DeepSeek V4: The Complete Developer Guide (API, Pricing, Local Setup & Migration 2026)

Dev.to AI
Generative AI Open Source AI

DeepSeek V4 is the hottest LLM story of 2026. GPT-4-class performance at 1/10th the price. OpenAI-compatible API. Open weights for self-hosting. And a July 24 endpoint deprecation deadline that many developers are quietly missing. This is the guide I wish existed when I started migrating our agent stack to DeepSeek. Let's cover everything. What is DeepSeek V4? DeepSeek V4 (API model: deepseek-chat ) is the flagship model from DeepSeek AI.