
  - name: Account
    description: The gems balance.
  - name: Uploads
    description: Large input files.
  - name: Image models
    description: One endpoint per image architecture.
  - name: Video models
    description: One endpoint per video architecture.
paths:
  /v1/flux2/generate:
    post:
      tags:
        - Image models
      summary: Flux 2
      description: Generate an image with Flux 2.
      operationId: generate_flux2
      parameters:
        - name: Idempotency-Key
          in: header
          required: false
          description: >-
            A key of your choosing, 1 to 255 characters, scoped to your API key.
            A retried submit with the same key returns the original request with
            `200` instead of charging again. The key identifies the first
            submission made with it; later bodies are not compared. A refusal
            recorded under the key (its envelope carries `request_id`) replays
            the same way, so a new attempt needs a new key.
          schema:
            type: string
            minLength: 1
            maxLength: 255
      requestBody:
        required: true
        description: A partial config for Flux 2.
        content:
          application/json:
            schema:
              type: object
              properties:
                prompt:
                  type: string
                  minLength: 1
                  description: The text prompt.
                seed:
                  description: >-
                    Integer seed for reproducible output; omit or send null for
                    a random seed.
                  anyOf:
                    - type: integer
                    - type: 'null'
                model_id:
                  type: string
                  enum:
                    - flux2-dev
                  description: The model variant to generate with.
                  default: flux2-dev
                aspect_ratio:
                  type: string
                  enum:
                    - ultrawide
                    - cinema
                    - landscape
                    - computer
                    - square
                    - portrait
                    - tablet
                    - phone
                    - ultratall
                  description: Aspect ratio token.
                  default: portrait
                resolution:
                  type: string
                  enum:
                    - 1k
                    - 2k
                  description: Output resolution token.
                  default: 1k
                image:
                  anyOf:
                    - type: string
                      format: uri
                    - type: string
                      pattern: ^data:[^;,]+(?:;[^;,]+)*;base64,
                  description: The reference image. An https URL or a data URL.
                additional_images:
                  type: array
                  items:
                    anyOf:
                      - type: string
                        format: uri
                      - type: string
                        pattern: ^data:[^;,]+(?:;[^;,]+)*;base64,
                  description: >-
                    Additional reference images. Each an https URL or a data
                    URL.
                num_inference_steps:
                  type: number
                  default: 28
                guidance_scale:
                  type: number
                  default: 4
              required:
                - prompt
              additionalProperties: true
            example:
              prompt: Editorial portrait in soft daylight, 35mm film look
              aspect_ratio: portrait
      responses:
        '202':
          description: >-
            The request was accepted; poll `status_url` for the result. A
            retried submit whose `Idempotency-Key` was used before answers `200`
            with the same shape, the original request, and charges nothing.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Request'
              example:
                request_id: d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff
                status: in_progress
                architecture: flux2
                model_id: flux2-dev
                created_at: '2026-09-17T14:52:48.000Z'
                updated_at: '2026-09-17T14:52:49.000Z'
                billing:
                  mode: gems
                  gems_charged: 40
                result: null
                error: null
                status_url: >-
                  https://api.mage.space/v1/requests/d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff/status
                cancel_url: >-
                  https://api.mage.space/v1/requests/d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff/cancel
        '400':
          $ref: '#/components/responses/InvalidGenerateRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/InsufficientGems'
        '403':
          $ref: '#/components/responses/GenerationForbidden'
        '410':
          $ref: '#/components/responses/ArchitectureRetired'
        '429':
          $ref: '#/components/responses/TooManyRequests'
        '451':
          $ref: '#/components/responses/ExternalContentBlock'
        '500':
          $ref: '#/components/responses/InternalError'
components:
  schemas:
    Request:
      type: object
      properties:
        request_id:
          type: string
          format: uuid
          description: The request id, also the id in `status_url` and `cancel_url`.
        status:
          type: string
          enum:
            - queued
            - in_progress
            - completed
            - failed
            - cancelled
          description: >-
            `queued` and `in_progress` are live; `completed`, `failed`, and
            `cancelled` are final.
        architecture:
          type: string
          description: The architecture the request generates with.
        model_id:
          anyOf:
            - type: string
            - type: 'null'
          description: The model variant, when the architecture has variants.
        created_at:
          type: string
          format: date-time
          description: When the request was accepted.
        updated_at:
          type: string
          format: date-time
          description: When the request last changed.
        billing:
          type: object
          properties:
            mode:
              type: string
              const: gems
              description: Every API request is paid in gems.
            gems_charged:
              type: number
              description: Gems debited for the request.
            gems_refunded:
              description: Gems returned to the account; present on failed requests.
              type: number
          required:
            - mode
            - gems_charged
          additionalProperties: false
        result:
          anyOf:
            - type: object
              properties:
                type:
                  type: string
                  enum:
                    - image
                    - video
                    - audio
                  description: The media type of the output.
