why

people want to try codex models in Stagehand (also see benchmarks)

what changed

Codex needs a text verbosity and reasoning effort of medium (not low) so we set this using a conditional operator.

test plan

Ran evals

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Summary by cubic

Enable Codex models in Stagehand via the AI SDK with the right OpenAI provider options. Addresses STG-1324: Codex uses medium text verbosity and reasoning effort; non-Codex gpt-5 defaults stay the same.

• New Features
  • Detects Codex models (modelId includes "codex") and sets textVerbosity: "medium" and reasoningEffort: "medium".
  • Updates AISdkClient and AISdkClientWrapped to apply low/minimal reasoning defaults to gpt-5.1/5.2 only when not Codex.