Qwen image generation

Qwen is Alibaba's image-generation family. The orchestrator exposes two invocation paths, covering different versions of the model family:

`engine`	Model	Best for	Notes
`sdcpp` (ecosystem `qwen`)	`20b`	Default — Qwen-Image 20B on Civitai workers	`createImage` / `createVariant` / `editImage`. Version picker (`latest`, `2509`, `2512`, `2511`). LoRA support.
`fal`	`qwen2`	When you need FAL-hosted inference — including the Pro tier	`createImage` / `proCreateImage` / `editImage` / `proEditImage`. `imageSize` enum instead of width/height. No LoRA support.

Default choice for new integrations: engine: "sdcpp", ecosystem: "qwen", model: "20b". Reach for the fal path when you specifically want FAL's hosting or the Pro tier.

Prerequisites

A Civitai orchestration token (Quick start → Prerequisites)
For editImage / createVariant: one or more source image URLs, data URLs, or Base64 strings

sdcpp — Qwen-Image 20B (default path)

Text-to-image (`createImage`)

http

POST https://orchestration.civitai.com/v2/consumer/workflows?wait=60
Authorization: Bearer <your-token>
Content-Type: application/json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "sdcpp",
      "ecosystem": "qwen",
      "model": "20b",
      "operation": "createImage",
      "version": "latest",
      "prompt": "A photorealistic portrait of a woman with flowers in her hair, golden hour lighting, highly detailed",
      "width": 1024,
      "height": 1024,
      "cfgScale": 2.5,
      "steps": 20
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Common sdcpp-qwen parameters:

Field	Default	Range	Notes
`model`	— ✅	`20b`	Currently only `20b` is exposed.
`version`	`latest`	`latest` / `2509` / `2512` (create + variant) / `2511` (edit)	Model release snapshot. `latest` follows whichever is current.
`prompt`	— ✅	≤ 10 000 chars	Natural-language works well on Qwen.
`negativePrompt`	(none)	≤ 10 000 chars	Optional.
`width` / `height`	`1024`	`64`–`2048`, divisible by 8	Qwen-Image 20B is trained at 1024². Well-behaved aspect ratios stay near that pixel count. On `editImage` / `createVariant`, width/height are inferred from the source image if omitted; you may still supply them explicitly.
`cfgScale`	`2.5`	`0`–`30`	Lower than most image models — `2`–`4` is the sweet spot.
`steps`	`20`	`1`–`150`	`20`–`30` typical.
`sampleMethod`	`euler`	enum	`SdCppSampleMethod`.
`schedule`	`simple`	enum	`SdCppSchedule`.
`loras`	`{}`	`{ airUrn: strength }`	Stack multiple; `0.6`–`1.0` strengths typical.
`quantity`	`1`	`1`–`12`	Number of images per call.
`seed`	random	int64	Pin for reproducibility.

Picking a `version`

`version`	Available on	Notes
`latest`	all ops	Follows whatever release Civitai is currently pinning to. Recommended unless you need reproducibility against a specific release.
`2509`	all ops	September 2025 release snapshot.
`2512`	create / variant	December 2025 release — latest generation-side release at the time of writing.
`2511`	edit	November 2025 release — edit-specific snapshot.

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "sdcpp",
      "ecosystem": "qwen",
      "model": "20b",
      "operation": "createImage",
      "version": "2512",
      "prompt": "A majestic mountain landscape at sunrise, cinematic composition",
      "width": 1024,
      "height": 1024,
      "cfgScale": 2.5,
      "steps": 20
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Pin to a specific version when you need reproducible output or are comparing generations across a larger experiment; stick to latest for day-to-day use.

With LoRAs

LoRAs are a map of AIR URN → strength:

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "sdcpp",
      "ecosystem": "qwen",
      "model": "20b",
      "operation": "createImage",
      "prompt": "A detailed anime character in a magical forest, ethereal lighting",
      "width": 1024,
      "height": 1024,
      "cfgScale": 2.5,
      "steps": 20,
      "loras": {
        "urn:air:qwen:lora:civitai:123456@789012": 0.8
      }
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Only Qwen-tagged LoRAs work on the qwen ecosystem. Browse the Civitai Qwen LoRA catalog for AIR URNs.

Image-to-image (`createVariant`)

Pass a single source image and a prompt; the model re-imagines it. strength controls how much of the source to preserve — 0.0 returns the source unchanged, 1.0 discards it entirely. Width and height are inferred from the source.

