Fast Flux.1 Schnell Serverless API

Fast Flux.1 Schnell by Segmind is an optimized text-to-image model designed for developers needing faster image generation. It offers high efficiency without compromising quality. Perfect for startups and engineers seeking quick, resource-efficient AI models.

POST /v2/fast-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    "fast-flux-schnell",
 9    prompt="A wallpaper image of sports car with 'Flux' written on it, motion blur, side view, long shot",
10    steps=4,
11    seed=1184522,
12    aspect_ratio="1:1",
13    base64=False,
14)
15print(result["status"])                      # COMPLETED
16print(result.get("output"))                  # model output (e.g. media URL)
17print(result["metrics"]["inference_time"])   # server compute seconds
18
19# --- Or submit + poll manually (track request_id, control the cadence) ---
20from segmind import SegmindClient, InferenceFailed, InferenceTimeout
21
22client = SegmindClient()                      # reads SEGMIND_API_KEY
23payload = {
24    "prompt": "A wallpaper image of sports car with 'Flux' written on it, motion blur, side view, long shot",
25    "steps": 4,
26    "seed": 1184522,
27    "aspect_ratio": "1:1",
28    "base64": False,
29}
30job = client.submit_async("fast-flux-schnell", **payload)
31print(job.request_id)                         # available immediately
32try:
33    result = job.wait(timeout=600, interval=1.0)
34except InferenceTimeout as e:
35    print("still running:", e.request_id)
36except InferenceFailed as e:
37    print("failed:", e.detail)

API Endpoint

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

Parameters

promptrequired
string

Text prompt for generating the image

Default: "A wallpaper image of sports car with 'Flux' written on it, motion blur, side view, long shot"
aspect_ratiooptional
string

aspect ratio of the output image

Default: "1:1"
Allowed values :
"1:1""16:9""21:9""2:3""3:2""4:5""5:4""9:16""9:21"
base64optional
boolean

Base64 encoding of the output image.

Default: false
seedoptional
integer

Seed for random number generation

Default: 1184522
stepsoptional
integer

Number of inference steps for image generation

Default: 4Range: 1 - 8

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/fast-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