                url:
                  type: string
                  format: uri
                  description: Where to download the output.
                width:
                  type: integer
                  description: Output width in pixels.
                height:
                  type: integer
                  description: Output height in pixels.
                seed:
                  type: integer
                  description: The seed the generation ran with.
                expires_at:
                  anyOf:
                    - type: string
                      format: date-time
                    - type: 'null'
                  description: >-
                    When `url` stops working: 30 days after the request for
                    temporary media, or null for permanent media.
                moderation:
                  type: object
                  properties:
                    nsfw:
                      type: boolean
                      description: Whether moderation flagged the output as NSFW.
                  required:
                    - nsfw
                  additionalProperties: false
                  description: Moderation flags on the output.
              required:
                - type
                - url
                - width
                - height
                - seed
                - expires_at
                - moderation
              additionalProperties: false
            - type: 'null'
          description: The output once `status` is `completed`, else null.
        error:
          anyOf:
            - type: object
              properties:
                code:
                  type: string
                  enum:
                    - unauthorized
                    - invalid_request
                    - invalid_config
                    - architecture_not_found
                    - architecture_retired
                    - request_not_found
                    - not_found
                    - insufficient_gems
                    - forbidden
                    - content_blocked
                    - request_finished
                    - too_many_requests
                    - generation_failed
                    - internal_error
                  description: A stable error code.
                message:
                  type: string
                  description: What went wrong, for a person.
              required:
                - code
                - message
              additionalProperties: false
            - type: 'null'
          description: Why the request failed once `status` is `failed`, else null.
        status_url:
          type: string
          format: uri
          description: Poll this URL for the request.
        cancel_url:
          type: string
          format: uri
          description: POST to this URL to stop the request.
      required:
        - request_id
        - status
        - architecture
        - model_id
        - created_at
        - updated_at
        - billing
        - result
        - error
        - status_url
        - cancel_url
      additionalProperties: false
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
              enum:
                - unauthorized
                - invalid_request
                - invalid_config
                - architecture_not_found
                - architecture_retired
                - request_not_found
                - not_found
                - insufficient_gems
                - forbidden
                - content_blocked
                - request_finished
                - too_many_requests
                - generation_failed
                - internal_error
              description: A stable error code; treat an unknown code by its HTTP status.
            message:
              type: string
              description: What went wrong, for a person.
            request_id:
              description: >-
                The request the refusal belongs to, when one was recorded before
                the refusal.
              type: string
              format: uuid
            gems_required:
              description: The price of the refused generation, on `insufficient_gems`.
              type: number
            docs_url:
              description: Where to read the API reference, on `not_found`.
              type: string
              format: uri
          required:
            - code
            - message
          additionalProperties: true
          description: Further fields depend on the code.
      required:
        - error
      additionalProperties: false
  responses:
    InvalidGenerateRequest:
      description: >-
        The body is not a JSON object, sets a server-owned field, contradicts
        the architecture, breaks a field's type or token list, or breaks a model
        rule; or the `Idempotency-Key` is malformed. `invalid_config` names the
        field or the rule.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: invalid_config
              message: '`resolution` must be one of: 768P, 2K.'
    Unauthorized:
      description: The key is missing, malformed, unknown, or revoked.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: unauthorized
              message: The API key is invalid or has been revoked.
    InsufficientGems:
      description: The gems balance is below the price. `gems_required` is the price.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: insufficient_gems
              message: >-
                This generation costs 40 gems and the account balance is too
                low.
              request_id: d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff
              gems_required: 40
    GenerationForbidden:
      description: >-
        The account cannot generate (`forbidden`), or the request was blocked by
        the content policy before it ran (`content_blocked`).
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: content_blocked
              message: The request was blocked by Mage's content policy.
              request_id: d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff
    ArchitectureRetired:
      description: The architecture has been retired.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: architecture_retired
              message: This architecture has been retired.
              request_id: d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff
    TooManyRequests:
      description: >-
        The account already has its cap of generations in flight (20 unless set
        otherwise for the account), web and API together. Wait for some to
        finish.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: too_many_requests
              message: >-
                At most 20 generations may be in flight at once for this
                account; 20 are running now.
    ExternalContentBlock:
      description: The request was blocked by an external content restriction.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: content_blocked
              message: The request was blocked by an external content restriction.
              request_id: d7e6c0f3-6699-4f6c-bb45-2ad7fd9158ff
    InternalError:
      description: >-
        Something failed on Mage's side. Retry, and contact support if it
        persists.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            error:
              code: internal_error
              message: >-
                Something went wrong on our side. Retry, and contact support if
                it persists.
  securitySchemes:
    apiKey:
      type: http
      scheme: bearer
      description: >-
        An API key from Settings → API, sent as `Authorization: Bearer
        mage_sk_…`. Keys are for server-side code only.

````