DeepSeek has reopened access to its core programming interface after nearly three weeks, resuming a service crucial for broader adoption of its AI model. The Chinese startup drew attention in January with a platform rivaling OpenAI’s and has allowed customers to top up credits again after suspending them in early February. DeepSeek’s move coincided with Alibaba's launch of a preview for its latest AI model and ByteDance’s testing of a deep reasoning model.  DeepSeek claims to have developed a ChatGPT rival at lower costs and has seen strong demand despite scrutiny from foreign governments.