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Gemini Image Series
Google Gemini’s native multimodal image series, three generations of Nano Banana plus dual-tier access:
  • Nano Banana 2 (Gemini 3.1 Flash Image Preview) — lightweight fast tier, low latency, low cost, exclusive support for Google text / image search augmentation, ideal for previewing, batches, and iteration
  • Nano Banana Pro (Gemini 3 Pro Image Preview) — flagship tier, native 4K output, professional fidelity, multi-step planning, built-in quality analysis
  • Nano Banana (Gemini 2.5 Flash Image Preview) — previous-generation workhorse, low latency, high cost-performance, multi-image fusion, character consistency
Each generation offers two tiers: standard tier (economical, value-oriented) and official direct tier (higher SLA, higher stability, higher price). The two tiers share the same model and capabilities; the difference lies in the channel and billing. We recommend selecting the corresponding -official model id directly to switch channels (clearer semantics), or you can set official_fallback: true on the standard tier to switch at runtime. Per-image billing. All versions support both Chinese and English prompts.

Pricing

Mode Quick Reference

Examples

After submitting, poll task status with GET /v1/tasks/{task_id}. See Task System for details.

Available Models

Common Parameters

string
required
Pick one from the Available Models list
string
default:"generate"
Operation type, allowed values:
  • generate — text-to-image (default)
  • image2image — image-to-image (requires image_urls)
  • edit — image editing (instruction-based / inpainting)
  • reference — multi-image reference fusion
  • search_grounded — search augmentation (3.1 Flash series only)
string
required
Image description text; supports CN/EN. The Gemini series excels at natural-language instructions and handles multi-step, multi-constraint prompts well.
integer
default:"1"
Number of images to generate (multiple per call)
integer
default:"-1"
Random seed; -1 means random. A fixed value reproduces similar results.
string
default:"1:1"
Aspect ratio. Allowed values depend on the model:Standard 10 (supported by all models):
  • 1:1 — square
  • 2:3 / 3:2 — portrait/landscape camera
  • 3:4 / 4:3 — portrait/landscape standard
  • 4:5 / 5:4 — portrait/landscape social
  • 9:16 / 16:9 — portrait/landscape widescreen
  • 21:9 — ultra-wide
Extreme ratios (3.1 Flash series only):
  • 1:4 / 4:1 — tall column / banner
  • 1:8 / 8:1 — extreme column / extreme banner
string
default:"1K"
Output resolution, depends on model:
  • 3 Pro: 1K / 2K / 4K
  • 3.1 Flash: 0.5K / 1K / 2K / 4K
  • 2.5 Flash: 1K
string[]
Reference image URL array. image2image / edit typically takes one image; reference takes multiple.
string
Webhook callback URL, invoked when the task reaches a terminal state. See Callback Mechanism.
string[]
Callback event filter, e.g. ["completed", "failed"]

Model-Specific Parameters

model id: gemini-3-pro-image-preview-officialSeries: Nano Banana Pro · Official DirectSupported actions: generate / image2image / edit / referenceresolution: 1K / 2K / 4Kaspect_ratio: standard 10Highlights: Identical model to the 3 Pro standard tier, with a better channel and stability — suited for SLA-sensitive production lines. Priced ~2.7× the standard tier.
boolean
default:"false"
This model is already on the official direct tier, so this is typically unnecessary. The field is kept for upstream parameter-template compatibility.

Resource Limits