diff --git a/open-sse/config/antigravityModelAliases.ts b/open-sse/config/antigravityModelAliases.ts
index f2713b2832..745249af37 100644
--- a/open-sse/config/antigravityModelAliases.ts
+++ b/open-sse/config/antigravityModelAliases.ts
@@ -1,25 +1,16 @@
 export const ANTIGRAVITY_PUBLIC_MODELS = Object.freeze([
   { id: "claude-opus-4-6-thinking", name: "Claude Opus 4.6 Thinking" },
-  { id: "claude-sonnet-4-6", name: "Claude Sonnet 4.6" },
-  { id: "gemini-3-flash-preview", name: "Gemini 3 Flash Preview" },
-  { id: "gemini-3-pro-preview", name: "Gemini 3 Pro Preview" },
-  { id: "gemini-3-pro-image-preview", name: "Gemini 3 Pro Image Preview" },
+  { id: "claude-sonnet-4-6", name: "Claude Sonnet 4.6 Thinking" },
+  { id: "gemini-3-pro-preview", name: "Gemini 3.1 Pro (High)" },
+  { id: "gemini-3.1-pro-low", name: "Gemini 3.1 Pro (Low)" },
+  { id: "gemini-3-flash-preview", name: "Gemini 3 Flash" },
+  { id: "gpt-oss-120b-medium", name: "GPT OSS 120B Medium" },
+  { id: "gemini-3-pro-image-preview", name: "Gemini 3 Pro Image" },
+  { id: "gemini-3.1-flash-image", name: "Gemini 3.1 Flash Image" },
   {
     id: "gemini-2.5-computer-use-preview-10-2025",
     name: "Gemini 2.5 Computer Use Preview (10/2025)",
   },
-  { id: "gemini-3.1-flash-image", name: "Gemini 3.1 Flash Image" },
-  { id: "gemini-3.1-pro-low", name: "Gemini 3.1 Pro (Low)" },
-  { id: "gemini-claude-sonnet-4-5", name: "Claude Sonnet 4.5 (Gemini Route)" },
-  {
-    id: "gemini-claude-sonnet-4-5-thinking",
-    name: "Claude Sonnet 4.5 Thinking (Gemini Route)",
-  },
-  {
-    id: "gemini-claude-opus-4-5-thinking",
-    name: "Claude Opus 4.5 Thinking (Gemini Route)",
-  },
-  { id: "gpt-oss-120b-medium", name: "GPT OSS 120B Medium" },
 ]);
 
 export const ANTIGRAVITY_MODEL_ALIASES = Object.freeze({
@@ -27,24 +18,19 @@ export const ANTIGRAVITY_MODEL_ALIASES = Object.freeze({
   "gemini-3-flash-preview": "gemini-3-flash",
   "gemini-3-pro-image-preview": "gemini-3-pro-image",
   "gemini-2.5-computer-use-preview-10-2025": "rev19-uic3-1p",
-  "gemini-claude-sonnet-4-5": "claude-sonnet-4-5",
-  "gemini-claude-sonnet-4-5-thinking": "claude-sonnet-4-5-thinking",
-  "gemini-claude-opus-4-5-thinking": "claude-opus-4-5-thinking",
+  "gemini-claude-sonnet-4-5": "claude-sonnet-4-6",
+  "gemini-claude-sonnet-4-5-thinking": "claude-sonnet-4-6",
+  "gemini-claude-opus-4-5-thinking": "claude-opus-4-6-thinking",
 });
 
 type AntigravityModelAliasMap = Record<string, string>;
 
-export const ANTIGRAVITY_REVERSE_MODEL_ALIASES = Object.freeze(
-  Object.entries(ANTIGRAVITY_MODEL_ALIASES).reduce<Record<string, string>>(
-    (acc, [alias, target]) => {
-      if (!acc[target]) {
-        acc[target] = alias;
-      }
-      return acc;
-    },
-    {}
-  )
-);
+export const ANTIGRAVITY_REVERSE_MODEL_ALIASES: AntigravityModelAliasMap = Object.freeze({
+  "gemini-3.1-pro-high": "gemini-3-pro-preview",
+  "gemini-3-flash": "gemini-3-flash-preview",
+  "gemini-3-pro-image": "gemini-3-pro-image-preview",
+  "rev19-uic3-1p": "gemini-2.5-computer-use-preview-10-2025",
+});
 
