Codex 0.155.0-alpha.6 makes the Guardian reviewer prompt configurable and moves its lifecycle into an extension

GitHub·medium signalXBlueskyLinkedInCopy link

The 60 commits between rust-v0.155.0-alpha.4 and alpha.6 (published 2026-09-15 02:00 UTC, with an empty release body as every Codex alpha has) include "Allow configuring the Guardian prompt template" (#45516), Guardian reviewers routed through ThreadManager for inline parents (#45518), reviewer startup and lifecycle moved into a pool and then an extension (#45521, #45537), and Guardian's subagent-spawner plumbing removed (#45491). Guardian is the reviewer subagent that gates shell, file-write, network and MCP calls; a configurable prompt template means teams can encode their own risk policy in the auto-approve path rather than accepting OpenAI's.