Doubao Seed 2 Pro API Guide 2026: ByteDance's Flagship LLM, Access & Costs

Published August 25, 2026 · 6 min read

ByteDance runs two product lines on the same Volcano Ark backbone: the Seedance video models and the Doubao Seed text family. With Seedance 2.5 making headlines, developers keep asking about the LLM side — here is the state of Doubao Seed 2 Pro and how to call it from outside China.

The Seed 2 family

ModelBest forContext
doubao-seed-2.0-proFlagship reasoning, long-form, tool use256K
doubao-seed-2.0-liteHigh-volume, cost-sensitive workloads256K
doubao-seed-2.0-codeCode generation & review256K

All three are served official-direct through NovAI with USD billing — the upstream platform itself requires a Chinese business account and CNY payment, which is the main barrier for international developers.

Calling it

from openai import OpenAI

client = OpenAI(api_key="sk-novai-...", base_url="https://aiapi-pro.com/v1")
r = client.chat.completions.create(
    model="doubao-seed-2.0-pro",
    messages=[{"role": "user",
               "content": "Summarize this contract and list risk clauses."}],
    max_tokens=4096,
)
print(r.choices[0].message.content)

Streaming, function calling and JSON mode all work through the same OpenAI-compatible surface. Live per-million pricing is on the marketplace page — it tracks the official rate card and is updated when ByteDance revises it.

Where Seed 2 Pro fits in 2026

The interesting property of the Doubao line is consistency: 256K context across Pro, Lite and Code means you can prototype on Pro, then drop the same prompts onto Lite for production volume without re-testing context behavior. For a cost-first alternative in the same ecosystem, ByteDance's own budget tier is worth benchmarking against DeepSeek and Qwen — see our cheapest-LLM roundup for the numbers.

Every new NovAI account starts with $2 free credit — enough to benchmark Seed 2 Pro against your current model on real prompts before committing.

Try it free on NovAI

$2 free credit · no card required · OpenAI-compatible API

Start Free →

Or test it in the playground →

Related: Seedance 2.5 video pricing · Cheapest LLM APIs this month