anhkieuthanh/opc/image-generation

Image Generation

Use the generate_image tool when the user asks you to create, render, draw, design, generate, or edit an image.

If the generate_image tool is not available in the current tool list, tell the user that image generation is not enabled for this nanobot instance.

When To Use

• Text-to-image: call generate_image with a concrete prompt.
• Image editing: pass the saved artifact path or user image path in reference_images.
• Iterative edits in the same conversation: prefer the most recent generated image artifact if the user says things like "make it brighter", "change the background", or "try another version".
• Ambiguous edits: ask a short clarifying question if multiple recent images could be the target.
• In the current chat, do not call message just to announce or resend generated images. The runtime attaches images from generate_image to the final assistant reply automatically.

Prompt Rules

Write prompts with enough detail for image models:

• Subject and scene.
• Composition and camera or layout.
• Style, mood, lighting, and color palette.
• Text that must appear in the image, quoted exactly.
• Constraints such as "keep the same character", "preserve the logo", or "do not change the background".

Artifact Rules

The tool stores generated images as persistent artifacts under nanobot's media directory and returns structured metadata:

• id: generated image id, such as img_ab12cd34ef56.
• path: local file path for internal follow-up edits.
• mime: image MIME type.
• prompt, model, and source_images: provenance for follow-up edits.

In normal user-facing replies, do not expose local filesystem paths. Keep the reply natural, for example "Done, I generated it." You may include the short image id when it helps the user refer to a specific image, but keep raw path internal unless the user explicitly asks for debug details or a local artifact reference. Never paste base64.

For follow-up edits, pass the prior artifact path to reference_images. If the user provides a new uploaded image, use that path as the reference instead.

Do not include internal replay markers such as [Message Time: ...], [image: /local/path], generate_image(...), or message(...) in user-facing replies.

Provider Notes

Do not ask users to paste API keys into chat. If configuration is needed, describe the fields; LLM provider and BYOK changes are hot-reloaded for new turns.

For OpenRouter, the image tool expects:

{
  "providers": {
    "openrouter": {
      "apiKey": "sk-or-..."
    }
  },
  "tools": {
    "imageGeneration": {
      "enabled": true,
      "provider": "openrouter",
      "model": "openai/gpt-5.4-image-2"
    }
  }
}

For AIHubMix, the image tool expects:

{
  "providers": {
    "aihubmix": {
      "apiKey": "sk-..."
    }
  },
  "tools": {
    "imageGeneration": {
      "enabled": true,
      "provider": "aihubmix",
      "model": "gpt-image-2-free"
    }
  }
}

AIHubMix gpt-image-2-free uses AIHubMix's unified predictions endpoint internally (/v1/models/openai/gpt-image-2-free/predictions), not the OpenAI Images /v1/images/generations endpoint. If it fails with "Incorrect model ID", do not assume the key lacks permission until the provider config, model name, and gateway restart have been checked.

providers.aihubmix.extraBody can be used for provider-specific options. For example, "extraBody": {"quality": "low"} is optional but can make gpt-image-2-free faster and less likely to time out.

Examples

Generate a new image:

generate_image(
  prompt="A minimal app icon for nanobot: friendly robot head, rounded square, soft blue and white palette, clean vector style, no text",
  aspect_ratio="1:1",
  image_size="1K"
)

Edit the latest generated artifact:

generate_image(
  prompt="Use the reference image. Keep the same robot and composition, but change the palette to warm orange and add a subtle sunrise background.",
  reference_images=["/home/user/.nanobot/media/generated/2026-05-08/img_ab12cd34ef56.png"],
  aspect_ratio="1:1",
  image_size="1K"
)