Upstage gives Solar Pro 4 a 512K context

Upstage launched Solar Pro 4 with a 512K-token context window, up to 128K output tokens, and a 90% launch discount through September 10 on Upstage Console and OpenRouter. The company’s release reports 57 on Terminal-Bench v2.1, 23 on τ³-Banking, and 70.6 on SWE-Bench Verified, while pricing the API at $0.30 per million input tokens and $1.20 per million output tokens before the promotion. The model is positioned for long, multi-step work rather than open weights; builders extending Upstage’s two-H200 local-agent path can use the discount to test whether fewer retries and longer context actually lower completed-task cost, rather than treating vendor benchmarks as a production verdict.