Solar Mini 4

Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524K context window. It is built for agentic use cases where response speed and cost matter, with fluent Korean alongside strong English and Japanese, and support for long-context workloads. When using BYOK with ZDR enforcement, the Console API key must belong to a ZDR-enabled Upstage organization. Contact Upstage to enable ZDR on your org.

ChatUpstage524k tokens$0.0545 / $0.218 · 1M

upstage/solar-mini4

Context
524k tokens
Completion cap
131,072
Tools
Yes
JSON
Yes
Released
2026-09-23

Call it from Geek Hub

Same OpenAI SDK. Change the base URL and the model id.

curl https://api.geekhub.mx/v1/chat/completions \
  -H "Authorization: Bearer $GEEKHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "upstage/solar-mini4",
    "messages": [{"role": "user", "content": "Hola"}]
  }'
Get an API key

Frequently asked questions

What is Solar Mini 4?
Solar Mini 4 is Upstage's compact, cost-efficient language model, a 35B-parameter mixture-of-experts with 3B active parameters and a 524K context window. It is built for agentic use cases where response speed and cost matter, with fluent Korean alongside strong English and Japanese, and support for long-context workloads. When using BYOK with ZDR enforcement, the Console API key must belong to a ZDR-enabled Upstage organization. Contact Upstage to enable ZDR on your org. Solar Mini 4 runs on the Geek Hub API (OpenAI-compatible). Model id: upstage/solar-mini4.
Is Solar Mini 4 free?
No. Input is $0.0545 per 1M tokens and output is $0.218 per 1M tokens on Geek Hub (markup included).
What is the context length of Solar Mini 4?
Solar Mini 4 has a 524k tokens context window. It supports up to 131,072 completion tokens.
Does Solar Mini 4 support tool calling and structured outputs?
Solar Mini 4 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
When was Solar Mini 4 released?
Solar Mini 4 was released on 2026-09-23.

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