diff --git a/api/onboarding.py b/api/onboarding.py
index f09651c4..d2be6d50 100644
--- a/api/onboarding.py
+++ b/api/onboarding.py
@@ -71,7 +71,9 @@ _SUPPORTED_PROVIDER_SETUPS = {
         "default_model": "anthropic/claude-sonnet-4.6",
         "requires_base_url": False,
         "models": [
-            {"id": _to_openrouter_namespace(model["id"]), "label": model["label"]}
+            {"id": "z-ai/glm-4.5-air", "label": "GLM-4.5 Air (free)"}
+            if model["id"] == "zai/glm-4.5-flash"
+            else {"id": _to_openrouter_namespace(model["id"]), "label": model["label"]}
             for model in _FALLBACK_MODELS
         ],
         "category": "easy_start",
diff --git a/tests/test_onboarding_mvp.py b/tests/test_onboarding_mvp.py
index 664fe220..f15a9663 100644
--- a/tests/test_onboarding_mvp.py
+++ b/tests/test_onboarding_mvp.py
@@ -249,3 +249,37 @@ def test_onboarding_setup_rejects_api_key_with_newline():
     )
     assert status == 400
     assert "newline" in data["error"].lower()
+
+
+# ── Regression: #7520 ────────────────────────────────────────────────────────
+
+def test_openrouter_wizard_no_dead_zai_ids():
+    """OpenRouter wizard must not offer zai/glm-4.5-flash — OpenRouter does not
+    serve it.  The free-tier equivalent is z-ai/glm-4.5-air.  (#7520)"""
+    from api.onboarding import _SUPPORTED_PROVIDER_SETUPS
+
+    or_setup = _SUPPORTED_PROVIDER_SETUPS["openrouter"]
+    or_ids = {m["id"] for m in or_setup["models"]}
+
+    # Dead id must not appear in the OpenRouter projection
+    assert "zai/glm-4.5-flash" not in or_ids, (
+        "OpenRouter wizard still offers dead id zai/glm-4.5-flash"
+    )
+    # The remapped replacement must be present
+    assert "z-ai/glm-4.5-air" in or_ids, (
+        "OpenRouter wizard missing remapped z-ai/glm-4.5-air"
+    )
+
+
+def test_zai_native_still_has_glm_4_5_flash():
+    """The native Z.AI onboarding setup must still offer glm-4.5-flash —
+    the remapping is OpenRouter-only."""
+    from api.onboarding import _SUPPORTED_PROVIDER_SETUPS
+
+    zai_setup = _SUPPORTED_PROVIDER_SETUPS["zai"]
+    zai_ids = {m["id"] for m in zai_setup["models"]}
+
+    assert "glm-4.5-flash" in zai_ids, (
+        "Native Z.AI setup lost glm-4.5-flash — the remapping must be "
+        "OpenRouter-only, not touching _FALLBACK_MODELS"
+    )