DeepSeek has quietly released a preview of V4 to API customers, and the early reports from the developer community are causing significant excitement. The new model extends the context window to 256K tokens — double V3's 128K — while reportedly delivering substantial improvements on multi-step reasoning benchmarks. Notably, DeepSeek V4 appears to close the gap with frontier proprietary models on tasks requiring long-horizon planning, making it particularly attractive for autonomous agent workloads where context length is a hard constraint. Pricing remains in line with V3: roughly $0.14 per million input tokens and $0.28 per million output tokens, keeping it dramatically cheaper than GPT-4o or Claude Sonnet for high-volume agent pipelines.