Image Generation with Gemini, OpenAI, xAI, and OpenRouter

Generate and edit images using Google Gemini, OpenAI GPT Image 2, xAI Grok Image, and OpenRouter APIs via shell scripts.

Available Providers

Model: gemini-3-pro-image (default, "Nano Banana Pro"). Alt: gemini-3.1-flash-image (Flash, 14 ratios), gemini-3.1-flash-lite-image (cheapest). The -preview IDs are past their shutdown date.
Strengths: Premium quality, up to 4K output, thinking mode, Google Search grounding, multi-turn editing with up to 14 reference images
Aspect ratios: 10 on Pro (1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3, 4:5, 5:4, 21:9); Flash adds 4 extreme ratios (1:4, 4:1, 1:8, 8:1)
Resolution: --image-size takes 1K, 2K, 4K on both Pro and Flash; Flash additionally supports 512 (UPPERCASE required)
Env var: GEMINI_API_KEY

Model: gpt-image-2 (default, snapshot gpt-image-2-2026-04-21); gpt-image-1.5 available as previous flagship via --model
Strengths: Superior text rendering, transparent backgrounds, up to 16 input images for editing, quality tiers
Sizes: on gpt-image-2, any WxH with both edges multiples of 16, longest edge up to 3840 and ratio at most 3:1 (such as 2048x1152, 3840x2160); older models take 1024x1024, 1536x1024 (landscape), 1024x1536 (portrait)
Quality: low (fast/cheap), medium, high (best fidelity)
Env var: OPENAI_API_KEY