diff --git a/scripts/sync_cost_map.py b/scripts/sync_cost_map.py
index bd75cb2000a..50f85eee64f 100644
--- a/scripts/sync_cost_map.py
+++ b/scripts/sync_cost_map.py
@@ -36,6 +36,7 @@ OPENROUTER_MODELS_URL: Final = "https://openrouter.ai/api/v1/models"
 VERCEL_MODELS_URL: Final = "https://ai-gateway.vercel.sh/v1/models"
 VERCEL_TYPE_TO_MODE: Final = MappingProxyType({"language": "chat", "embedding": "embedding"})
 ADD_ONLY_FIELDS: Final = frozenset({"max_output_tokens", "max_tokens"})
+PR_BODY_SECTION_LIMIT: Final = 30
 
 Provider = Literal["openrouter", "vercel_ai_gateway"]
 RegistryEntry = dict[str, object]
@@ -385,8 +386,11 @@ def _ordered_result(cost_map: CostMap, result: CostMap, outcomes: Sequence[Provi
 
 
 def _section_block(title: str, lines: Sequence[str], backtick: bool) -> str:
-    bullets: Final = "\n".join(f"- `{line}`" if backtick else f"- {line}" for line in lines) or "- none"
-    return f"### {title} ({len(lines)})\n{bullets}\n"
+    shown: Final = lines[:PR_BODY_SECTION_LIMIT]
+    bullets: Final = "\n".join(f"- `{line}`" if backtick else f"- {line}" for line in shown) or "- none"
+    overflow: Final = len(lines) - len(shown)
+    trailer: Final = f"\n- and {overflow} more, see the diff" if overflow else ""
+    return f"### {title} ({len(lines)})\n{bullets}{trailer}\n"
 
 
 def _provider_body(outcome: ProviderOutcome) -> str:
diff --git a/tests/test_litellm/test_sync_cost_map.py b/tests/test_litellm/test_sync_cost_map.py
index eb758d24a83..54946ac86dc 100644
--- a/tests/test_litellm/test_sync_cost_map.py
+++ b/tests/test_litellm/test_sync_cost_map.py
@@ -264,6 +264,23 @@ def test_pr_body_lists_changes_per_provider(sync: ModuleType) -> None:
     assert "Catalog rows skipped: deprecated (1), no usable price (1), not token priced (1)" in body
 
 
+def test_pr_body_caps_every_section_so_a_large_first_sync_fits_github_limit(sync: ModuleType) -> None:
+    lines: Final = tuple(f"provider/model-{index}: {'x' * 200}" for index in range(400))
+    outcome: Final = sync.SyncOutcome(
+        cost_map={},
+        providers=tuple(
+            sync.ProviderOutcome(provider=provider, added=lines, updated=lines, warnings=lines, skipped={})
+            for provider in ("openrouter", "vercel_ai_gateway")
+        ),
+    )
+
+    body: Final = sync.render_pr_body(outcome)
+
+    assert len(body) < 65_536
+    assert body.count("### Added (400)") == 2 and body.count("- and 370 more, see the diff") == 6
+    assert body.count("- `provider/model-29: ") == 4 and "provider/model-30: " not in body
+
+
 @pytest.mark.parametrize(
     ("loader", "raw"),
     [