Doubao API

ByteDance sells API access to its own Seed models, called Doubao in China, through two platforms: BytePlus ModelArk for international customers and Volcano Engine Ark for mainland China. ModelArk serves the Seed 2.0 Pro, Lite and Mini models and Seed 2.1 Turbo with up to 256K tokens of context, alongside ByteDance's Seedream image and Seedance video models and resold third-party models such as DeepSeek and GLM. Some newer models, such as Doubao Seed 2.1 Pro and Lite, are only on the mainland platform.

ModelArk's chat API is compatible with the OpenAI API: point the OpenAI SDK at https://ark.ap-southeast.bytepluses.com/api/v3 with a ModelArk API key. BytePlus also publishes its own SDKs for Python (arkruntime), Go and Java, and lists Responses and Messages APIs, batch inference, context caching and a Managed Agents API in the same reference.

Useful for a small team: each model comes with a free trial quota, and a "Free Tokens Only" mode suspends calls before you'd be billed; batch and "flex" online inference run at roughly half the standard price; and you can turn on application-layer encryption so requests are only decrypted inside ModelArk's inference sandbox.

Limits: prices step up for longer prompts, and context caching adds an hourly storage fee. ByteDance is headquartered in Beijing; for ModelArk, BytePlus says customer data is processed in Malaysia, Indonesia and/or the EU/EEA and isn't used for its own model training without your authorization, but inputs and outputs caught by the content filter are kept for 180 days in Malaysia.