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "sdcpp",
      "ecosystem": "qwen",
      "model": "20b",
      "operation": "createVariant",
      "prompt": "Turn it into a winter scene with snow falling",
      "image": "https://image.civitai.com/.../source.jpeg",
      "strength": 0.7
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Note image is a plain string URL (not a { url: ... } wrapper), and the field is strength (default 0.7).

Edit image (`editImage`)

Pass up to 10 reference images via images[] — Qwen-Image's edit variant accepts more sources than most edit pipelines:

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "sdcpp",
      "ecosystem": "qwen",
      "model": "20b",
      "operation": "editImage",
      "prompt": "Add a rainbow in the sky",
      "images": [
        "https://image.civitai.com/.../source.jpeg"
      ]
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Width/height are inferred from the source image(s) when omitted.

fal — FAL-hosted Qwen2 (with Pro tier)

When you want FAL's hosted inference — including the commercial Pro tier via the proCreateImage and proEditImage operations — use engine: "fal", model: "qwen2":

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "fal",
      "model": "qwen2",
      "operation": "createImage",
      "prompt": "A photorealistic portrait of a woman with flowers in her hair, golden hour lighting",
      "imageSize": "square_hd"
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

FAL-specific parameters

Field	Default	Range	Notes
`prompt`	— ✅	≥ 1 char	Natural-language works well on Qwen.
`negativePrompt`	(none)	≤ 500 chars	Much tighter limit than sdcpp's 10 000.
`imageSize`	`square_hd`	`square_hd` / `square` / `portrait_4_3` / `portrait_16_9` / `landscape_4_3` / `landscape_16_9`	Enum, not width/height. FAL doesn't accept arbitrary dimensions on Qwen2.
`quantity`	`1`	`1`–`10`	Slightly lower ceiling than sdcpp's 12.
`enablePromptExpansion`	`true`	boolean	Model-side prompt expansion — Qwen rewrites your prompt before generation. On by default.
`enableSafetyChecker`	`false`	boolean	FAL's safety filter. Off by default.
`seed`	random	int32	Pin for reproducibility.

FAL Qwen2 does not support LoRAs or uCache — use the sdcpp path when you need either.

Pro tier (`proCreateImage` / `proEditImage`)

FAL ships a Pro tier with the same input shape but routes to a higher-quality backing model. Swap the operation to proCreateImage for text-to-image or proEditImage for editing:

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "fal",
      "model": "qwen2",
      "operation": "proCreateImage",
      "prompt": "An epic fantasy battle scene with dragons, cinematic lighting, intricate details",
      "imageSize": "landscape_16_9"
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Pro costs more and is slower, but delivers stronger prompt adherence and finer detail. Use for hero shots where quality matters more than throughput.

Edit image (FAL)

FAL's edit operation accepts 1–3 reference images (vs sdcpp's 10):

json

{
  "steps": [{
    "$type": "imageGen",
    "input": {
      "engine": "fal",
      "model": "qwen2",
      "operation": "editImage",
      "prompt": "Make it daytime",
      "images": [
        "https://image.civitai.com/.../source.jpeg"
      ]
    }
  }]
}

Set your Civitai API token via the Token button in the navbar to enable Try It.

Request body — edit to customize (e.g. swap the image URL or prompt)

Valid JSON

Swap to proEditImage for the Pro tier variant.

Reading the result

Both engines emit the standard imageGen output — an images[] array, one entry per quantity:

json

{
  "status": "succeeded",
  "steps": [{
    "name": "0",
    "$type": "imageGen",
    "status": "succeeded",
    "output": {
      "images": [
        { "id": "blob_...", "url": "https://.../signed.jpeg" }
      ]
    }
  }]
}

Blob URLs are signed and expire — refetch the workflow or call GetBlob for a fresh URL.

Runtime

Path	Typical wall time per 1024×1024 image	`wait` recommendation
sdcpp Qwen-Image 20B	15–35 s	`wait=60` usually fine for `quantity: 1`
FAL Qwen2 (create / edit)	10–30 s depending on FAL queue	`wait=60` usually fine
FAL Qwen2 Pro (`proCreateImage` / `proEditImage`)	20–60 s depending on queue	`wait=60` sometimes; fall back to `wait=0` on busy periods

Large quantity or atypical aspect ratios push toward the 100-second request timeout — submit with wait=0 and poll.

