Flux Kontext Dev Free: AI Image Generator & Editor
Edit images via text with layered control, style and object memory, and iterative consistency for accurate, research-friendly creative workflows.
Table of contents
1. Get started
Use RunComfy's API to run blackforestlabs/flux-1-kontext/dev/image-to-image. For accepted inputs and outputs, see the model's schema.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-1-kontext/dev/image-to-image \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "Convert the scene to blue hour with soft drizzle; preserve subject identity and framing; add gentle rim light and puddle reflections; subtle neon signage in the distance for cinematic depth",
"image_url": "https://playgrounds-storage-public.runcomfy.net/tools/7007/media-files/usecase2-2-input.png"
}'2. Authentication
Set the YOUR_API_TOKEN environment variable with your API key (manage keys in your Profile) and include it on every request as a Bearer token via the Authorization header: Authorization: Bearer $YOUR_API_TOKEN.
3. API reference
Submit a request
Submit an asynchronous generation job and immediately receive a request_id plus URLs to check status, fetch results, and cancel.
curl --request POST \
--url https://model-api.runcomfy.net/v1/models/blackforestlabs/flux-1-kontext/dev/image-to-image \
--header "Content-Type: application/json" \
--header "Authorization: Bearer <token>" \
--data '{
"prompt": "Convert the scene to blue hour with soft drizzle; preserve subject identity and framing; add gentle rim light and puddle reflections; subtle neon signage in the distance for cinematic depth",
"image_url": "https://playgrounds-storage-public.runcomfy.net/tools/7007/media-files/usecase2-2-input.png"
}'Monitor request status
Fetch the current state for a request_id ("in_queue", "in_progress", "completed", or "cancelled").
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/status \
--header "Authorization: Bearer <token>"Retrieve request results
Retrieve the final outputs and metadata for the given request_id; if the job is not complete, the response returns the current state so you can continue polling.
curl --request GET \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/result \
--header "Authorization: Bearer <token>"Cancel a request
Cancel a queued job by request_id, in-progress jobs cannot be cancelled.
curl --request POST \
--url https://model-api.runcomfy.net/v1/requests/{request_id}/cancel \
--header "Authorization: Bearer <token>"4. File inputs
Hosted file (URL)
Provide a publicly reachable HTTPS URL. Ensure the host allows server‑side fetches (no login/cookies required) and isn't rate‑limited or blocking bots. Recommended limits: images ≤ 50 MB (~4K), videos ≤ 100 MB (~2–5 min @ 720p). Prefer stable or pre‑signed URLs for private assets.
5. Schema
Input schema
{
"type": "object",
"title": "Input",
"required": [
"prompt",
"image_url"
],
"properties": {
"prompt": {
"title": "Prompt",
"description": "",
"type": "string",
"default": "Convert the scene to blue hour with soft drizzle; preserve subject identity and framing; add gentle rim light and puddle reflections; subtle neon signage in the distance for cinematic depth"
},
"image_url": {
"title": "Image",
"description": "",
"type": "string",
"default": "https://playgrounds-storage-public.runcomfy.net/tools/7007/media-files/usecase2-2-input.png"
},
"num_inference_steps": {
"title": "Num Inference Steps",
"description": "The number of inference steps to perform. ",
"type": "integer",
"maximum": 50,
"minimum": 10,
"default": 28
},
"seed": {
"title": "Seed",
"description": "",
"type": "integer",
"default": 56941555
}
}
}Output schema
{
"output": {
"type": "object",
"properties": {
"image": {
"type": "string",
"format": "uri",
"description": "single image URL"
},
"video": {
"type": "string",
"format": "uri",
"description": "single video URL"
},
"images": {
"type": "array",
"description": "multiple image URLs",
"items": { "type": "string", "format": "uri" }
},
"videos": {
"type": "array",
"description": "multiple video URLs",
"items": { "type": "string", "format": "uri" }
}
}
}
}RunComfy is the premier ComfyUI platform, offering ComfyUI online environment and services, along with ComfyUI workflows featuring stunning visuals. RunComfy also provides AI Models, enabling artists to harness the latest AI tools to create incredible art.