diff --git a/.claude/settings.json b/.claude/settings.json
index 621eaf16..46c844c3 100644
--- a/.claude/settings.json
+++ b/.claude/settings.json
@@ -34,6 +34,15 @@
             "command": "\"$CLAUDE_PROJECT_DIR\"/hooks/tdd-pretool-check.sh"
           }
         ]
+      },
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "\"$CLAUDE_PROJECT_DIR\"/hooks/codex-gate-check.sh"
+          }
+        ]
       }
     ],
     "InstructionsLoaded": [
diff --git a/cli/init.js b/cli/init.js
index ff493221..c95132e2 100644
--- a/cli/init.js
+++ b/cli/init.js
@@ -26,6 +26,7 @@ const FILES = [
   { src: 'hooks/model-effort-check.sh', dest: '.claude/hooks/model-effort-check.sh', executable: true, base: REPO_ROOT },
   { src: 'hooks/precompact-seam-check.sh', dest: '.claude/hooks/precompact-seam-check.sh', executable: true, base: REPO_ROOT },
   { src: 'hooks/goal-confidence-check.sh', dest: '.claude/hooks/goal-confidence-check.sh', executable: true, base: REPO_ROOT },
+  { src: 'hooks/codex-gate-check.sh', dest: '.claude/hooks/codex-gate-check.sh', executable: true, base: REPO_ROOT },
   // #254 Bug 1: shared helper sourced by all hooks above. Must ship — without
   // it, hooks emit "_find-sdlc-root.sh: No such file or directory" + the
   // SDLC root walk-up logic is silently dead.
diff --git a/cli/templates/settings.json b/cli/templates/settings.json
index 74061efe..1d69e18e 100644
--- a/cli/templates/settings.json
+++ b/cli/templates/settings.json
@@ -25,6 +25,15 @@
             "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/tdd-pretool-check.sh"
           }
         ]
+      },
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/codex-gate-check.sh"
+          }
+        ]
       }
     ],
     "InstructionsLoaded": [
diff --git a/hooks/codex-gate-check.sh b/hooks/codex-gate-check.sh
new file mode 100755
index 00000000..fa774a15
--- /dev/null
+++ b/hooks/codex-gate-check.sh
@@ -0,0 +1,39 @@
+#!/bin/bash
+# PreToolUse hook — blocks git commit without cross-model review artifact
+# Fires on Bash tool; only acts when the command contains "git commit"
+
+set -e
+
+# Skip gate if explicitly overridden (emergency bypass with logged justification)
+[ "${CODEX_GATE_SKIP:-}" = "1" ] && exit 0
+
+TOOL_INPUT=$(cat)
+
+COMMAND=$(printf '%s' "$TOOL_INPUT" \
+    | grep -o '"command"[[:space:]]*:[[:space:]]*"[^"]*"' \
+    | head -1 \
+    | sed 's/"command"[[:space:]]*:[[:space:]]*"//; s/"$//')
+
+case "$COMMAND" in
+    *"git commit"*) ;;
+    *) exit 0 ;;
+esac
+
+REVIEW_FILE=".reviews/handoff.json"
+
+if [ ! -f "$REVIEW_FILE" ]; then
+    echo "CROSS-MODEL REVIEW REQUIRED: No .reviews/handoff.json found. Run Codex cross-model review before committing. Set CODEX_GATE_SKIP=1 to bypass with justification."
+    exit 0
+fi
+
+STATUS=$(grep -o '"status"[[:space:]]*:[[:space:]]*"[^"]*"' "$REVIEW_FILE" \
+    | head -1 \
+    | sed 's/.*"status"[[:space:]]*:[[:space:]]*"//; s/"$//')
+
+case "$STATUS" in
+    CERTIFIED|REVIEWED) exit 0 ;;
+    *)
+        echo "CROSS-MODEL REVIEW REQUIRED: .reviews/handoff.json status is '$STATUS' (need REVIEWED or CERTIFIED). Run Codex cross-model review before committing. Set CODEX_GATE_SKIP=1 to bypass with justification."
