GPT-5.6 Sol ships with five reasoning levels from "Light" to "xhigh," plus "Max" and "Ultra" modes that deploy multiple sub-agents in parallel. OpenAI's Vaibhav Srivastav recommends starting low and only scaling up when needed.

OpenAI released GPT-5.6 as Sol, Terra, and Luna, adding Programmatic Tool Calling, ultra multi-agent mode, and tier pricing.

GPT-5.6 Sol ships with five reasoning levels from "Light" to "xhigh," plus "Max" and "Ultra" modes that deploy multiple sub-agents in parallel. OpenAI's Vaibhav Srivastav…