BytePlus Seedream

Invoke supports BytePlus’s Seedream image generation family through the BytePlus Ark API. Seedream is a strong fit for 2K/4K generations and multi-reference image composition.

Getting an API Key

1. Open the BytePlus Console and sign in.
2. Enable the Ark (model serving) product.
3. Create an API key with access to the Seedream models you plan to use.

Configuration

Add your key to api_keys.yaml in your Invoke root directory:

external_seedream_api_key: "your-seedream-api-key"

# Optional — change only if you need a different regional endpoint
external_seedream_base_url: "https://ark.ap-southeast.bytepluses.com"

Restart Invoke for the change to take effect.

Available Models

Model	Modes	Reference Images	Batch	Native Size
Seedream 5.0	txt2img, img2img	up to 14	up to 15	2K
Seedream 5.0 Lite	txt2img, img2img	up to 14	up to 15	2K
Seedream 4.5	txt2img, img2img	up to 14	up to 15	2K
Seedream 4.0	txt2img, img2img	up to 14	up to 15	2K

The 4.x / 5.x models are batch-capable and accept up to 14 reference images per request.

Model IDs

BytePlus uses date-stamped model IDs (e.g. seedream-5-0-260128). When BytePlus releases a new dated revision, the starter model IDs in Invoke need to be updated. Seedream 3.0 T2I (seedream-3-0-t2i-250415) was deprecated by BytePlus and replaced by Seedream 4.0.

Supported Aspect Ratios

All Seedream models share the same aspect ratio set: 1:1, 2:3, 3:2, 3:4, 4:3, 9:16, 16:9, 21:9, rendered at 2K.

Provider-Specific Options

Seedream exposes two provider-specific toggles in the parameters panel:

• Watermark — When enabled, BytePlus adds a small watermark to the output. Off by default.
• Optimize Prompt — When enabled, BytePlus rewrites your prompt server-side for better generation quality. Useful for short prompts; disable if you want the exact wording preserved.

Seed and guidance scale are not accepted by the 4.x / 5.x family.

Reference Images

4.x and 5.x Seedream models accept up to 14 reference images alongside the prompt. Invoke’s standard reference-image panel is used — drag images in, and they are forwarded as base64 PNGs to the API.

Tips

1. For multi-image composition (e.g. character + product), Seedream 4.5 is a good default.
2. When running large batches (num_images > 1 on 4.x / 5.x), Invoke uses the sequential_image_generation API flag — each image is returned as it completes.
3. Set external_seedream_base_url if you need to route through a region-specific Ark endpoint.