Estimated spend for typical coding and autonomous agent workloads based on published per-token rates:
Grok 4.20 Reasoning · 10M In + 2M Out—Claude Sonnet 5.5 · 10M In + 2M Out$4.00Billing ModelPrepaid · $0 Hard Stop
When to Route to Grok 4.20 Reasoning vs Claude Sonnet 5.5
Because Newton’s exposes both grok-4.20-reasoning and claude-sonnet-5-5 behind the same API key and base URL, engineering teams frequently combine both models in the same workflow: