Multimodal

Gateway accepts multimodal content natively. Include image or document content blocks in your messages and Gateway routes to a capable model. No configuration needed. Gateway automatically detects which models support each modality and translates content to the provider’s format.

Supported content types

Quick example

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from merge_gateway import MergeGateway
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client = MergeGateway(api_key="YOUR_API_KEY")
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response = client.responses.create(
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    model="openai/gpt-5.1",
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    input=[
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        {
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            "type": "message",
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            "role": "user",
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            "content": [
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                {"type": "text", "text": "What's in this image?"},
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                {"type": "image_url", "url": "https://example.com/photo.jpg"},
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            ],
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        }
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    ],
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)
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print(response.output[0].content[0].text)

Model compatibility

Gateway auto-detects multimodal capabilities from vendor-specific model metadata, so support tracks the live catalog rather than a fixed list. Use GET /v1/models and inspect vendors.<vendor>.capabilities.input to see whether the route you plan to use supports image or document inputs, or filter by input type in the model catalog.

Next steps