openrouter-streaming-setup

# OpenRouter Streaming Setup ## Overview OpenRouter supports Server-Sent Events (SSE) streaming via `stream: true`, compatible with the OpenAI SDK. Streaming returns tokens as they're generated, reducing time-to-first-token (TTFT) from seconds to milliseconds. Usage stats are available via `stream_options: {include_usage: true}` in the final chunk. This skill covers Python and TypeScript streaming, SSE forwarding to browsers, and error recovery. ## Python: Basic Streaming ```python import os from openai import OpenAI client = OpenAI( base_url="https://openrouter.ai/api/v1", api_key=os.environ["OPENROUTER_API_KEY"], default_headers={"HTTP-Referer": "https://my-app.com", "X-Title": "my-app"}, ) # Stream with usage stats stream = client.chat.completions.create( model="anthropic/claude-3.5-sonnet", messages=[{"role": "user", "content": "Explain how HTTP streaming works"}], max_tokens=500, stream=True, stream_options={"include_usage": True}, # Get token counts in final chunk ) full_content = [] for chunk in stream: if chunk.choices and chunk.choices[0].delta.content: token = chunk.choices[0].delta.content print(token, end="", flush=True) full_content.append(token) # Final chunk contains usage stats if chunk.usage: print(f"\n---\nTokens: {chunk.usage.prompt_tokens} in + {chunk.usage.completion_tokens} out") result = "".join(full_content) ``` ## Python: Streaming with Metrics ```python import tim...