Solar Pro 4
by UpstageReleased Aug 10, 2026
upstage/solar-pro4- Calls tools
- Answers in a JSON schema
- Reasons before it answers
- Caches long prompts
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in office productivity, document-intensive...
- Input / 1M tokens
- $0.11
- Output / 1M tokens
- $0.43
- Context
- 524K
- Longest answer
- 131K
What it costs
What each call is charged to the token's AI credit.
| Billed for | You pay |
|---|---|
| Input tokens | $0.11 / 1M |
| Output tokens | $0.43 / 1M |
| Cached input, read | $0.022 / 1M |
A typical call
A short chat turn: 2,000 tokens in, 500 out.
- per call
- $0.0004
- calls per $20
- 46K
What it can do
From its listing. The router passes every field through.
- Reads imagesNo
- Reads files and PDFsNo
- Hears audioNo
- Calls toolsYes
- Answers in a JSON schemaYes
- Reasons before it answersYes
- Searches the webNo
- Caches long promptsYes
- 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: "upstage/solar-pro4", messages: [{ role: "user", content: "Welcome the 1,000th holder in one line." }],});Specifications
What its maker and providers list for it.
- Reads
- Text
- Writes
- Text
- Context
- 524,288 tokens
- Longest answer
- 131,072 tokens
- Reasoning effort
- none to max
- Intelligence index
- 28.2 (#53 of 220 rated)
- Released
- Aug 10, 2026
- Moderation
- None
Request fields
The fields its providers accept, passed through as you send them.
- frequency_penalty
- include_reasoning
- max_tokens
- parallel_tool_calls
- presence_penalty
- reasoning
- reasoning_effort
- response_format
- structured_outputs
- temperature
- tool_choice
- tools
- top_p
Questions
How much does Solar Pro 4 cost?
$0.11 per million input tokens and $0.43 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 Solar Pro 4?
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 upstage/solar-pro4. The token's AI credit pays for each call.
How long a prompt can Solar Pro 4 take?
Up to 524,288 tokens of context, and up to 131,072 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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