Flux Kontext Pro Multi API Documentation

Flux Kontext Pro Multi API Documentation

Playground

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Experimental FLUX.1 Kontext [pro] with multi-image handling to combine context from multiple images for richer output. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

FLUX Kontext Pro Multi is a fast, reliable multi-image model for context-guided generation and editing. Provide a text prompt plus up to 5 reference images, and the model uses them to improve identity consistency, style alignment, and scene coherence—ideal for practical production workflows that need strong control at a lower cost.

Key capabilities

  • Multi-image contextual generation with up to 5 reference images
  • Strong identity and style consistency by grounding outputs in references
  • Reliable composition control for everyday creative and marketing use
  • Efficient for iterative workflows and rapid A/B exploration

Typical use cases

  • Character consistency using multiple portraits, outfits, or angles
  • Product and branding consistency (packaging + logo + lighting references)
  • Style steering with multiple exemplars (art style + texture + mood)
  • Scene creation guided by reference frames
  • Marketing creatives that need predictable, repeatable visual direction

Pricing

$0.04 per image.

Total cost = num_images × $0.04 Example: num_images = 4 → $0.16

Inputs and outputs

Input:

  • prompt (required): Instruction describing what to generate and how to use the references
  • images (required): Up to 5 reference images (upload or public URLs)

Output:

  • One or more generated images (based on your num_images setting, if available in your interface)

Parameters

  • prompt (required): The instruction for generation or editing
  • images (required): Up to 5 reference images
  • seed: Fixed value for reproducibility; leave empty/random for variation
  • guidance_scale: Prompt adherence strength (higher = stricter; too high may over-constrain)
  • aspect_ratio: Output aspect ratio (e.g., 16:9, 1:1, 9:16)

Prompting guide (multi-reference)

Assign roles to references to reduce ambiguity:

Template: Use image 1 for identity. Use image 2 for outfit/material. Use image 3 for style. Use image 4 for lighting. Use image 5 for background/scene. Generate the shot described below. Keep the key traits unchanged.

Example prompts

  • Use image 1 for the person’s identity and image 2 for outfit details. Use image 3 for visual style. Create a 16:9 cinematic medium shot in a rainy city street at night. Match lighting and reflections. Keep face structure and expression consistent.
  • Use image 1 for the product shape and image 2 for label layout. Use image 3 for lighting mood. Generate a clean studio product shot with realistic shadows and crisp edges. Keep branding placement consistent.
  • Use images 1–2 as identity references from different angles. Create a neutral-background portrait with softbox lighting and natural skin texture. Keep proportions realistic and avoid exaggerated stylization.

Best practices

  • Use high-quality references (sharp, well-lit, minimal occlusion)
  • Avoid conflicting references unless you explicitly state which reference dominates (identity vs. style vs. scene)
  • Keep guidance_scale moderate and let references do most of the steering
  • Fix seed when you need stable iteration and consistent comparisons
  • Choose aspect_ratio intentionally to avoid awkward cropping or stretched composition

Authentication

For authentication details, please refer to the Authentication Guide.

API Endpoints

Submit Task & Query Result

set -euo pipefail

export WAVESPEED_API_KEY="your-api-key"

REQUEST_BODY=$(cat <<'JSON'
{
  "prompt": "A cinematic ocean wave at sunrise, highly detailed",
  "images": [
    "https://interactive-examples.mdn.mozilla.net/media/cc0-images/painted-hand-298-332.jpg"
  ],
  "guidance_scale": 3.5,
  "aspect_ratio": "21:9"
}
JSON
)

# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  -X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-kontext-pro/multi" \
  -H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  -H "Content-Type: application/json" \
  -d "${REQUEST_BODY}")

TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
  printf 'Submission response did not contain a prediction id
' >&2
  exit 1
fi
RESULT_URL=$(printf '%s' "${TASK}" | jq -r '.urls.get // empty')
if [ -z "${RESULT_URL}" ]; then RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"; fi

# 2. Poll until the prediction finishes.
while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body \
    "${RESULT_URL}" \
    -H "Authorization: Bearer ${WAVESPEED_API_KEY}")
  RESULT=$(printf '%s' "${RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
  STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')

  case "${STATUS}" in
    completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
    failed|cancelled|timeout) printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
    created|processing) sleep 2 ;;
    *) printf 'Unexpected status: %s
' "${STATUS}" >&2; exit 1 ;;
  esac
done

Parameters

Task Submission Parameters

Request Parameters

ParameterTypeRequiredDefaultRangeDescription
promptstringYes-The positive prompt for the generation.
imagesarray<string>Yes-0 ~ 5 itemsURL of images to use while generating the image.
seedintegerNo--The random seed to use for the generation.
guidance_scalenumberNo3.51 ~ 20The guidance scale to use for the generation.
aspect_ratiovalueNo-21:9, 16:9, 4:3, 3:2, 1:1, 2:3, 3:4, 9:16, 9:21The aspect ratio of the generated media.
enable_sync_modebooleanNofalse-If set to `true`, the request attempts to wait for the generated result and return outputs in the same response. If the result is not ready within the sync wait window, the API can return a timeout body while the task continues processing. This option is only available via the API and is supported only by some models.

Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
data.idstringUnique identifier for the prediction, Task Id
data.modelstringModel ID used for the prediction
data.outputsarrayOutput values, usually URL strings; some models return text strings or structured result objects (empty when status is not completed)
data.urlsobjectObject containing related API endpoints
data.urls.getstringURL to retrieve the prediction result
data.statusstringStatus of the task: created, processing, completed, or failed
data.created_atstringISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”)
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds

Result Request Parameters

ParameterTypeRequiredDefaultDescription
idstringYes-Task ID

Result Response Parameters

ParameterTypeDescription
codeintegerHTTP status code (e.g., 200 for success)
messagestringStatus message (e.g., “success”)
dataobjectThe prediction data object containing all details
data.idstringUnique identifier for the prediction
data.modelstringModel ID used for the prediction
data.outputsarray<string | object>Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model.
data.urlsobjectObject containing related API endpoints
data.urls.getstringURL to poll for the prediction result
data.statusstringStatus: created, processing, completed, or failed
data.created_atstringISO timestamp of when the request was created
data.errorstringError message (empty if no error occurred)
data.timingsobjectObject containing timing details
data.timings.inferenceintegerInference time in milliseconds
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