Solar Pro 4
Solar Pro 4 is Upstage’s hosted commercial flagship for long-running enterprise agents. It focuses on terminal tasks, multi-turn tool use, document-grounded reasoning, and producing deliverables across multiple files. It supports English, Korean, and Japanese, adjustable reasoning effort, a 512K context, and up to 128K output tokens. The model is offered through Upstage Console and partner APIs rather than open weights. Its August 11 launch blog precedes the August 20 press release. Benchmarks depend on agent environments and do not guarantee task completion in a particular production workflow.
2026-08-11
Undisclosed
Proprietary
Specifications
- Architecture
- Undisclosed
- License
- Proprietary
- Context Window
- 524,288 tokens
- Max Output
- 131,072 tokens
- Type
- text
- Modalities
- text
Benchmark Scores
Advanced Specifications
- Model Family
- Solar
- API Access
- Available
- Chat Interface
- Available
Capabilities & Limitations
- Capabilities
- reasoningtool usestructured outputlong context
- Known Limitations
- Public weights are not offeredTool execution and retrieval require external systemsGenerated results require validation
- Notable Use Cases
- enterprise agentsdocument synthesishigh-volume automation
- Function Calling Support
- Yes
- Tool Use Support
- Yes