FLUX.1 Fill Dev LoRA API

About FLUX.1 Fill Dev LoRA

FLUX.1 Fill Dev LoRA runs Black Forest Labs' FLUX.1 Fill [dev], a 12-billion-parameter model trained for inpainting, with up to three LoRA files trained for FLUX.1 dev. Send a source image and a black-and-white mask: only the white area is redrawn to match your prompt, the rest comes back untouched, and nothing is filtered.

Call it with the model name black-forest-labs/flux-1-fill-dev-lora/edit on POST /jobs/createTask, from 7 credits per image ($0.07). New accounts get 30 free credits to try it in the Playground first.

Introduction

FLUX.1 Fill Dev LoRA Inpainting redraws the masked part of one image with FLUX.1 Fill [dev], the 12-billion-parameter fill model from Black Forest Labs, with up to three of your own LoRA files loaded. White in the mask is repainted to match your prompt; black is returned as it was.

Key features

The rest of the picture stays

In our tests the unmasked area came back untouched and an all-black mask returned the photo unchanged, so a face, a room or a product shot survives the edit.

Fills that match the light

The model was trained to blend into its surroundings: a silk dress picked up the tungsten light of an atelier and a hoodie the low sun of a studio without any extra prompting.

Your own LoRAs inside the mask

Up to three FLUX.1 dev LoRAs load per request.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

Each task is rounded up to whole credits, so one run at the lowest tier costs 7 credits per image ($0.07).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Fashion and wardrobe changes

Change a garment, a colour or a neckline on a finished photo while the model, pose and set stay exactly as shot.

Retouching

Repaint a hand, remove an object or replace a background element by masking only that region.

Art inside a scene

Mask a wall, a canvas or a sheet of paper and paint a mural or sketch onto it with a style LoRA.

Prompt guide & pro tips

Describe the white area

You do not need to re-describe the rest of the photo.

Mask generously

Whatever is left outside the mask stays in the picture.

Keep the mask on the source canvas

Export the mask at the same size as the photo. A mask of another size is stretched, which moves the white area.

Ask for several takes

Fills vary with the seed. Two to four images per run is the quickest way to a clean edge.

API quick start

Call the FLUX.1 Fill Dev LoRA API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model black-forest-labs/flux-1-fill-dev-lora/edit and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "black-forest-labs/flux-1-fill-dev-lora/edit",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "image_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "mask_url": "https://media.popnow.ai/influencer/examples/marco.webp",
    "resolution": "1k",
    "num_outputs": 1
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

FLUX.1 Fill Dev LoRA API questions

All FLUX models

FLUX.1 Schnell LoRA also inpaints with a mask, faster and cheaper.

• FLUX.2 Max APITop-tier FLUX: photoreal light and exact brand colorsFrom 11 credits per image
• FLUX 3 APIVideo with synced sound and a quick draft tierFrom 45 credits for a 5-second clip
• FLUX.2 Klein 9B LoRA APIFast FLUX.2 Klein 9B that loads up to three of your LoRAsFrom 3 credits per image
• FLUX.2 Klein Base 9B LoRA APIUndistilled Klein 9B for varied looks with your LoRAsFrom 4 credits per image
• FLUX.2 Klein 4B LoRA APISmall, quick FLUX.2 Klein 4B with your own LoRAsFrom 3 credits per image
• FLUX.2 Klein Base 4B LoRA APIUndistilled Klein 4B that loads your own LoRAsFrom 3 credits per image
• FLUX.2 Klein 9B APIFast FLUX edits that keep faces and poses intactFrom 2 credits per image
• FLUX.2 Klein 4B APIThe smallest, quickest FLUX for rapid draftsFrom 2 credits per image
• FLUX.2 Dev LoRA APIFLUX.2 Dev images and edits with your own LoRAsFrom 4 credits per image
• FLUX.2 Pro APIPhotoreal images with readable text and hex color controlFrom 5 credits per image
• FLUX.2 Flex APISpells headlines and labels exactly as writtenFrom 9 credits per image
• FLUX.2 Dev APIOpen-weights FLUX that can merge people into one sceneFrom 2 credits per image
• FLUX.1 Krea Dev LoRA APIPhotographic FLUX.1 Krea with your own LoRAsFrom 4 credits per image
• FLUX.1 Dev ControlNet LoRA APIPose, depth or edge control on FLUX.1 with your LoRAsFrom 6 credits per image
• FLUX.1 Fill Dev LoRA APIMasked inpainting on FLUX.1 Fill with your own LoRAsFrom 7 credits per image
• FLUX.1 Dev LoRA APIClassic FLUX.1 Dev with up to three of your LoRAsFrom 3 credits per image
• FLUX.1 Schnell LoRA APIFast FLUX.1 Schnell that loads your own LoRAsFrom 1 credit per image

Other image APIs

• Qwen Image 2.1 LoRA APIQwen Image 2.1 images and edits with up to three of your LoRAsFrom 5 credits per image
• MiniMax H3 Image LoRA APIH3 stills and edits with up to three of your LoRAsFrom 7 credits per image
• Anima Turbo LoRA APIAnime art with your own style or character LoRAsFrom 3 credits per image
• Krea 2 Turbo LoRA APIKrea 2 Turbo images and restyles with your own LoRAsFrom 4 credits per image
• P-Image LoRA APIFast P-Image renders and edits with one LoRA of your ownFrom 1 credit per image
• Z-Image Base LoRA APIZ-Image Base with up to three of your own LoRAsFrom 3 credits per image

More about FLUX.1 Fill Dev LoRA

Try it

FLUX.1 Fill Dev LoRA AI Image Editor onlineCreate images with FLUX.1 Fill Dev LoRA in PopNow

Docs

FLUX.1 Fill Dev LoRA model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage generation guide for the PopNow APIWebhooks: get FLUX.1 Fill Dev LoRA results without polling