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OpenAI

GPT-5.6 Terra Pro

GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Model facts

Context window
1.05M tokens
Maximum output
128K tokens
Cheapest paid input
$1 per 1M tokens
Cheapest paid output
$6 per 1M tokens
Open weights
no
Providers
4

Capabilities and modalities

reasoning, tool calling, structured output, attachments, text, image, pdf.

Observed price history

  • 2026-08-24: $1 input / $6 output per 1M tokens
  • 2026-08-28: $2 input / $12 output per 1M tokens
  • 2026-08-31: $1 input / $6 output per 1M tokens

API providers

  • OpenRouter (batch) — model id openai/gpt-5.6-terra-pro:batch; $1 input / $6 output per 1M tokens; provider documentation
  • NanoGPT — model id openai/gpt-5.6-terra-pro; $2 input / $12 output per 1M tokens; provider documentation
  • OpenRouter — model id openai/gpt-5.6-terra-pro; $2 input / $12 output per 1M tokens; provider documentation
  • Venice AI — model id openai-gpt-56-terra-pro; $3.12 input / $18.75 output per 1M tokens; provider documentation