Gemini image generation accepts Imagen parameters silently, ignores them, returns 200 OK with wrong output — half-migrated code ships undetected.
Summary
Silent failures in API migrations cascade downstream weeks later with no error signal. Response shape, endpoint, and parameter names all differ between Imagen and Gemini; defensive parsing masks the breakage until production assets stop appearing.
Why it matters
Silent failures in API migrations cascade downstream weeks later with no error signal. Response shape, endpoint, and parameter names all differ between Imagen and Gemini; defensive parsing masks the breakage until production assets stop appearing.
Implementation verdict
Replaces Imagen 4.0 models entirely. Requires full rewrite: new endpoint (:generateContent vs :predict), new response path (candidates[0].content.parts[0].inlineData vs predictions[0].bytesBase64Encoded), removed batch parameter (sampleCount), moved aspect-ratio namespace, dropped safety controls (personGeneration). Not ready to swap model strings. Mask-based editing has no replacement — audit that surface before committing to migration.
Sources
Dev Signal
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