V4.1-Flash Migration Guide: Routing, Vision Input and Off-Peak Windows
What Changed
Since September 14, 2026, v4-pro API calls auto-route to V4.1-Flash. Use deepseek-flash explicitly.
Checklist
- 1M-token context for long documents
- Pass images directly in messages — no separate vision endpoint
- Off-peak window (UTC 16:30–00:30) halves prices
- Stable system prompts maximize $0.003 cache hits