Cost

Billed in Buzz on the workflow's transactions. Use whatif=true for an exact preview; see Payments (Buzz) for currency selection.

sdcpp Qwen-Image 20B — per-pixel + per-step scaling, with editImage carrying a flat higher base:

createImage / createVariant:
  total = 30 × (width × height / 1328²) × (steps / 20) × quantity

editImage:
  total = 40 × (width × height / 1024²) × (steps / 20) × (1 + (numImages − 1) × 0.1) × quantity

Shape	Buzz
`createImage`, 1024²/`steps: 20`/`quantity: 1`	~18
`createImage`, 1328²/`steps: 20`/`quantity: 1`	~30
`createImage`, 1024²/`steps: 20`/`quantity: 4`	~72
`editImage`, 1 ref, 1024²/`steps: 20`	40
`editImage`, 3 refs, 1024²/`steps: 20`	48

FAL Qwen2 (engine: "fal") — commercial tier routed through FAL. Base cost is fixed per operation, per image. createImage is cheapest; proCreateImage / proEditImage cost meaningfully more. Use whatif=true to confirm pricing for your shape — FAL pricing shifts independently of the sdcpp path.

Troubleshooting

Symptom	Likely cause	Fix
`400` with "ecosystem must be qwen"	Typo	Lowercase `"qwen"` — not `"Qwen"` or `"qwen2"` (that's the fal `model`, not the sdcpp ecosystem).
`400` with "version must be one of"	Picked a version that isn't valid for that operation	Edit supports `latest`/`2509`/`2511`; create + variant support `latest`/`2509`/`2512`.
`400` with unexpected "width/height" error on edit/variant	Dimensions conflict with source resolution	Omit `width`/`height`; they auto-populate from the source.
`400` with "imageSize must be one of" on fal	Arbitrary dimensions on FAL path	FAL Qwen2 uses the enum — pick `square_hd`, `landscape_16_9`, etc. Use the sdcpp path for arbitrary dimensions.
`400` with "images maxItems"	More than 10 source images on sdcpp `editImage`, or more than 3 on fal `editImage`	Trim the array.
LoRA has no effect on FAL	FAL Qwen2 doesn't support LoRAs	Switch to the sdcpp path.
Output ignores the prompt	`cfgScale` too low (Qwen wants ~2.5, far below SD1/SDXL's 7) or `enablePromptExpansion` rewriting your carefully-tuned text	Bump `cfgScale` toward 4 on sdcpp; set `enablePromptExpansion: false` on fal.
Request timed out (`wait` expired)	Large `quantity`, Pro tier on busy queue	Resubmit with `wait=0` and poll.
Step `failed`, `reason = "blocked"`	Prompt or input image hit content moderation	Don't retry the same input — see Errors & retries → Step-level failures.

SubmitWorkflow — operation used by every example here
GetWorkflow — for polling
Flux 2 / Flux 1 image generation — alternative open-weights families
SDXL / SD1 image generation — classic Stable Diffusion ecosystems
Image upscaling — chain after imageGen for higher-res output
Prompt enhancement — LLM-rewrite a prompt before feeding it in via $ref
Full parameter catalog: the Qwen20b<Operation>Input (sdcpp) and Qwen2<Operation>FalImageGenInput / Qwen2Pro<Operation>FalImageGenInput (fal) schemas in the API reference
imageGen endpoint OpenAPI spec — standalone OpenAPI 3.1 YAML covering the full imageGen surface; import into Postman / OpenAPI Generator

Qwen image generation ​

Prerequisites ​

sdcpp — Qwen-Image 20B (default path) ​

Text-to-image (createImage) ​

Picking a version ​

With LoRAs ​

Image-to-image (createVariant) ​

Edit image (editImage) ​

fal — FAL-hosted Qwen2 (with Pro tier) ​

FAL-specific parameters ​

Pro tier (proCreateImage / proEditImage) ​

Edit image (FAL) ​

Reading the result ​

Runtime ​

Cost ​

Troubleshooting ​

Related ​

Qwen image generation

Prerequisites

sdcpp — Qwen-Image 20B (default path)

Text-to-image (`createImage`)

Picking a `version`

With LoRAs

Image-to-image (`createVariant`)

Edit image (`editImage`)

fal — FAL-hosted Qwen2 (with Pro tier)

FAL-specific parameters

Pro tier (`proCreateImage` / `proEditImage`)

Edit image (FAL)

Reading the result

Runtime

Cost

Troubleshooting

Related