Seed 1.6 Flash
by ByteDance SeedReleased Dec 23, 2025
bytedance-seed/seed-1.6-flash- Reads images
- Calls tools
- Answers in a JSON schema
- Reasons before it answers
Seed 1.6 Flash is an ultra-fast multimodal deep thinking model by ByteDance Seed, supporting both text and visual understanding. It features a 256k context window and can generate outputs of...
- Input / 1M tokens
- $0.09
- Output / 1M tokens
- $0.36
- Context
- 262K
- Longest answer
- 33K
What it costs
What each call is charged to the token's AI credit.
| Billed for | You pay |
|---|---|
| Input tokens | $0.09 / 1M |
| Output tokens | $0.36 / 1M |
| Prompts over 128,000 tokens | $0.12 in, $0.96 out |
A typical call
A short chat turn: 2,000 tokens in, 500 out.
- per call
- $0.0004
- calls per $20
- 56K
What it can do
From its listing. The router passes every field through.
- Reads imagesYes
- Reads files and PDFsNo
- Hears audioNo
- Calls toolsYes
- Answers in a JSON schemaYes
- Reasons before it answersYes
- Searches the webNo
- Caches long promptsNo
- Draws imagesNo
Call it
Any router key works, in the format your SDK already speaks.
import OpenAI from "openai";const ai = new OpenAI({ baseURL: "https://relayfor.si/api/v1", apiKey: process.env.RELAYFOR_ROUTER_KEY,});const reply = await ai.chat.completions.create({ model: "bytedance-seed/seed-1.6-flash", messages: [{ role: "user", content: "Welcome the 1,000th holder in one line." }],});Specifications
What its maker and providers list for it.
- Reads
- Images, Text, and Video
- Writes
- Text
- Context
- 262,144 tokens
- Longest answer
- 32,768 tokens
- Released
- Dec 23, 2025
- Retires
- Nov 11, 2026
- Moderation
- None
Request fields
The fields its providers accept, passed through as you send them.
- frequency_penalty
- include_reasoning
- max_tokens
- reasoning
- response_format
- stop
- structured_outputs
- temperature
- tool_choice
- tools
- top_p
Questions
How much does Seed 1.6 Flash cost?
$0.09 per million input tokens and $0.36 per million output tokens, paid from the token's AI credit. A call of 2,000 tokens in and 500 out costs about $0.0004.
How do I call Seed 1.6 Flash?
Make a router key for one of your tokens on the dashboard, point any OpenAI or Anthropic SDK at https://relayfor.si/api/v1 and send the model id bytedance-seed/seed-1.6-flash. The token's AI credit pays for each call.
How long a prompt can Seed 1.6 Flash take?
Up to 262,144 tokens of context, and up to 32,768 tokens in one answer.
Are my prompts stored?
No. The RFS Router passes each call through and keeps only its token counts and cost, for the token's usage page.
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