New image models: GPT Image 2.5, FLUX 3, Grok Imagine

Three image models arrive on Tchavi: GPT Image 2.5 Sunburst from OpenAI, FLUX 3 from Black Forest Labs and Grok Imagine Image 2 from xAI. The first is built for images with legible text, the second for photorealism and editing, the third for graphic styles at a single price.

In short

• Tchavi, an OpenAI-compatible AI API gateway you pay for with mobile money, adds gpt-image-2.5-sunburst, flux-3-image and grok-imagine-image-2.
• All three generate and edit images from references.
• Prices run from 16 credits (about KES 1.2) to 667 credits (about KES 50) per image, depending on the model, quality and size.
• One endpoint for all of them: POST /v1/images/generations.

GPT Image 2.5 Sunburst (OpenAI)

The precision tier of the GPT Image 2.5 range, released by OpenAI in September 2026. It renders legible text on the image, accents included: posters, flyers, menus.

• Three sizes: 1024×1024, 1024×1536 and 1536×1024, at the same price.
• Five qualities: low, medium, high, xhigh, max.
• Up to 16 reference images to edit or keep a style. Each reference adds 18 credits, because OpenAI bills input images.
• If you do not set quality, the request is billed at the max level. Always set the quality.

FLUX 3 (Black Forest Labs)

The image model of Black Forest Labs' FLUX 3 family. Skin, fabric and light look like photographs.

• Four sizes: 1K, 1.5K, 2K and 4K, each at its own price. Every aspect ratio from 21:9 to 9:21.
• Up to 10 reference images to edit or combine.
• One image per request. 4K costs more than twelve times 1K: keep it for print.

Grok Imagine Image 2 (xAI)

xAI's image model, released in August 2026. It handles strong graphic styles and short headlines well: posters, illustration, screen-print looks.

• Same price at 1K or 2K, at low or medium quality. If you set nothing, it produces at medium and 2K.
• Editing from a single reference image.
• One image per request.

Prices

Credits first, then KES at October 2026 rates (1 credit is about KES 0.076):

A concrete example: a menu poster at medium on GPT Image 2.5 costs 32 credits, about KES 2.4. With three reference images, add 54 credits (about KES 4).

One call to try it

curl -X POST https://tchavi.com/api/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TCHAVI_API_KEY" \
  -d '{
    "model": "gpt-image-2.5-sunburst",
    "prompt": "Poster for a kitenge fabric shop in Nairobi, title \"End of month sale\", screen-print style",
    "quality": "medium",
    "size": "1024x1536"
  }'

The response contains the image as base64 in data[0].b64_json, and the cost in the X-Credits-Used header. For FLUX 3, change model to flux-3-image and send resolution ("1K", "2K"…) instead of quality. For Grok, use grok-imagine-image-2.

How to try them

• Open the model pages: GPT Image 2.5 Sunburst, FLUX 3, Grok Imagine Image 2. Each shows a demo and the parameters in its API tab.
• Read the image generation documentation.
• Top up with mobile money from KES 250 (see countries and operators): your credits do not expire.

FAQ

Which one for a poster with text?

Start with GPT Image 2.5 Sunburst at medium. Then compare with Grok Imagine for short headlines: same prompt, and look at the result.

A host goes down: what happens?

For these three models, another host of the same model can take over. The advertised price does not change for you.

Can I choose the FLUX 3 size?

Yes, from four fixed sizes: 1K, 1.5K, 2K and 4K. Set it with resolution, otherwise the default size is billed.

create your account and top up KES 250

This article is part of the series "Building an AI product from Africa". Tchavi is an OpenAI-compatible AI API gateway: one key gives access to over 100 text, image, audio and video models, and you pay for it with mobile money, no bank card (countries and operators). More guides on the blog. Follow us: LinkedIn and X.