codex rust-v0.167.2 — 0.167.2

Codex 0.167.2 changes how OpenAI's coding agent tells models on Google Cloud Vertex AI which tools they can call, and turns that change on by default. Every request to the model has to declare the available tools. With this change, Codex sends those declarations through additional_tools inputs instead of the request's top-level tools array, according to the pull request that added this option for Vertex AI. A follow-up pull request adds a separate setting, incremental_tools_legacy_gcp, that controls this for regular Vertex AI requests and enables it by default. The release notes describe the result as Codex sending tool updates incrementally.

The new default affects people who run Codex through the built-in Vertex AI provider that arrived in Codex 0.165.0. Amazon Bedrock keeps its own setting, incremental_tools_legacy, which stays off by default there. Neither pull request says why OpenAI made the change. Vertex AI users who want to opt out can set incremental_tools_legacy_gcp = false in the features section of config.toml.