이미지: X — 모델·오픈소스 영상 갈무리
Summary
- Nous Research has made Upstage's new agentic model Solar Pro 4 available for free on Nous Portal for one week
- The model is designed to break long documents into multiple steps and, when information is insufficient, ask for clarification instead of guessing
- During the same period, Nous Portal is also offering Hy3, Step 3.7 Flash, Laguna S, and Laguna XS for free
- 공개 채널
- Nous Portal (Nous Research 운영)
- 모델명
- Solar Pro 4
- 개발사
- Upstage(업스테이지)
- 발표일
- 2026년 8월 11일 (Nous Research, X)
- 무료 제공 기간
- 1주일
- 핵심 설계 목표
- 장문 문서 다단계 작업 처리, 정보 부족 시 추측 대신 재확인
- 동시 무료 모델
- Hy3, Step 3.7 Flash, Laguna S, Laguna XS
A new model opened up free for a week
AI model gateway Nous Portal has made a new model free for one week: Solar Pro 4, an agentic model built by Upstage. Nous Research announced this on X (formerly Twitter) on August 11, describing the model as designed to "complete multi-step tasks across long documents and recognize when information is insufficient, rather than making things up."
An agentic model goes beyond simply answering questions — it plans and executes multi-step tasks on its own. For example, the goal is for the model to independently handle a workflow like reading a contract dozens of pages long, summarizing it clause by clause, then identifying missing information and asking follow-up questions. The point Solar Pro 4 emphasizes is precisely this last part: not making things up when it doesn't know.
Why "not making things up" is hard
One of the chronic problems with large language models is hallucination — the tendency to produce plausible-sounding answers with no real basis. This is especially risky for agentic models that carry out tasks across multiple steps, since an incorrect assumption made at an early stage compounds as the process continues. Upstage's emphasis on Solar Pro 4's ability to recognize insufficient information and ask follow-up questions can be understood against this backdrop. That said, the announcement did not include benchmark figures to substantiate how reliable this capability actually is in practice.
Upstage and the Solar lineup
Upstage is a South Korean AI company known for its Solar series. In METAL LAB's ontology, the Solar family of models is registered as an Upstage development and handles the text modality. Solar Pro 4 is the latest entry in that lineup, though details such as parameter count or context length were not confirmed in this source.
Nous Portal's free lineup
Solar Pro 4 isn't the only model made free in this round. Nous Portal is also offering Hy3, Step 3.7 Flash, Laguna S, and Laguna XS for free during the same period. However, the free period varies by model, and Solar Pro 4's one-week window is among the shortest.
| Model | Developer (estimated) | Free access |
|---|---|---|
| Solar Pro 4 | Upstage | 1 week |
| Hy3 | Unconfirmed | Free |
| Step 3.7 Flash | Unconfirmed | Free |
| Laguna S / XS | Unconfirmed | Free |
Nous Portal extends 20% API discount for two more weeks
What this means
Nous Portal is a gateway service that bundles API access from multiple model providers into a single point of entry. This free opening gives users a chance to try out Solar Pro 4's multi-step task handling firsthand, without a separate contract. It's also worth noting that a South Korean developer's agentic model is being surfaced through an overseas gateway. The announcement did not specify pricing or terms for paid access once the free period ends, but combined with the ongoing 20% discount extension on the same platform, the environment for cheaply comparing multiple models is likely to continue for now.
