Use Flux 2 Flex through Rivya Public API v1 with model id flux-2-flex, supported inputs, parameters, Files API rules, credits, and response examples.

Available via APIText or URL ready; reference modes use Files APIImage

API model id

flux-2-flex

Inputs

text, file

Files API

Required for reference modes

Base credits

Capability

Image

Billing

FIXED

Prompt limit

5000 characters

Request contract

Send the model id at the top level. Model-specific controls belong in params.

Key	Type	Required	Default	Description
model	string	Yes	flux-2-flex	Use the flux-2-flex API model id.
prompt	string	Yes	-	Maximum 5000 characters for this model.
params	object	No	-	Model-specific parameter object. Use the rows below for allowed keys.
client_request_id	string	No	-	Optional client-side id for tracing requests in your system.

Model parameters

Key	Type	Required	Default	Range	Options	Description
aspectRatio	select	No	1:1	-	1:1, 4:3, 3:4, 16:9, 9:16, 3:2, 2:3	Aspect ratio
resolution	select	No	1K	-	1K, 2K	Resolution

Upload policy

Upload reference files first, then place the returned URL and duration token inside params.referenceMediaItems.

Reference rule

Reference image: Upload up to 8 image files for image projects.

Max files

Accepted file kinds

image

Duration token

Video and audio references should carry durationToken from /api/v1/files when duration verification is required.

kind	Max size	MIME types
image	10 MB	image/jpeg, image/png, image/webp

Minimal request

{
  "model": "flux-2-flex",
  "prompt": "A clean editorial product image on a soft studio background",
  "params": {
    "aspectRatio": "1:1",
    "resolution": "1K"
  }
}

Reference-file request

{
  "model": "flux-2-flex",
  "prompt": "A clean editorial product image on a soft studio background",
  "params": {
    "aspectRatio": "1:1",
    "resolution": "1K",
    "referenceMediaItems": [
      {
        "url": "https://cdn.example.com/reference-image.png",
        "kind": "image",
        "name": "reference-image.png",
        "mimeType": "image/png"
      }
    ]
  }
}

Create response

The create endpoint returns a public task id. Poll the status endpoint until the task succeeds or fails.

{
  "id": "task_flux_2_flex_example",
  "status": "queued",
  "model": "flux-2-flex",
  "reserved_credits": 14,
  "final_credits": 0,
  "created_at": "2026-05-11T00:00:00.000Z",
  "updated_at": "2026-05-11T00:00:00.000Z",
  "result": null,
  "error": null
}

Common errors

validation_failed, insufficient_credits, idempotency_conflict, rate_limited, not_found

Some modes require Files API reference uploads.

Flux 2 Flex API Integration