Flux Fill Dev Serverless API

Open-weight inpainting model for editing and extending images. Guidance-distilled from FLUX.1 Fill Dev

~16.51s
PlaygroundAPI
Pricing
POST /v2/flux-fill-dev · submit + poll
 1# pip install "segmind>=1.1.0"
 2# export SEGMIND_API_KEY="YOUR_API_KEY"
 3import segmind
 4
 5# Async (v2): submit to the queue and block until COMPLETED.
 6# run() returns the final result dict (600s deadline, 1.0s poll by default).
 7result = segmind.run(
 8    "flux-fill-dev",
 9    mask="https://segmind-sd-models.s3.us-east-1.amazonaws.com/display_images/flux-tools/flux-fill-dev-mask.png",
10    seed=985266,
11    image="https://segmind-sd-models.s3.us-east-1.amazonaws.com/display_images/flux-tools/flux-fill-dev-ip.png",
12    prompt="Green hair",
13    guidance=30,
14    megapixels="1",
15    num_outputs=1,
16    output_format="jpg",
17    output_quality=80,
18    num_inference_steps=28,
19    disable_safety_checker=False,
20)
21print(result["status"])                      # COMPLETED
22print(result.get("output"))                  # model output (e.g. media URL)
23print(result["metrics"]["inference_time"])   # server compute seconds
24
25# --- Or submit + poll manually (track request_id, control the cadence) ---
26from segmind import SegmindClient, InferenceFailed, InferenceTimeout
27
28client = SegmindClient()                      # reads SEGMIND_API_KEY
29payload = {
30    "mask": "https://segmind-sd-models.s3.us-east-1.amazonaws.com/display_images/flux-tools/flux-fill-dev-mask.png",
31    "seed": 985266,
32    "image": "https://segmind-sd-models.s3.us-east-1.amazonaws.com/display_images/flux-tools/flux-fill-dev-ip.png",
33    "prompt": "Green hair",
34    "guidance": 30,
35    "megapixels": "1",
36    "num_outputs": 1,
37    "output_format": "jpg",
38    "output_quality": 80,
39    "num_inference_steps": 28,
40    "disable_safety_checker": False,
41}
42job = client.submit_async("flux-fill-dev", **payload)
43print(job.request_id)                         # available immediately
44try:
45    result = job.wait(timeout=600, interval=1.0)
46except InferenceTimeout as e:
47    print("still running:", e.request_id)
48except InferenceFailed as e:
49    print("failed:", e.detail)

API Endpoint

POSThttps://api.segmind.com/v1/flux-fill-dev

Parameters

imagerequired
string (uri)

The image to inpaint. Can contain alpha mask. If the image width or height are not multiples of 32, they will be scaled to the closest multiple of 32. If the image dimensions don't fit within 1440x1440, it will be scaled down to fit.

Default: "https://segmind-sd-models.s3.us-east-1.amazonaws.com/display_images/flux-tools/flux-fill-dev-ip.png"
maskrequired
string (uri)

A black-and-white image that describes the part of the image to inpaint. Black areas will be preserved while white areas will be inpainted.

promptrequired
string

Prompt for generated image

Default: "Green hair"
disable_safety_checkeroptional
boolean

Disable safety checker for generated images.

Default: false
guidanceoptional
number

Guidance for generated image

Default: 30Range: 0 - 100
megapixelsoptional
string

Approximate number of megapixels for generated image. Use match_input to match the size of the input (with an upper limit of 1440x1440 pixels)

Default: "1"
Allowed values :
"1""0.25""match_input"
num_inference_stepsoptional
integer

Number of denoising steps. Recommended range is 28-50, and lower number of steps produce lower quality outputs, faster.

Default: 28Range: 1 - 50
num_outputsoptional
integer

Number of outputs to generate

Default: 1Range: 1 - 4
output_formatoptional
string

An enumeration.

Default: "jpg"
Allowed values :
"webp""jpg""png"
output_qualityoptional
integer

Quality when saving the output images, from 0 to 100. 100 is best quality, 0 is lowest quality. Not relevant for .png outputs

Default: 80Range: 0 - 100
seedoptional
integer

Random seed. Set for reproducible generation

Default: 985266

Response Type

Returns: Image

Asynchronous requests (v2)

Use Async for video, long-running (>~60s), or high-concurrency workloads; Sync is simplest for fast image & LLM calls. Async submits a request and you poll it to completion.

  1. 1
    POST /v2/flux-fill-dev

    Submit — returns request_id, status_url, response_url

  2. 2
    GET /v2/requests/{id}/status

    Poll — until COMPLETED or FAILED

  3. 3
    GET /v2/requests/{id}

    Result — final response body

Status states

QUEUED— Accepted, waiting for a worker
PROCESSING— Running on a worker
COMPLETED— Done — result body is ready
FAILED— Errored (incl. content/RAI blocks)
  • A FAILED request is served as HTTP 422 — the body still carries the error detail.
  • An unknown or expired request_id returns HTTP 404.
  • Results are retained for 1 hour, then expire.
  • Content / RAI blocks surface as FAILED, not a separate state.
  • Track completion by polling the status endpoint.

Common Error Codes

The API returns standard HTTP status codes. Detailed error messages are provided in the response body.

400

Bad Request

Invalid parameters or request format

401

Unauthorized

Missing or invalid API key

403

Forbidden

Insufficient permissions

404

Not Found

Model or endpoint not found

406

Insufficient Credits

Not enough credits to process request

429

Rate Limited

Too many requests

500

Server Error

Internal server error

502

Bad Gateway

Service temporarily unavailable

504

Timeout

Request timed out