Flux.1 Schnell Serverless API

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

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

API Endpoint

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

Parameters

promptrequired
string

Describe the image to generate.

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

Image height in pixels (128-2048, snapped to the nearest multiple of 64).

Default: 1024Range: 128 - 2048
seedoptional
integer

Seed for reproducible results.

Default: 123456789Range: 0 - 999999999999999
stepsoptional
integer

Number of inference steps.

Default: 4Range: 1 - 8
widthoptional
integer

Image width in pixels (128-2048, snapped to the nearest multiple of 64).

Default: 1024Range: 128 - 2048

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