OpenAI engineer Nikunj Handa says GPT-6 Astra ships three Responses API upgrades: async function calling (the model can keep going while tools run), mid-turn steering (inject messages or tool outputs during reasoning), and changing reasoning effort without breaking cache. Details are in OpenAI’s latest-model developer guide.

Key Takeaways

  • ✓Async function calling: model continues while tools run, cutting idle multi-tool loops.
  • ✓Mid-turn steering: inject messages or tool outputs during reasoning without a full restart.
  • ✓Change reasoning effort without breaking cache—useful for cost/latency tuning.
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