⚠️ Codex CLI 0.154.0 Can Stop Your AI Coding Agent From Launching — The 5-Second Check Before You Upgrade

Tutorials & Methods
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:warning: Codex CLI 0.154.0 can stop your AI coding agent from launching — the 5-second check that tells you before it happens

What this is about: Codex CLI is OpenAI’s coding agent that runs in your terminal. People who self-host wire it to their own proxy, scripts or tool servers. Update 0.154.0 (9 Sep 2026) quietly deletes one command those wirings sometimes call — codex mcp-server — and after the update the agent stops launching with no message about why.

The prize: one line in your terminal, five seconds, and you know upgrade or hold. Both answers come with their command below.

:magnifying_glass_tilted_right: CHECK

rg -n --hidden 'codex[[:space:]]+mcp-server' ~/.local/bin ~/.config ~/.codex 2>/dev/null

:green_circle: Empty output → upgrade: npm install -g @openai/[email protected]
:red_circle: Any match → hold, repoint that launcher, then upgrade
:fast_reverse_button: Broke anyway → npm install -g @openai/[email protected], then fully restart Codex

:compass: Running Codex through a custom OpenAI-compatible proxy? The removal does not touch you. Pin the provider and model in config anyway — 0.154.0 makes fresh and forked sessions fall back to server defaults when nothing is pinned.

🧾 The other 12 changes in 0.154.0 — the 2 red ones bite self-hosters

:red_circle: Fresh sessions and forks fall back to server model defaults when no model is explicitly selected — pin it.
:red_circle: A rejected MCP tool call is not replayed after re-authentication — your controller has to retry it, or the job looks stalled.

:white_circle: Existing sessions discover newly installed plugin tools
:white_circle: Skills and hooks refresh after plugin upgrades or rollbacks
:white_circle: MCP OAuth refresh is coordinated; login challenges are surfaced
:white_circle: Remote resumes and forks preserve saved permissions
:white_circle: Approval authorization survives compaction more reliably
:white_circle: Approvals invalidated by later instructions are rejected
:white_circle: A session open in another app shows a read-only transcript and retries without losing the draft
:white_circle: Isolated Git worktrees via --worktree and /worktree (experimental)
:white_circle: Codex version is included in command and turn metadata

Official notes: Codex changelog

✅ Pre-upgrade checklist for production boxes

☐ codex --version recorded
☐ effective config + session data backed up — rollback is not a backup
☐ the grep above run over every launcher and service
☐ provider, model and reasoning level of production sessions written down
☐ fresh, resumed and forked sessions resolve to the intended model
☐ MCP auth expiry + manual retry tested
☐ a test plugin upgraded and rolled back with a session open
☐ approvals tested before and after compaction
☐ /worktree tried only in a disposable repo
☐ rollback rehearsed on copied session data — worktrees written under 0.154.0 are one-way

Shared so nobody gets paged for a removed command. — Mikey_LikesIT / BCBC

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