Flux Fill Pro API

Inpaint with a mask or outpaint to extend the canvas.

Integrate Flux Fill Pro with a single API call — one key, one unified endpoint, and shared billing across every model on Apiframe.

Get API Key View Docs

model: "flux-fill-pro"

What's special about Flux Fill Pro

Image-to-image editing and reference-image support.
Fast turnaround — about 15s per generation on average.
Pay-as-you-go pricing with no Black Forest Labs account required — you only pay for successful generations.
One API key, unified billing, idempotency and webhooks across every Apiframe model.

Made with Flux Fill Pro

A few outputs generated through the Flux Fill Pro API on Apiframe.

Sample coming soon

Overview

Endpoint: POST /v2/images/edit
Model ID: flux-fill-pro
Params key: fluxFillParams
Modality: image
Provider: Black Forest Labs
Pricing: Pay-as-you-go
Avg. completion: ~15s

Capabilities

Image inputSupported

Avg. time~15s

Quick start

Send a single POST /v2/images/edit request with your API key to generate with Flux Fill Pro. The call returns a jobId you can poll or receive via webhook.

curl -X POST https://api.apiframe.ai/v2/images/edit \
  -H "X-API-Key: afk_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
        "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
        "model": "flux-fill-pro",
        "fluxFillParams": {
            "image": "https://example.com/input.jpg",
            "mode": "inpaint",
            "mask": "https://example.com/input.jpg",
            "outpaint": "Zoom out 1.5x"
        }
    }'

import requests

response = requests.post(
    "https://api.apiframe.ai/v2/images/edit",
    headers={
        "X-API-Key": "afk_your_api_key_here",
        "Content-Type": "application/json",
    },
    json={
        "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
        "model": "flux-fill-pro",
        "fluxFillParams": {
            "image": "https://example.com/input.jpg",
            "mode": "inpaint",
            "mask": "https://example.com/input.jpg",
            "outpaint": "Zoom out 1.5x"
        }
    },
)
print(response.json())  # { "jobId": "...", "status": "QUEUED" }

const response = await fetch("https://api.apiframe.ai/v2/images/edit", {
  method: "POST",
  headers: {
    "X-API-Key": "afk_your_api_key_here",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "prompt": "a sleek silver sports car on a coastal highway at sunset, hyper-realistic",
    "model": "flux-fill-pro",
    "fluxFillParams": {
      "image": "https://example.com/input.jpg",
      "mode": "inpaint",
      "mask": "https://example.com/input.jpg",
      "outpaint": "Zoom out 1.5x"
    }
  }),
});
const { jobId } = await response.json();
console.log(jobId);

Response & job lifecycle

Generation is asynchronous. A successful submission returns 202 Accepted with a jobId. Poll GET /v2/jobs/{id} (or supply a webhook_url) until the status is COMPLETED; the result field then holds the output URL(s).

1. Submission response (202)

{
  "jobId": "b2c3d4e5-f6a7-8901-bcde-f23456789012",
  "status": "QUEUED"
}

2. Poll for the result

curl https://api.apiframe.ai/v2/jobs/JOB_ID \
  -H "X-API-Key: afk_your_api_key_here"

import requests, time

while True:
    job = requests.get(
        "https://api.apiframe.ai/v2/jobs/JOB_ID",
        headers={"X-API-Key": "afk_your_api_key_here"},
    ).json()
    if job["status"] in ("COMPLETED", "FAILED"):
        break
    time.sleep(2)
print(job["result"])

let job;
do {
  await new Promise((r) => setTimeout(r, 2000));
  job = await fetch("https://api.apiframe.ai/v2/jobs/JOB_ID", {
    headers: { "X-API-Key": "afk_your_api_key_here" },
  }).then((r) => r.json());
} while (job.status !== "COMPLETED" && job.status !== "FAILED");
console.log(job.result);

Input schema

Request parameters accepted by the Flux Fill Pro endpoint. Model-specific options are nested under the params object shown below.

Parameter	Type	Required	Default	Allowed / range	Description
prompt	string	required	—	—	Text description of what to generate.
model	string	required	"flux-fill-pro"	"flux-fill-pro"	The model identifier for this endpoint.
fluxFillParams.image	string (URL)	optional	—	—	Source image (URL)
fluxFillParams.mode	string	optional	"inpaint"	"inpaint", "outpaint"	Mode
fluxFillParams.mask	string (URL)	optional	—	—	White = repaint, black = keep. Required for inpaint.
fluxFillParams.outpaint	string	optional	"Zoom out 1.5x"	"Zoom out 1.5x", "Zoom out 2x", "Make square", "Left outpaint", "Right outpaint", "Top outpaint", "Bottom outpaint"	Required for outpaint mode.
fluxFillParams.prompt	string	optional	—	—	Prompt
fluxFillParams.prompt_upsampling	boolean	optional	false	—	Prompt upsampling
fluxFillParams.steps	number	optional	50	min 1, max 50, step 1	Steps
fluxFillParams.guidance	number	optional	3	min 2, max 5, step 0.1	Guidance
fluxFillParams.safety_tolerance	number	optional	2	min 1, max 6, step 1	1 = strictest, 6 = most permissive.
fluxFillParams.output_format	string	optional	"jpg"	"jpg", "png"	Output format
fluxFillParams.seed	number	optional	—	step 1	Reuse a number to reproduce the same result.

Frequently Asked Questions

Common questions about the Flux Fill Pro API.

Is there an API for Flux Fill Pro?

Yes. Apiframe exposes Flux Fill Pro through a single REST endpoint (`POST /v2/images/edit` with `model: "flux-fill-pro"`). You get one unified API, key, and billing across every supported model — no separate Black Forest Labs account required.

How much does the Flux Fill Pro API cost?

Flux Fill Pro uses simple pay-as-you-go pricing on Apiframe — you only pay for successful generations. See the pricing page for plans and volume discounts.

How do I call the Flux Fill Pro API?

Send a POST request to `/v2/images/edit` with your `X-API-Key` and a JSON body containing `model: "flux-fill-pro"`. The call returns a `jobId`; poll `GET /v2/jobs/{id}` or use a webhook to receive the result.

What parameters does Flux Fill Pro support?

Flux Fill Pro accepts 11 model-specific parameters (nested under `fluxFillParams`) plus the common `prompt` and `webhook_url` fields. See the input schema above for the full list with types and defaults.

Still have questions?

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Start building with the Flux Fill Pro API

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