FLUX.2 pro edit takes 9 references, 9MP total: price effect

FLUX.2 [pro] Edit on fal accepts up to 9 reference images with 9 MP of input in total, and its price counts input megapixels as well as output: $0.03 for the first output megapixel, then $0.015 per extra megapixel of input and output, rounded up. More references therefore raise the bill even when the output stays 1 MP. Sume's catalog tells you how many references its row accepts, so read it before you plan a 9-image edit.

Figures are from fal's FLUX.2 pro edit page, read 2026-10-03.

What fal states

The page gives the formula and the 9-reference, 9 MP cap. Rounding is to the nearest megapixel. It does not state a per-image reference size, so the table shows the formula only.

Check what Sume bills

The docs say endpoint pricing lines are the amount charged to your wallet. Print them for the row Sume lists and compare against fal's formula; Sume's lines may not use the same units.

import os
import requests

key = os.environ["SUME_API_KEY"]
url = "https://api.sume.com/v1/images/models/black-forest-labs/flux.2-pro/endpoints"
resp = requests.get(url, headers={"Authorization": f"Bearer {key}"}, timeout=30)
resp.raise_for_status()
body = resp.json()
body = body.get("data", body)
for endpoint in body["endpoints"]:
    for line in endpoint["pricing"]:
        print(endpoint["provider_slug"], line["billable"], line["unit"], line["cost_usd"])

Limits

fal's formula is fal's. Do not assume Sume bills input megapixels or accepts 9 references; the input_references range in the catalog and the pricing lines are the source. Send a real call and read usage.cost once before scaling.