GPT-5.6 Sol's 1M context in Codex now works with ChatGPT accounts.
Leave it off for small tasks. Default is already tuned for speed and cost.
~/.codex/config.toml
model = "gpt-5.6-sol"
model_context_window = 1000000
model_auto_compact_token_limit = 900000
GPT-5.6 Sol 1M in Codex. This used to only work for API keys, but we just flipped the switch and works for usage through ChatGPT accounts now too.
The same warning applies, there is a reason the current context length is the default, we have tuned it to ~perfection. But you do you!