Google Imagen vs Leonardo.Ai API

Google Imagen

Shutdown dates were published in the Gemini API changelog and the Vertex AI release notes, with replacements named. Discontinued. Calls to imagen model names fail on both the Gemini API and Vertex AI.

Leonardo.Ai API

Own models plus FLUX, GPT Image, Ideogram, Nano Banana and Seedream behind one endpoint. No per-image price list outside the logged-in calculator.

Google Imagen

1. Replace client.models.generate_images with client.models.generate_content and a gemini-3.1-flash-image model
2. Read images from the response content parts, not from generated_images
3. Don't budget from the Vertex Imagen price rows, they describe a retired product
4. If the job needs a mask-based inpaint, use another vendor's fill endpoint, since Gemini image editing is prompt-based

Leonardo.Ai API

1. Use POST /api/rest/v2/generations with a model name such as lucid-origin
2. Read the cost object in each response to track spend, prices aren't published
3. Send quality, not mode. mode was retired on 2026-05-04
4. Set a webhook callback URL on the key instead of polling long jobs
5. Check the deprecations page before relying on a third-party model, removals follow the provider