Flux Dev Finetuned Serverless API

Flux is a 12 billion parameter rectified flow transformer capable of generating images from text descriptions

~22.15s
POST /v2/flux-dev-finetuned · 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-dev-finetuned",
 9    prompt="TOK TOK",
10    steps=25,
11    seed=6652105,
12    scheduler="simple",
13    sampler_name="euler",
14    aspect_ratio="1:1",
15    lora_strength=1,
16    hardware="cost",
17)
18print(result["status"])                      # COMPLETED
19print(result.get("output"))                  # model output (e.g. media URL)
20print(result["metrics"]["inference_time"])   # server compute seconds
21
22# --- Or submit + poll manually (track request_id, control the cadence) ---
23from segmind import SegmindClient, InferenceFailed, InferenceTimeout
24
25client = SegmindClient()                      # reads SEGMIND_API_KEY
26payload = {
27    "prompt": "TOK TOK",
28    "steps": 25,
29    "seed": 6652105,
30    "scheduler": "simple",
31    "sampler_name": "euler",
32    "aspect_ratio": "1:1",
33    "lora_strength": 1,
34    "hardware": "cost",
35}
36job = client.submit_async("flux-dev-finetuned", **payload)
37print(job.request_id)                         # available immediately
38try:
39    result = job.wait(timeout=600, interval=1.0)
40except InferenceTimeout as e:
41    print("still running:", e.request_id)
42except InferenceFailed as e:
43    print("failed:", e.detail)

API Endpoint

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

Parameters

aspect_ratiorequired
string

Aspect ratio for the generated image

Default: "1:1"
Allowed values (13 total):
"1:1""2:3""3:4""5:8""9:16""9:19""9:21""3:2""4:3""8:5"+3 more
finetune_idrequired
string

ID of the fine-tuned model you want to use.

Default: "my-finetune-id"
lora_strengthrequired
number

Strength of the LoRA (Low-Rank Adaptation) for fine-tuning

Default: 1Range: -10 - 10
promptrequired
string

Text prompt for generating the image

Default: "TOK TOK"
sampler_namerequired
string

Sampler type for image generation

Default: "euler"
Allowed values (26 total):
"euler""euler_pp""euler_ancestral""euler_ancestral_pp""heun""heunpp2""dpm_2""dpm_2_ancestral""lms""dpm_fast"+16 more
schedulerrequired
string

Scheduler type for image generation

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

Seed for random number generation

Default: 6652105
stepsrequired
integer

Number of steps for generating the image

Default: 25Range: 1 - 100
hardwareoptional
string

The hardware to use. Does not affect quality, only latency and cost

Default: "cost"
Allowed values :
"fast""cost"

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-dev-finetuned

    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