Codex CLI 0.151.0: MCP discovery grace period and extension interception of MCP results
OpenAI
Codex CLI stable 0.151.0 (Aug 29) adds a configurable grace period for discovering tools from optional MCP servers and lets extensions inspect or replace MCP tool results before they reach the model. Fixes include preserving restored permission profiles across TUI turns and preventing /cd from weakening sandbox restrictions; several 0.152.0 alphas followed the same day.
Why it matters
Interception of MCP tool results gives Codex a local policy/inspection layer over external tools — a pattern other agents are likely to copy.
Importance: 2/5
minor version with substantive new MCP capabilities