Claude Sonnet 4.5 Thinking
Balanced Claude model for coding, analysis, agent workflows, and cost control
Model facts
- Context window
- 1M tokens
- Maximum output
- 64K tokens
- Cheapest paid input
- $3 per 1M tokens
- Cheapest paid output
- $15 per 1M tokens
- Open weights
- no
- Providers
- 1
Capabilities and modalities
reasoning, tool calling, structured output, attachments, temperature control, text, image, pdf.
Observed price history
- 2026-08-24: $3 input / $15 output per 1M tokens
API providers
- NanoGPT — model id claude-sonnet-4-5-20250929-thinking; $3 input / $15 output per 1M tokens; provider documentation