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Doubao Seed 2.1 Pro

字节跳动Chatin 0.9 · out 4.5 Credits / 1M tokens≈$0.9 / $4.5Available
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Doubao-Seed-2.1-pro is ByteDance's flagship general model in the Seed 2.1 family, with upgraded multimodal understanding, deep thinking, and agentic tool use. Access it through Velokey's unified endpoint with below-list pricing.

Multimodal understandingDeep-thinking reasoningAgentic tool useLong context

Use cases

Agentic & tool-augmented workflows · Multimodal document & chart analysis

Input

Text, image

Output

Text

Billing

Per token

Model Type:
0.7
02
2048
2568192
doubao-seed-2-1-pro

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Sign up to get $0.5 in free credits — about 20 free images

Pricing details

Transparent usage-based pricing with no hidden fees.

Detailed Pricing

Usage-based pricing breakdown

SpecPrice
Input/1M tokens0.9 Credits≈$0.9
Output/1M tokens4.5 Credits≈$4.5
Cache Read/1M tokens0.18 Credits≈$0.18

Billing Rules

  • Output price varies by model, resolution, quality, duration, or token usage.
  • Uploaded reference files may be charged separately when supported.
  • Add-on capabilities such as web search or image search may be billed per request.
  • Token-based models are billed by input and output tokens.
  • If the primary route is unavailable, Velokey may automatically switch to a stable fallback route when possible.
  • Usage is pay-as-you-go with transparent credit deduction.

* Final cost depends on the generated result.

Related models

Explore other models in the same family.

Affordable Doubao-Seed-2.1-pro API

Access ByteDance's Doubao-Seed-2.1-pro on Velokey — the all-round flagship of the Seed 2.1 family with upgraded multimodal understanding, deep thinking, agentic tool use, and long context, plus a unified endpoint and below-list pricing for production apps.

Meet Doubao-Seed-2.1-pro and its API access

Doubao-Seed-2.1-pro is the all-round flagship general model in ByteDance's Doubao Seed 2.1 family, a full upgrade over Seed 2.0 with improved quality across the board. It unifies multimodal understanding across text, image, video, document, and audio, adds a controllable deep-thinking reasoning mode, and excels at complex instructions, multi-constraint tasks, and multi-step planning. It strengthens agentic tool use and function calling, supports streaming and structured outputs, and keeps a long context window. Velokey provides an affordable, easy-to-integrate Doubao-Seed-2.1-pro API: a unified chat endpoint, a clear request flow, and below-list pricing for production systems, agent pipelines, and automation tools.

Multimodal understanding

Unifies text, image, video, document, and audio input; upgraded visual and cross-modal perception parses complex-layout documents, charts, and diagrams, producing structured results at high fidelity.

View Documentation →
Multimodal understanding

Deep-thinking reasoning

A controllable deep-thinking reasoning mode you can turn on or off, excelling at complex instructions, multi-constraint tasks, and multi-step planning, and steadier than Seed 2.0 on long-chain reasoning.

View Documentation →
Deep-thinking reasoning

Agentic tool use

Strengthened agentic tool use and function calling auto-orchestrate retrieval, tools, and multi-step tasks, with streaming and structured outputs, reliably driving end-to-end agent flows.

View Documentation →
Agentic tool use

Long context

A long context window holds long documents, long conversations, and multi-step tasks, keeping stable context memory while decomposing and executing long-chain work.

View Documentation →
Long context

How to deploy the Doubao-Seed-2.1-pro API on Velokey

Get started with just a few steps.

1

Sign up and get an API Key

Sign in to the Velokey console to generate an API Key that authenticates every request sent to Doubao-Seed-2.1-pro.

2

Configure request parameters

Set model to doubao-seed-2-1-pro and submit messages. Control deep thinking via reasoning_effort (minimal/low/medium/high), and use the long context for multimodal and complex long-chain tasks.

3

Integrate and start calling

Send requests to Velokey's unified /v3/chat/completions or /v3/responses endpoint to power agents and automation, with usage managed in one console.

Real-world use cases for Doubao-Seed-2.1-pro

From agentic tool use to multimodal analysis, covering many high-autonomy scenarios.

Agentic & tool-augmented workflows

Strengthened tool use and function calling auto-orchestrate retrieval, tools, and multi-step tasks — fit for building agents that plan, call tools, and deliver end to end.

Deep reasoning & complex solving

The controllable deep-thinking mode fits complex instructions, multi-constraint tasks, and multi-step planning, decomposing and solving long-chain problems reliably.

Multimodal document & chart analysis

Unifies understanding of text, image, document, and chart; upgraded visual perception parses complex layouts — fit for complex analysis and structured extraction.

Image, video & audio understanding

Unified understanding of image, video, and audio input — fit for multimodal content analysis and cross-modal QA.

High-frequency ToB tasks

Strong on high-frequency ToB tasks such as information extraction, grounded QA, and text analysis — fit for enterprise batch processing.

Structured & streaming output

Supports structured and streaming output with Function Call, web search, knowledge base, and MCP — fit for tool-augmented workflows.

Why choose Velokey for Doubao-Seed-2.1-pro

Discount on list price

Call Doubao-Seed-2.1-pro at a lower price on Velokey — pay-as-you-go with no forced subscription, reducing upfront cost.

Unified API interface

One API Key accesses Doubao-Seed-2.1-pro and other models — no juggling multiple accounts and keys, simplifying integration.

Automatic implicit caching

Implicit caching needs no configuration — common request prefixes are cached automatically and billed at the cache-hit rate, lowering cost on repeated prefixes.

Stable and highly available

Automatic failover and stable fallback routes maintain availability when the primary route is down, keeping production reliable.

API Reference

Complete API call examples and parameter descriptions

Endpoint

https://api.velokey.ai/v1/chat/completions

Authentication

Bearer YOUR_API_KEY

Request Example

curl https://api.velokey.ai/v1/chat/completions \
  -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "doubao-seed-2-1-pro",
    "messages": [{"role": "user", "content": "Hello!"}],
    "temperature": 0.7
  }'

Response Example

{
  "id": "req_abc123",
  "model": "doubao-seed-2-1-pro",
  "created": 1234567890,
  "data": { ... }
}

Doubao-Seed-2.1-pro API FAQ

What is Doubao-Seed-2.1-pro?

It is the all-round flagship general model in ByteDance's Doubao Seed 2.1 family, a full upgrade over Seed 2.0. It unifies multimodal understanding across text, image, video, document, and audio, adds a controllable deep-thinking reasoning mode, and strengthens agentic tool use and function calling, with streaming and structured outputs. The request model id is doubao-seed-2-1-pro (full version doubao-seed-2-1-pro-260615).

How large is the context and which modalities are supported?

It has a 256K-token context window with a max input of 224K, max output of 128K, and max thinking of 128K tokens. It accepts text, image, video, document, and audio input and returns text; vision quality has three tiers — low / high / xhigh — defaulting to high, with xhigh for dense text, complex charts, and rich detail.

How do deep thinking and implicit caching work?

Thinking depth is controlled via reasoning_effort (minimal/low/medium/high), where minimal means no thinking; the system fixes temperature=1 and top_p=0.95. Implicit caching is automatic with no configuration — common request prefixes (typically needing at least 1024 tokens) are cached, and hits are billed at the cache-hit rate.

What tools and APIs are available?

It supports Function Call, web search, knowledge base, and MCP, plus more agentic tool use and orchestration. APIs include Chat Completions (/v3/chat/completions), Responses (/v3/responses), and Tokenization, with streaming and structured outputs. It is strong on high-frequency ToB tasks such as information extraction, grounded QA, and text analysis.

How is it billed on Velokey?

Official pricing is ¥0.8 input / ¥4 output per million tokens (input at the up-to-32K tier), with cache hits at ¥0.16 per million tokens. This page's pricing area shows the current Velokey price, billed by input and output tokens with a discount on list price.

Start building with Doubao Seed 2.1 Pro today

Use one API key to access low-cost, stable AI models through Velokey.

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