South Korea's Upstage Launches Solar Pro 4 for Complex AI Agent Tasks

South Korean AI lab Upstage launched Solar Pro 4, a commercial large model for complex AI agent tasks. It supports a 512K context window and 128K max output, letting users load multiple contracts, reports, and data files in one session. Pricing: $0.3 per million input tokens, $0.06 for cache reads, and $1.2 per million output tokens.

Solar Pro 4 excels in real-world benchmarks, scoring 57 on Terminal-Bench v2.1, 23 on τ³-Banking, and 71 on AA-LCR. Upstage demoed with a fictional coffee brand's store location analysis, completing policy filtering and generating an Excel workbook, review report, and slides in just three prompts. It's the first Korean lab model on Agent Arena, Code Arena: WebDev, and Text Arena, ranking 44th on Agent Arena.