Pixwith Nano Banana 2 — AI Image Generation
Generate and edit images via the Pixwith API using the Nano Banana 2 model.
Supports text-to-image and image-to-image with up to 4 reference images,
multi-resolution output (1K / 2K / 4K), and flexible aspect ratios.
⚠️ CRITICAL — Do NOT Alter API Response Values
ALL values returned by the API (task_id, result_urls, image_url, upload_url, fields) are opaque tokens. Use them EXACTLY as returned — do NOT add, remove, or change even a single character. Store each value in a shell variable and reuse it directly. A single wrong character in task_id or result_urls will cause errors or broken links.
Setup
This skill requires a PIXWITH_API_KEY environment variable.
If the variable is not set, guide the user through these steps:
- Go to https://pixwith.ai/api and sign up / log in.
- Click "Add" to create a new API key and copy it.
- Add the key to
~/.openclaw/openclaw.json:
{
"skills": {
"entries": {
"nano-banana-image-gen": {
"enabled": true,
"env": { "PIXWITH_API_KEY": "key_your_key_here" }
}
}
}
}
Verify by running:
curl -s -X POST https://api.pixwith.ai/api/task/get_credits \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY"
A successful response looks like {"code":1,"data":{"credits":500}}.
Pricing
| Resolution | Credits per image |
|---|
| 1K | 10 |
| 2K | 15 |
| 4K | 20 |
Always inform the user of the cost before creating a task.
Model Parameters
- model_id:
0-41 (fixed)
- prompt (required): Describe the image to generate or the edit to apply.
- image_urls (optional): 1–4 publicly accessible image URLs for image-to-image mode.
- options.prompt_optimization (boolean, default
true): Auto-translate prompt to English.
- options.resolution (required):
1K, 2K, or 4K.
- options.aspect_ratio (required):
0 (auto-match input image), 1:1, 16:9, 9:16, 3:4, 4:3, 3:2, 2:3, 5:4, 4:5, 21:9.
Workflow A — Text-to-Image
Use when the user provides only a text prompt and no images.
Step 1: Check credits
curl -s -X POST https://api.pixwith.ai/api/task/get_credits \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY"
Verify data.credits is sufficient for the chosen resolution.
Step 2: Create task
curl -s -X POST https://api.pixwith.ai/api/task/create \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY" \
-d '{
"prompt": "<user_prompt>",
"model_id": "0-41",
"options": {
"prompt_optimization": true,
"resolution": "1K",
"aspect_ratio": "1:1"
}
}'
Response contains data.task_id and data.estimated_time (seconds).
Step 3: Poll for results
Wait for estimated_time seconds, then poll:
curl -s -X POST https://api.pixwith.ai/api/task/get \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY" \
-d '{"task_id": "<task_id>"}'
data.status == 1 → still processing, wait 5 seconds and poll again.data.status == 2 → done, data.result_urls contains the image URLs.data.status == 3 → failed, inform the user.
Present the EXACT result_urls to the user.
Workflow B — Image-to-Image
Use when the user provides one or more reference images plus a text prompt.
Step 1: Upload local images (if needed)
If the user provides a local file path (not a public URL), upload it first.
Upload constraints:
- Allowed formats:
.jpg, .jpeg, .png only
- Maximum file size: 10 MB
content_type must match the file: image/jpeg for .jpg/.jpeg, image/png for .png- The presigned upload URL expires in 10 minutes
1a. Get a presigned upload URL:
curl -s -X POST https://api.pixwith.ai/api/task/pre_url \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY" \
-d '{"image_name": "photo.jpg", "content_type": "image/jpeg"}'
Set content_type based on the file extension:
.jpg / .jpeg → "image/jpeg".png → "image/png"
Response:
data.upload_url — presigned POST data (url + fields)data.image_url — the final CDN URL to use in image_urls
1b. Upload the file using the presigned data:
curl -s -X POST "<upload_url.url>" \
-F "key=<upload_url.fields.key>" \
-F "Content-Type=<upload_url.fields.Content-Type>" \
-F "x-amz-credential=<upload_url.fields.x-amz-credential>" \
-F "x-amz-algorithm=<upload_url.fields.x-amz-algorithm>" \
-F "x-amz-date=<upload_url.fields.x-amz-date>" \
-F "x-amz-signature=<upload_url.fields.x-amz-signature>" \
-F "policy=<upload_url.fields.policy>" \
-F "file=@/path/to/local/image.jpg"
Fill every field from the upload_url.fields object into the form.
After upload, use data.image_url from step 1a as the image URL.
If the user already has a public image URL (starts with http), skip this step.
Step 2: Check credits
Same as Workflow A, Step 1.
Step 3: Create task with images
curl -s -X POST https://api.pixwith.ai/api/task/create \
-H "Content-Type: application/json" \
-H "Api-Key: $PIXWITH_API_KEY" \
-d '{
"prompt": "<edit_instruction>",
"image_urls": ["<image_url_1>", "<image_url_2>"],
"model_id": "0-41",
"options": {
"prompt_optimization": true,
"resolution": "1K",
"aspect_ratio": "0"
}
}'
When editing images, aspect_ratio: "0" auto-matches the input image dimensions.
Step 4: Poll for results
Same as Workflow A, Step 3.
Error Handling
All API responses follow {"code": 1, "message": "success", "data": {...}}.
When code is 0, message contains the error. Common errors:
Invalid API KEY — key is missing, wrong, or disabled.Credits not enough — user needs to purchase more credits at https://pixwith.ai/pricing.Invalid image format — only jpg, png, jpeg are supported.Invalid image url — the URL is not publicly accessible.
Defaults
When the user does not specify preferences, use these defaults:
- resolution:
1K
- aspect_ratio:
1:1 (text-to-image) or 0 (image-to-image)
- prompt_optimization:
true
