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

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"},
)