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Implementing Server-Sent Events (SSE) for Perplexity API Streaming in Python

  You trigger a standard REST request to the Perplexity API, expecting a quick JSON response. Instead, your Python script hangs. Five seconds pass. Ten seconds. Finally, either a massive payload dumps all at once, or your load balancer severs the connection due to a timeout. This behavior isn't a bug in the API; it is a mismatch in consumption patterns. Perplexity, like most modern LLM providers, relies on Server-Sent Events (SSE) to deliver tokens as they are generated. If you treat this connection like a standard synchronous HTTP request, you are blocking I/O until the entire generation is complete. This article details the root cause of this latency and provides a production-grade Python implementation to handle Perplexity's streaming data correctly. The Root Cause: HTTP Buffering vs. Event Streams To understand why standard requests fail (or appear to lag), we must look at the underlying transport mechanism. The Blocking Model In a typical HTTP interactions (e.g.,  request...