diff --git a/codex/SKILL.md b/codex/SKILL.md
index e90ec7e89e..26c4b8a984 100644
--- a/codex/SKILL.md
+++ b/codex/SKILL.md
@@ -843,7 +843,9 @@ _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo"
 cd "$_REPO_ROOT"
 # Fix 1: wrap with timeout. 330s (5.5min) is slightly longer than the Bash 300s
 # so the shell wrapper only fires if Bash's own timeout doesn't.
-_gstack_codex_timeout_wrapper 330 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+_gstack_codex_timeout_wrapper 330 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.
+
+Review the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 _CODEX_EXIT=$?
 if [ "$_CODEX_EXIT" = "124" ]; then
   _gstack_codex_log_event "codex_timeout" "330"
@@ -861,7 +863,9 @@ _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo"
 cd "$_REPO_ROOT"
 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.
 
-focus on security" --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+Review the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes.
+
+focus on security" -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 3. Capture the output. Then parse cost from stderr:
diff --git a/codex/SKILL.md.tmpl b/codex/SKILL.md.tmpl
index c311fc80b7..77f1bffb9f 100644
--- a/codex/SKILL.md.tmpl
+++ b/codex/SKILL.md.tmpl
@@ -152,7 +152,9 @@ _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo"
 cd "$_REPO_ROOT"
 # Fix 1: wrap with timeout. 330s (5.5min) is slightly longer than the Bash 300s
 # so the shell wrapper only fires if Bash's own timeout doesn't.
-_gstack_codex_timeout_wrapper 330 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+_gstack_codex_timeout_wrapper 330 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.
+
+Review the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 _CODEX_EXIT=$?
 if [ "$_CODEX_EXIT" = "124" ]; then
   _gstack_codex_log_event "codex_timeout" "330"
@@ -170,7 +172,9 @@ _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo"
 cd "$_REPO_ROOT"
 codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.
 
-focus on security" --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+Review the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes.
+
+focus on security" -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 3. Capture the output. Then parse cost from stderr:
diff --git a/review/SKILL.md b/review/SKILL.md
index f21a401213..27c60af78b 100644
--- a/review/SKILL.md
+++ b/review/SKILL.md
@@ -1521,7 +1521,7 @@ If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
diff --git a/scripts/resolvers/review.ts b/scripts/resolvers/review.ts
index a0f29e1746..ef159df043 100644
--- a/scripts/resolvers/review.ts
+++ b/scripts/resolvers/review.ts
@@ -487,7 +487,7 @@ If \`DIFF_TOTAL >= 200\` AND Codex is available AND \`OLD_CFG\` is NOT \`disable
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "${CODEX_BOUNDARY}Review the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+codex review "${CODEX_BOUNDARY}Review the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 \`\`\`
 
 Set the Bash tool's \`timeout\` parameter to \`300000\` (5 minutes). Do NOT use the \`timeout\` shell command — it doesn't exist on macOS. Present output under \`CODEX SAYS (code review):\` header.
diff --git a/ship/SKILL.md b/ship/SKILL.md
index 1030ef9938..68cef7643e 100644
--- a/ship/SKILL.md
+++ b/ship/SKILL.md
@@ -2247,7 +2247,7 @@ If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
diff --git a/test/fixtures/golden-ship-claude.md b/test/fixtures/golden-ship-claude.md
index 05fff9871b..29bd21b1b8 100644
--- a/test/fixtures/golden-ship-claude.md
+++ b/test/fixtures/golden-ship-claude.md
@@ -2050,7 +2050,7 @@ If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
+codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached 2>"$TMPERR"
 ```
 
 Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
diff --git a/test/fixtures/golden/claude-ship-SKILL.md b/test/fixtures/golden/claude-ship-SKILL.md
index 1030ef9938..68cef7643e 100644
--- a/test/fixtures/golden/claude-ship-SKILL.md
+++ b/test/fixtures/golden/claude-ship-SKILL.md
@@ -2247,7 +2247,7 @@ If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
diff --git a/test/fixtures/golden/factory-ship-SKILL.md b/test/fixtures/golden/factory-ship-SKILL.md
index c361b59cba..fa10107271 100644
--- a/test/fixtures/golden/factory-ship-SKILL.md
+++ b/test/fixtures/golden/factory-ship-SKILL.md
@@ -2238,7 +2238,7 @@ If `DIFF_TOTAL >= 200` AND Codex is available AND `OLD_CFG` is NOT `disabled`:
 TMPERR=$(mktemp /tmp/codex-review-XXXXXXXX)
 _REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
 cd "$_REPO_ROOT"
-codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .factory/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the diff against the base branch." --base <base> -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
+codex review "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .factory/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.\n\nReview the changes on this branch against the base branch <base>. Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD to see the diff and review only those changes." -c 'model_reasoning_effort="high"' --enable web_search_cached < /dev/null 2>"$TMPERR"
 ```
 
 Set the Bash tool's `timeout` parameter to `300000` (5 minutes). Do NOT use the `timeout` shell command — it doesn't exist on macOS. Present output under `CODEX SAYS (code review):` header.
diff --git a/test/gen-skill-docs.test.ts b/test/gen-skill-docs.test.ts
index 4c20343581..6fb4c852e4 100644
--- a/test/gen-skill-docs.test.ts
+++ b/test/gen-skill-docs.test.ts
@@ -2674,6 +2674,22 @@ describe('codex commands must not use inline $(git rev-parse --show-toplevel) fo
     }
     expect(violations).toEqual([]);
   });
+
+  test('codex review commands pass diff scope through prompt, not --base', () => {
+    const checkedFiles = [
+      'codex/SKILL.md.tmpl',
+      'codex/SKILL.md',
+      'scripts/resolvers/review.ts',
+      'review/SKILL.md',
+      'ship/SKILL.md',
+    ];
+
+    for (const rel of checkedFiles) {
+      const content = fs.readFileSync(path.join(ROOT, rel), 'utf-8');
+      expect(content).not.toContain('--base <base> -c \'model_reasoning_effort="high"\'');
+      expect(content).toContain('Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD');
+    }
+  });
 });
 
 // ─── Learnings + Confidence Resolver Tests ─────────────────────
diff --git a/test/skill-validation.test.ts b/test/skill-validation.test.ts
index 24e5e8badc..6936d88fce 100644
--- a/test/skill-validation.test.ts
+++ b/test/skill-validation.test.ts
@@ -1400,6 +1400,14 @@ describe('Codex skill', () => {
     expect(content).toContain('codex exec');
   });
 
+  test('codex review invocations avoid the prompt plus --base argument shape', () => {
+    for (const rel of ['codex/SKILL.md', 'review/SKILL.md', 'ship/SKILL.md']) {
+      const content = fs.readFileSync(path.join(ROOT, rel), 'utf-8');
+      expect(content).not.toContain('--base <base> -c \'model_reasoning_effort="high"\'');
+      expect(content).toContain('Run git diff origin/<base>...HEAD 2>/dev/null || git diff <base>...HEAD');
+    }
+  });
+
   test('/review persists a review-log entry for ship readiness', () => {
     const content = fs.readFileSync(path.join(ROOT, 'review', 'SKILL.md'), 'utf-8');
     expect(content).toContain('"skill":"review"');