feat: add Grok as a --guest runtime for Claude /codex commands

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Added
+
+- Let `/codex:review`, `/codex:adversarial-review`, `/codex:rescue`, and `/codex:setup` run Grok as the guest via `--guest grok` or `CC_GUEST=grok`. The default guest remains Codex; Grok uses `--prompt-file` plus `--output-format json` and does not inherit Codex model aliases or the Codex app-server.
+
 ## 1.2.0 — 2026-08-28
 
 ### Merged from upstream pull requests

README.md

@@ -90,12 +90,15 @@ Use it when you want:
 
 Use `--base <ref>` for branch review. It also supports `--wait` and `--background`. It is not steerable and does not take custom focus text. Use [`/codex:adversarial-review`](#codexadversarial-review) when you want to challenge a specific decision or risk area.
 
+`--guest` selects the runtime. The default is `codex`. Pass `--guest grok` (or set `CC_GUEST=grok`) to run Grok headless instead of Codex app-server. Grok does not inherit Codex model aliases such as `spark`; omit `--model` to use Grok's default, or pass a Grok model ID.
+
 Examples:
 
 ```bash
 /codex:review
 /codex:review --base main
 /codex:review --background
+/codex:review --guest grok
 ```
 
 This command is read-only and will not perform any changes. When run in the background you can use [`/codex:status`](#codexstatus) to check on the progress and [`/codex:cancel`](#codexcancel) to cancel the ongoing task.

plugins/codex/commands/adversarial-review.md

@@ -1,6 +1,6 @@
 ---
 description: Run a Codex review that challenges the implementation approach and design choices
-argument-hint: '[--wait|--background] [--base <ref>] [--scope auto|working-tree|branch] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value] [focus ...]'
+argument-hint: '[--wait|--background] [--guest <codex|grok>] [--base <ref>] [--scope auto|working-tree|branch] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value] [focus ...]'
 disable-model-invocation: true
 allowed-tools: Read, Glob, Grep, Bash(node:*), Bash(git:*), AskUserQuestion
 ---

plugins/codex/commands/rescue.md

@@ -1,6 +1,6 @@
 ---
 description: Delegate investigation, an explicit fix request, or follow-up rescue work to the Codex rescue subagent
-argument-hint: "[--background] [--resume|--fresh] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value]... [what Codex should investigate, solve, or continue]"
+argument-hint: "[--background] [--guest <codex|grok>] [--resume|--fresh] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value]... [what Codex should investigate, solve, or continue]"
 allowed-tools: Bash(node:*), AskUserQuestion, Agent
 ---
 

plugins/codex/commands/review.md

@@ -1,6 +1,6 @@
 ---
 description: Run a Codex code review against local git state
-argument-hint: '[--wait|--background] [--base <ref>] [--scope auto|working-tree|branch] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value]'
+argument-hint: '[--wait|--background] [--guest <codex|grok>] [--base <ref>] [--scope auto|working-tree|branch] [--model <model|spark|sol|luna|terra|mini>] [--effort <none|minimal|low|medium|high|xhigh|max|ultra>] [--turn-timeout-ms <ms>] [--config key=value]'
 disable-model-invocation: true
 allowed-tools: Read, Glob, Grep, Bash(node:*), Bash(git:*), AskUserQuestion
 ---
@@ -32,7 +32,8 @@ Execution mode rules:
   - `Run in background`
 
 Argument handling:
-- Preserve the user's arguments exactly.
+- Preserve the user's arguments exactly, including `--guest <codex|grok>` (default guest is codex).
+- Do not add `--guest grok` unless the user asked for Grok.
 - Do not strip `--wait` or `--background` yourself.
 - Do not add extra review instructions or rewrite the user's intent.
 - The companion script parses `--wait` and `--background`, but Claude Code's `Bash(..., run_in_background: true)` is what actually detaches the run.

plugins/codex/commands/setup.md

@@ -1,6 +1,6 @@
 ---
 description: Check whether the local Codex CLI is ready and optionally toggle the stop-time review gate
-argument-hint: '[--enable-review-gate|--disable-review-gate]'
+argument-hint: '[--guest <codex|grok>] [--enable-review-gate|--disable-review-gate]'
 allowed-tools: Bash(node:*), Bash(npm:*), AskUserQuestion
 ---