nanobot can generate and edit images through the `generate_image` tool. Enable the tool in WebUI Settings, then ask for an image normally in chat; the agent decides when to call it and can keep iterating on generated images in the same conversation.
The feature is disabled by default. Open **Settings → Image**, choose a configured provider and model, enable image generation, and save. The running gateway applies the change immediately. If that screen is not available in your installed version, use the manual config below.
This snippet uses the current built-in image-generation default so the JSON has concrete names. It is not a provider recommendation; replace `provider` and `model` with any supported image provider and model you intend to use.
4. Attach reference images when editing an existing image.
Generated images are rendered as assistant media in the chat. Follow-up prompts such as "make it warmer", "change the background", or "try a 16:9 version" can reuse the most recent generated artifact.
The WebUI hides provider storage details from the user. The agent sees the saved artifact path internally and can pass it back to `generate_image` as `reference_images` for iterative edits.
For providers that return image URLs, direct downloads use DNS pinning. When an explicit provider `proxy` is configured, nanobot rejects malformed URLs and locally identifiable private/internal targets on the initial URL and every redirect. Hostnames unavailable to local DNS are delegated to that trusted proxy, which owns final DNS resolution and network egress. Process-wide proxy environment variables are not used for these downloads.
The response must include generated images in `data[].b64_json` or `data[].url`. Native prediction APIs, such as Replicate's `/v1/models/{owner}/{model}/predictions`, are not directly compatible unless you put an OpenAI-compatible gateway in front of them.
The `apiBase` is required. The provider sends requests to `{apiBase}/images/generations` using the OpenAI Images API format with `response_format: "b64_json"`. The `apiKey` is optional for local or unauthenticated endpoints. Reference-image edits are not supported by the generic `custom` provider.
`extraBody` can adapt provider-specific quirks because it is merged last into the request body. Examples:
- Agnes AI documents URL responses, so use `"extraBody": {"response_format": "url"}`.
- Together AI documents `"response_format": "base64"`, so override the default.
- Volcengine Ark Seedream models may require size hints such as `"2K"`, `"3K"`, `"4K"`, or explicit dimensions. Set `tools.imageGeneration.defaultImageSize` or `providers.custom.extraBody.size` to a value supported by the selected model.
For compatibility with the default nanobot setting, custom maps `defaultImageSize: "1K"` to `1024x1024`. Other explicit size hints are passed through unchanged.
For reference-image edits, use a Gemini Flash image model:
```json
{
"providers":{
"gemini":{
"apiKey":"${GEMINI_API_KEY}"
}
},
"tools":{
"imageGeneration":{
"enabled":true,
"provider":"gemini",
"model":"gemini-2.5-flash-image"
}
}
}
```
Imagen 4 supports the aspect ratios `1:1`, `9:16`, `16:9`, `3:4`, and `4:3`. Unsupported ratios are ignored and the model uses its default. The `defaultImageSize` setting has no effect on Gemini models; sizing is controlled by `defaultAspectRatio` only. Reference images passed with an Imagen model are ignored (with a warning logged).
Ollama's experimental native image generation API works with local servers and hosted ollama.com models. Local access at `http://localhost:11434/api` does not require an API key; set `providers.ollama.apiKey` only when targeting `https://ollama.com/api`.
```json
{
"providers":{
"ollama":{
"apiBase":"http://localhost:11434/api"
}
},
"tools":{
"imageGeneration":{
"enabled":true,
"provider":"ollama",
"model":"x/z-image-turbo",
"defaultAspectRatio":"16:9",
"defaultImageSize":"2K"
}
}
}
```
Ollama maps `defaultAspectRatio` and `defaultImageSize` to native `width` and `height` values. Reference images are not supported by this integration.
StepFun (阶跃星辰) `step-image-edit-2` supports text-to-image generation. The `step-1x-medium` variant additionally supports **style-reference** image edits, where a reference image guides the visual style of the output.
Supported aspect ratios: `1:1`, `16:9`, `9:16`, `3:4`, `4:3`. Sizes are specified as `WIDTHxHEIGHT` (e.g. `1024x1024`, `1280x800`, `800x1280`).
```json
{
"providers":{
"stepfun":{
"apiKey":"${STEPFUN_API_KEY}"
}
},
"tools":{
"imageGeneration":{
"enabled":true,
"provider":"stepfun",
"model":"step-image-edit-2"
}
}
}
```
> [!NOTE]
> The StepFun provider reuses the existing `providers.stepfun` config block (the same one used for StepFun's LLM API). Set `providers.stepfun.apiKey` once and it is shared between text and image generation.
>
> When `step-image-edit-2` is used, `reference_images` are ignored (the model does not support style reference). Switch to `step-1x-medium` to use reference-image-guided generation.
`apiBase` takes precedence over the registry default, so with the StepPlan base URL configured, image requests are sent to `https://api.stepfun.ai/step_plan/v1/images/generations` — the same path prefix used for LLM calls. The API key is shared with the standard StepFun provider.
Zhipu (智谱) `glm-image` model supports text-to-image generation. The API returns temporary image URLs (valid for 30 days); nanobot downloads and re-encodes them as base64 data URLs.
Supported aspect ratios: `1:1`, `16:9`, `9:16`, `3:4`, `4:3`. Sizes can be specified as `WIDTHxHEIGHT` (e.g. `1280x1280`, `1728x960`) or using aspect ratio presets.
Supported aspect ratios: `1:1`, `16:9`, `9:16`, `3:4`, `4:3`. Sizes can be specified as `WIDTHxHEIGHT` (e.g. `1024x1024`, `1664x928`) or using aspect ratio presets.
For non-default config locations, the media directory is relative to the active config file's directory.
The JSON sidecar stores:
| Field | Meaning |
|-------|---------|
| `id` | Short generated image id, such as `img_ab12cd34ef56` |
| `path` | Local image path used internally for follow-up edits |
| `mime` | Detected image MIME type |
| `prompt` | Prompt used for the generation |
| `model` | Provider model |
| `provider` | Provider name |
| `source_images` | Reference image paths used for edits |
| `created_at` | Creation timestamp |
Do not paste base64 image payloads into chat. The agent should keep local artifact paths internal unless the user explicitly asks for debugging details.
## Prompting
Good image prompts include:
- Subject and scene.
- Composition, camera, or layout.
- Style, mood, lighting, and color palette.
- Exact text that must appear in the image, quoted.
- Constraints such as "keep the same character" or "preserve the logo".
Example:
```text
A minimal app icon for nanobot: friendly robot head, rounded square, soft blue and white palette, clean vector style, no text
```
For edits, describe what should change and what must stay fixed:
```text
Use the reference image. Keep the same robot and composition, change the palette to warm orange, and add a subtle sunrise background.
| Missing API key error | Configure `providers.<provider>.apiKey`; if using `${VAR_NAME}`, confirm the environment variable is visible to the gateway process |
| AIHubMix says `Incorrect model ID` | Use `model: "gpt-image-2-free"`; nanobot expands it to the required `openai/gpt-image-2-free` model path internally |
| Generation times out | Try a smaller/default image size, set AIHubMix `extraBody.quality` to `"low"`, or retry later |
| Reference image rejected | Reference image paths must be inside the workspace or nanobot media directory and must be valid image files |
