FLUX.1 Fill [dev] is a 12B-parameter rectified flow transformer for text-guided image inpainting that fills areas of existing images from text prompts. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.
Bezczynny

$0.035za uruchomienie·~28 / $1

A white translucent silk scarf is wrapped around the neck and flutters in the wind.

White rustic star necklace

A big colorful toy ball

blue triangular scarf with texture

place a cute little cat, sleeping on the sofa

Change the color to light pink clothes

Black lady's belt
FLUX Fill Dev is a powerful AI-powered inpainting model that fills in masked regions of images based on text prompts. Upload an image and mask, describe what should appear in the masked area, and the model seamlessly generates new content that blends naturally with the surrounding image.
| Parameter | Required | Description |
|---|---|---|
| image | Yes | Source image to edit (upload or public URL). |
| mask_image | Yes | Mask image (white = generate, black = preserve). |
| prompt | Yes | Text description of what to generate in the masked area. |
| width | No | Output width: 256–1536 pixels (default: 1024). |
| height | No | Output height: 256–1536 pixels (default: 1024). |
| num_inference_steps | No | Quality/speed trade-off (default: 28). |
| seed | No | Set for reproducibility (default: 0). |
| guidance_scale | No | Prompt adherence strength (default: 30). |
| num_images | No | Number of images to generate (default: 1). |
| loras | No | LoRA models to apply. Up to 3 LoRAs. |
| Output | Price |
|---|---|
| Per image | $0.035 |
Grab a WaveSpeedAI API key, then call POST https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-fill-dev with your input as JSON. The endpoint returns a prediction id. Start polling the result endpoint around every 2 seconds, increase the interval for long-running tasks, and stop on any terminal status. On completed, read URLs from data.outputs. Examples for Flux Fill Dev below.
# Submit the prediction
curl --fail-with-body --connect-timeout 10 --max-time 60 \
-X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-fill-dev" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $WAVESPEED_API_KEY" \
-d '{
"prompt": "A cinematic shot of a city at sunset, soft golden light",
"image": "https://example.com/your-input.jpg",
"size": "1024*1024",
"num_inference_steps": 28,
"seed": 0,
"guidance_scale": 30,
"num_images": 1
}'
# Wait at least 2 seconds, then poll. Safe GET requests may be retried.
curl --fail-with-body --connect-timeout 10 --max-time 30 \
--retry 4 --retry-all-errors --retry-delay 1 \
-X GET "https://api.wavespeed.ai/api/v3/predictions/{request_id}/result" \
-H "Authorization: Bearer $WAVESPEED_API_KEY"
# Start at 2 seconds and increase the interval for long-running tasks.
# Stop on completed, failed, cancelled, or timeout.// npm install wavespeed
const { Client } = require('wavespeed');
const apiKey = process.env.WAVESPEED_API_KEY;
if (!apiKey) throw new Error('Set WAVESPEED_API_KEY');
const client = new Client(apiKey);
try {
const result = await client.run("wavespeed-ai/flux-fill-dev", {
"prompt": "A cinematic shot of a city at sunset, soft golden light",
"image": "https://example.com/your-input.jpg",
"size": "1024*1024",
"num_inference_steps": 28,
"seed": 0,
"guidance_scale": 30,
"num_images": 1
}, {
timeout: 3600,
pollInterval: 2.0,
});
console.log(result.outputs);
} catch (error) {
console.error('Generation failed:', error);
process.exitCode = 1;
}# pip install wavespeed
import os
from wavespeed import Client
client = Client(api_key=os.environ["WAVESPEED_API_KEY"])
try:
output = client.run(
"wavespeed-ai/flux-fill-dev",
{
"prompt": "A cinematic shot of a city at sunset, soft golden light",
"image": "https://example.com/your-input.jpg",
"size": "1024*1024",
"num_inference_steps": 28,
"seed": 0,
"guidance_scale": 30,
"num_images": 1
},
timeout=3600.0,
poll_interval=2.0,
)
print(output["outputs"])
except Exception as error:
raise SystemExit(f"Generation failed: {error}") from errorFlux Fill Dev is a WaveSpeedAI model for image editing, exposed as a REST API on WaveSpeedAI. FLUX.1 Fill [dev] is a 12B-parameter rectified flow transformer for text-guided image inpainting that fills areas of existing images from text prompts. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing. You can call it programmatically or try it from the playground above.
POST your input parameters to the model's REST endpoint (shown in the API tab of this playground) with your WaveSpeedAI API key in the Authorization header. Submission returns a prediction ID. Poll the result endpoint starting around every 2 seconds, increase the interval for long-running tasks, and stop on any terminal status. The playground generates production-oriented Python, JavaScript, and cURL examples with timeouts, transient-error handling, and safe GET retries. Full request/response shape is documented at https://wavespeed.ai/docs/docs-api/wavespeed-ai/flux-fill-dev.
Flux Fill Dev starts at $0.035 per run. That figure is the base price — the final charge scales with the parameters you set in the form (output size, length, count, references, or whatever knobs this model exposes), so a higher-quality or larger output costs more than a minimal one. The exact cost for your current input is shown live next to the Generate button before you submit, and the actual per-call charge is recorded on the prediction afterwards.
Key inputs: `prompt`, `image`, `size`, `seed`, `guidance_scale`, `num_inference_steps`. The full JSON schema (types, defaults, allowed values) is rendered above the Generate button and mirrored in the API reference at https://wavespeed.ai/docs/docs-api/wavespeed-ai/flux-fill-dev.
Average end-to-end generation time on WaveSpeedAI is around 14 seconds per request — measured across recent runs. Queue time scales with global demand; live status is visible in the prediction record.
Commercial usage rights depend on the model's license, set by its provider (WaveSpeedAI). The license summary appears on the model card above; see WaveSpeedAI's Terms of Service for platform-level conditions.