+        exit 0
+        ;;
+esac
diff --git a/tests/test-hooks.sh b/tests/test-hooks.sh
index c37d9564..e7319eed 100755
--- a/tests/test-hooks.sh
+++ b/tests/test-hooks.sh
@@ -3541,6 +3541,103 @@ test_goal_confidence_check_silent_when_confidence_present
 test_goal_confidence_check_dlc_binding_warning
 test_goal_confidence_check_silent_on_status_and_clear
 
+# ---- codex-gate-check.sh tests ----
+echo ""
+echo "--- codex-gate-check.sh ---"
+
+test_codex_gate_blocks_commit_without_review() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    mkdir -p "$tmpdir"
+    # No .reviews/handoff.json — should block
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git commit -m \"fix: something\""}}' | (cd "$tmpdir" && "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if echo "$out" | grep -qi "cross-model review"; then
+        pass "codex gate blocks commit without review artifact"
+    else
+        fail "codex gate should block commit without review artifact (got: $out)"
+    fi
+}
+
+test_codex_gate_allows_commit_with_certified_review() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    mkdir -p "$tmpdir/.reviews"
+    printf '{"status":"CERTIFIED","score":9}' > "$tmpdir/.reviews/handoff.json"
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git commit -m \"fix: something\""}}' | (cd "$tmpdir" && "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if [ -z "$out" ]; then
+        pass "codex gate allows commit with CERTIFIED review"
+    else
+        fail "codex gate should be silent with CERTIFIED review (got: $out)"
+    fi
+}
+
+test_codex_gate_allows_commit_with_reviewed_status() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    mkdir -p "$tmpdir/.reviews"
+    printf '{"status":"REVIEWED"}' > "$tmpdir/.reviews/handoff.json"
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git commit -m \"fix: something\""}}' | (cd "$tmpdir" && "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if [ -z "$out" ]; then
+        pass "codex gate allows commit with REVIEWED status"
+    else
+        fail "codex gate should be silent with REVIEWED review (got: $out)"
+    fi
+}
+
+test_codex_gate_silent_on_non_commit_commands() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git status"}}' | (cd "$tmpdir" && "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if [ -z "$out" ]; then
+        pass "codex gate silent on non-commit commands"
+    else
+        fail "codex gate should be silent on git status (got: $out)"
+    fi
+}
+
+test_codex_gate_blocks_on_invalid_status() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    mkdir -p "$tmpdir/.reviews"
+    printf '{"status":"PENDING"}' > "$tmpdir/.reviews/handoff.json"
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git commit -m \"fix: thing\""}}' | (cd "$tmpdir" && "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if echo "$out" | grep -qi "cross-model review"; then
+        pass "codex gate blocks commit with PENDING status"
+    else
+        fail "codex gate should block with non-certified status (got: $out)"
+    fi
+}
+
+test_codex_gate_skip_override() {
+    local tmpdir
+    tmpdir=$(mktemp -d)
+    local out
+    out=$(printf '%s' '{"tool_input":{"command":"git commit -m \"fix: something\""}}' | (cd "$tmpdir" && CODEX_GATE_SKIP=1 "$HOOKS_DIR/codex-gate-check.sh") 2>&1) || true
+    rm -rf "$tmpdir"
+    if [ -z "$out" ]; then
+        pass "codex gate respects CODEX_GATE_SKIP=1 override"
+    else
+        fail "codex gate should be silent with CODEX_GATE_SKIP=1 (got: $out)"
+    fi
+}
+
+test_codex_gate_blocks_commit_without_review
+test_codex_gate_allows_commit_with_certified_review
+test_codex_gate_allows_commit_with_reviewed_status
+test_codex_gate_silent_on_non_commit_commands
+test_codex_gate_blocks_on_invalid_status
+test_codex_gate_skip_override
+
 echo ""
 echo "=== Results ==="
 echo "Passed: $PASSED"