Programming Tutorials

  Integrating Large Language Models (LLMs) into production pipelines is rarely as simple as pasting a curl command. When scaling with the Perplexity API, developers frequently hit two specific roadblocks: persistent   401 Unauthorized   errors despite valid keys, and   429 Too Many Requests   errors that disrupt service availability. These errors are rarely random. They are deterministic responses to protocol violations, header mismanagement, or rate-limiting strategies enforced by Perplexity's infrastructure (often fronted by Cloudflare). This guide dissects the root causes of these failures and provides production-grade implementation patterns in Python and Node.js to resolve them. The 401 Unauthorized Error: It’s Not Just Your Key When you receive a  401 Unauthorized , the immediate assumption is a typo in the API key. While possible, in a DevOps context, the issue is usually environment injection or header serialization. Root Cause Analysis Header Malfo...