openrouter-upgrade-migration

# OpenRouter Upgrade & Migration ## Current State !`npm list openai 2>/dev/null | head -5` !`pip show openai 2>/dev/null | head -5` ## Overview Migrating to OpenRouter from a direct provider API (OpenAI, Anthropic) is minimal: change `base_url` and `api_key`, add two headers. The OpenAI SDK works natively with OpenRouter. This skill covers migrating from direct APIs, switching between models, upgrading SDK versions, and running comparison tests. ## Migration from Direct OpenAI ```python # BEFORE: Direct OpenAI from openai import OpenAI client = OpenAI(api_key=os.environ["OPENAI_API_KEY"]) response = client.chat.completions.create( model="gpt-4o", messages=[{"role": "user", "content": "Hello"}], max_tokens=200, ) # AFTER: Via OpenRouter (3 lines changed) from openai import OpenAI client = OpenAI( base_url="https://openrouter.ai/api/v1", # ← Changed api_key=os.environ["OPENROUTER_API_KEY"], # ← Changed default_headers={ # ← Added "HTTP-Referer": "https://my-app.com", "X-Title": "my-app", }, ) response = client.chat.completions.create( model="openai/gpt-4o", # ← Add provider prefix messages=[{"role": "user", "content": "Hello"}], max_tokens=200, ) ``` ## Migration from Direct Anthropic ```python # BEFORE: Direct Anthropic SDK import anthropic client = anthropic.Anthropic(api_key=os.environ["ANTHROPIC_API_KEY"]) response = client.messages.create( model="claude-3-5-sonnet-2024...