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BananaHub speaks the Google Gemini generateContent wire format. You can keep using Google’s official google-genai SDK — or any Gemini-compatible client — and just point it at BananaHub.

Base URL

Pass this as the SDK’s base_url:
The SDK appends /v1beta/models/... itself, so keep the /api/gemini suffix.

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How it differs from the native API

The Gemini-compatible endpoint is synchronous: a single request returns the image inline, in Gemini JSON. There are no jobs to poll and no webhooks.
Both APIs use the same BananaHub API key and the same balance. Pick whichever fits your stack.

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Authentication

Send your BananaHub API key as x-goog-api-key. When you set api_key on the SDK client, it adds this header for you. A ?key= query parameter is also accepted. The key must be scoped for the model you request — see Authentication. A key without permission for the model returns 403 PERMISSION_DENIED.

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Models

Use any of the supported Gemini model IDs: Set the aspect ratio and size through imageConfig (aspectRatio, imageSize). imageSize is passed through to and validated by the model: supported values are 1K (default), 2K, 4K, plus 512px on NanoBanana 2. An unsupported value returns 400 INVALID_ARGUMENT. See Aspect ratios.
Billing is per the requested size, with 1K as the floor: 512px is billed at the 1K rate. 2K and 4K are billed at their own rates.

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Supported methods

Both directions are a full passthrough: any generationConfig, safetySettings, systemInstruction, or tools fields you send reach the model unchanged, and the complete Gemini response — including usageMetadata, finishReason, and safetyRatings — is returned verbatim. The only request-shaping is the imageSize validation described above (and NanoBanana being fixed at 1K).

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Billing

You’re billed per generated image, at the same price as the native API. A prompt blocked for safety returns 200 with finishReason: IMAGE_SAFETY and no image, and is not charged.

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Limits

The request body — prompt plus any base64 input images under inlineData — must not exceed 200 MB. A larger request returns 400 INVALID_ARGUMENT.

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Next steps

SDK quickstart

Generate, edit, and stream images with the google-genai SDK.

Errors

The Gemini error envelope and status codes.