diff --git a/changelog.d/fixes/8866-auto-family-classification.md b/changelog.d/fixes/8866-auto-family-classification.md
new file mode 100644
index 0000000000..53ed6d5512
--- /dev/null
+++ b/changelog.d/fixes/8866-auto-family-classification.md
@@ -0,0 +1 @@
+- **Auto routing**: `auto/<family>` combos (`auto/glm`, `auto/gemini`, `auto/llama`, …) are recognized as built-in auto models again — the family suffix failed the category/tier parser and fell through as an unknown model instead of routing to that family
diff --git a/src/sse/handlers/autoRouting.ts b/src/sse/handlers/autoRouting.ts
index 49987dcd08..f898f1094d 100644
--- a/src/sse/handlers/autoRouting.ts
+++ b/src/sse/handlers/autoRouting.ts
@@ -10,13 +10,17 @@ import {
   type AutoCategory,
   type AutoTier,
 } from "@omniroute/open-sse/services/autoCombo/suffixComposition.ts";
+import {
+  isValidModelFamily,
+  type ModelFamily,
+} from "@omniroute/open-sse/services/autoCombo/modelFamily.ts";
 import { getCachedSettings } from "@/lib/localDb";
 import * as log from "../utils/logger";
 
 export type AutoRoutingState = {
   model: string;
   variant?: AutoVariant;
-  spec?: { category?: AutoCategory; tier?: AutoTier };
+  spec?: { category?: AutoCategory; tier?: AutoTier; family?: ModelFamily };
   isAutoRouting: boolean;
   recognizedBuiltInAuto: boolean;
   response: Response | null;
@@ -37,12 +41,19 @@ function classifyAutoModel(
     return { recognizedBuiltInAuto: true };
   }
   const parsedSuffix = parseAutoSuffix(suffix);
-  return parsedSuffix.valid
-    ? {
-        recognizedBuiltInAuto: true,
-        spec: { category: parsedSuffix.category, tier: parsedSuffix.tier },
-      }
-    : { recognizedBuiltInAuto };
+  if (parsedSuffix.valid) {
+    return {
+      recognizedBuiltInAuto: true,
+      spec: { category: parsedSuffix.category, tier: parsedSuffix.tier },
+    };
+  }
+  if (isValidModelFamily(suffix)) {
+    return {
+      recognizedBuiltInAuto: true,
+      spec: { family: suffix as ModelFamily },
+    };
+  }
+  return { recognizedBuiltInAuto };
 }
 
 async function applyAutoPrefix(
diff --git a/tests/unit/auto-family-classification-8866.test.ts b/tests/unit/auto-family-classification-8866.test.ts
new file mode 100644
index 0000000000..f32ecd651f
--- /dev/null
+++ b/tests/unit/auto-family-classification-8866.test.ts
@@ -0,0 +1,50 @@
+/**
+ * #8866 — `auto/<family>` must be recognized as a built-in auto model.
+ *
+ * classifyAutoModel() is module-private, so this exercises it through the public
+ * resolveAutoRoutingState(). Before the fix, a family suffix failed parseAutoSuffix()
+ * and fell through to `recognizedBuiltInAuto: false` with no spec, so `auto/glm` was
+ * treated as an unknown model instead of a family-scoped auto combo.
+ */
+import test from "node:test";
+import assert from "node:assert/strict";
+import { MODEL_FAMILIES } from "@omniroute/open-sse/services/autoCombo/modelFamily.ts";
+import { resolveAutoRoutingState } from "../../src/sse/handlers/autoRouting.ts";
+
+test("#8866: every model family is recognized as auto/<family>", async () => {
+  assert.ok(MODEL_FAMILIES.length > 0, "expected a non-empty family list");
+  for (const family of MODEL_FAMILIES) {
+    const state = await resolveAutoRoutingState(`auto/${family}`);
+    assert.equal(
+      state.recognizedBuiltInAuto,
+      true,
+      `auto/${family} should be a recognized built-in auto model`
+    );
+    assert.equal(state.spec?.family, family, `auto/${family} should carry spec.family`);
+    assert.equal(state.isAutoRouting, true);
+  }
+});
+
+test("#8866: a family suffix does not hijack the category/tier spec", async () => {
+  // A valid category/tier suffix keeps its own shape — the family branch is only a
+  // fallback for suffixes parseAutoSuffix rejects.
+  const state = await resolveAutoRoutingState("auto/coding");
+  assert.equal(state.recognizedBuiltInAuto, true);
+  assert.equal(state.spec?.family, undefined, "auto/coding is a category, not a family");
+});
+
+test("#8866: an unknown suffix stays unrecognized", async () => {
+  const state = await resolveAutoRoutingState("auto/not-a-real-family-xyz");
+  assert.equal(
+    state.recognizedBuiltInAuto,
+    false,
+    "an unknown suffix must not be treated as a built-in auto model"
+  );
+  assert.equal(state.spec?.family, undefined);
+});
+
+test("#8866: a plain model is untouched by the family branch", async () => {
+  const state = await resolveAutoRoutingState("gpt-5.6-sol");
+  assert.equal(state.isAutoRouting, false);
+  assert.equal(state.spec?.family, undefined);
+});