Flux.1 Schnell Serverless API

Flux Schnell  is a state-of-the-art text-to-image generation model engineered for speed and efficiency.

~10.04s
POST /v2/flux-schnell · 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-schnell",
 9    prompt="a bengal tiger in an astronaut suit on mars, cubist style holding a sign saying 'awesome text gen'",
10    steps=4,
11    seed=123456789,
12    sampler_name="euler",
13    scheduler="normal",
14    samples=1,
15    width=1024,
16    height=1024,
17    denoise=1,
18)
19print(result["status"])                      # COMPLETED
20print(result.get("output"))                  # model output (e.g. media URL)
21print(result["metrics"]["inference_time"])   # server compute seconds
22
23# --- Or submit + poll manually (track request_id, control the cadence) ---
24from segmind import SegmindClient, InferenceFailed, InferenceTimeout
25
26client = SegmindClient()                      # reads SEGMIND_API_KEY
27payload = {
28    "prompt": "a bengal tiger in an astronaut suit on mars, cubist style holding a sign saying 'awesome text gen'",
29    "steps": 4,
30    "seed": 123456789,
31    "sampler_name": "euler",
32    "scheduler": "normal",
33    "samples": 1,
34    "width": 1024,
35    "height": 1024,
36    "denoise": 1,
37}
38job = client.submit_async("flux-schnell", **payload)
39print(job.request_id)                         # available immediately
40try:
41    result = job.wait(timeout=600, interval=1.0)
42except InferenceTimeout as e:
43    print("still running:", e.request_id)
44except InferenceFailed as e:
45    print("failed:", e.detail)

API Endpoint

POSThttps://api.segmind.com/v1/flux-schnell

Parameters

promptrequired
string

Text prompt for generating the image

Default: "a bengal tiger in an astronaut suit on mars, cubist style holding a sign saying 'awesome text gen'"
denoiseoptional
number

Denoise level for the generated image

Default: 1Range: 0 - 1
heightoptional
integer

Image height can be between 128 and 2048 in multiples of 64

Default: 1024
sampler_nameoptional
string

Sampler for the image generation process

Default: "euler"
Allowed values (27 total):
"euler""euler_pp""euler_ancestral""euler_ancestral_pp""heun""heunpp2""dpm_2""dpm_2_ancestral""lms""dpm_fast"+17 more
samplesoptional
integer

Number of samples to generate

Default: 1
scheduleroptional
string

Scheduler for the image generation process

Default: "normal"
Allowed values :
"normal""karras""exponential""sgm_uniform""simple""ddim_uniform"
seedoptional
integer

Seed for random number generation

Default: 123456789
stepsoptional
integer

Number of inference steps for image generation

Default: 4Range: 1 - 8
widthoptional
integer

Image width can be between 128 and 2048 in multiples of 64

Default: 1024

Response Type

Returns: Text/JSON

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-schnell

    Submitreturns request_id, status_url, response_url

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

    Polluntil COMPLETED or FAILED

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

    Resultfinal response body

Status states

QUEUEDAccepted, waiting for a worker
PROCESSINGRunning on a worker
COMPLETEDDone — result body is ready
FAILEDErrored (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