 const CLIENT_VISIBLE_MODEL_NAMES = Object.freeze(
   ANTIGRAVITY_PUBLIC_MODELS.reduce<Record<string, string>>((acc, model) => {
diff --git a/tests/unit/antigravity-model-aliases.test.ts b/tests/unit/antigravity-model-aliases.test.ts
index 67d1bb9b90..543f9d9c2c 100644
--- a/tests/unit/antigravity-model-aliases.test.ts
+++ b/tests/unit/antigravity-model-aliases.test.ts
@@ -15,14 +15,11 @@ test("resolveAntigravityModelId maps the documented Antigravity aliases to upstr
     resolveAntigravityModelId("gemini-2.5-computer-use-preview-10-2025"),
     "rev19-uic3-1p"
   );
-  assert.equal(resolveAntigravityModelId("gemini-claude-sonnet-4-5"), "claude-sonnet-4-5");
-  assert.equal(
-    resolveAntigravityModelId("gemini-claude-sonnet-4-5-thinking"),
-    "claude-sonnet-4-5-thinking"
-  );
+  assert.equal(resolveAntigravityModelId("gemini-claude-sonnet-4-5"), "claude-sonnet-4-6");
+  assert.equal(resolveAntigravityModelId("gemini-claude-sonnet-4-5-thinking"), "claude-sonnet-4-6");
   assert.equal(
     resolveAntigravityModelId("gemini-claude-opus-4-5-thinking"),
-    "claude-opus-4-5-thinking"
+    "claude-opus-4-6-thinking"
   );
   assert.equal(resolveAntigravityModelId("unknown-model"), "unknown-model");
 });
@@ -31,6 +28,8 @@ test("toClientAntigravityModelId exposes client-visible aliases for known upstre
   assert.equal(toClientAntigravityModelId("gemini-3.1-pro-high"), "gemini-3-pro-preview");
   assert.equal(toClientAntigravityModelId("gemini-3-flash"), "gemini-3-flash-preview");
   assert.equal(toClientAntigravityModelId("gpt-oss-120b-medium"), "gpt-oss-120b-medium");
+  assert.equal(toClientAntigravityModelId("claude-sonnet-4-6"), "claude-sonnet-4-6");
+  assert.equal(toClientAntigravityModelId("claude-opus-4-6-thinking"), "claude-opus-4-6-thinking");
 });
 
 test("AntigravityExecutor.transformRequest resolves alias models before dispatching upstream", async () => {
diff --git a/tests/unit/models-catalog-route.test.ts b/tests/unit/models-catalog-route.test.ts
index 4a7d08feb5..ad2ad9ffe2 100644
--- a/tests/unit/models-catalog-route.test.ts
+++ b/tests/unit/models-catalog-route.test.ts
@@ -305,6 +305,9 @@ test("v1 models catalog exposes Antigravity client-visible preview aliases inste
   assert.ok(ids.has("antigravity/gemini-3-pro-preview"));
   assert.ok(ids.has("antigravity/gemini-3-flash-preview"));
   assert.equal(ids.has("antigravity/gemini-3.1-pro-high"), false);
+  assert.equal(ids.has("antigravity/gemini-claude-sonnet-4-5"), false);
+  assert.equal(ids.has("antigravity/gemini-claude-sonnet-4-5-thinking"), false);
+  assert.equal(ids.has("antigravity/gemini-claude-opus-4-5-thinking"), false);
 });
 
 test("v1 models catalog uses provider-node prefixes for compatible provider custom models", async () => {
diff --git a/tests/unit/t28-model-catalog-updates.test.ts b/tests/unit/t28-model-catalog-updates.test.ts
index 20aa54b3f2..1284dc74a2 100644
--- a/tests/unit/t28-model-catalog-updates.test.ts
+++ b/tests/unit/t28-model-catalog-updates.test.ts
@@ -25,6 +25,9 @@ test("T28: antigravity static catalog exposes client-visible Gemini preview IDs"
   assert.ok(staticIds.includes("gemini-3-flash-preview"));
   assert.ok(!staticIds.includes("gemini-3-pro-high"));
   assert.ok(!staticIds.includes("gemini-3.1-pro-high"));
+  assert.ok(!staticIds.includes("gemini-claude-sonnet-4-5"));
+  assert.ok(!staticIds.includes("gemini-claude-sonnet-4-5-thinking"));
+  assert.ok(!staticIds.includes("gemini-claude-opus-4-5-thinking"));
 });
 
 test("T28: github registry exposes Gemini 3.1 Pro Preview and keeps legacy alias compatibility", async () => {
diff --git a/tests/unit/t31-t33-t34-t38-model-specs.test.ts b/tests/unit/t31-t33-t34-t38-model-specs.test.ts
index f1f60497e7..893c1f0a1d 100644
--- a/tests/unit/t31-t33-t34-t38-model-specs.test.ts
+++ b/tests/unit/t31-t33-t34-t38-model-specs.test.ts
@@ -22,6 +22,9 @@ test("T31: antigravity static catalog exposes client-visible Gemini preview IDs"
   const staticIds = (getStaticModelsForProvider("antigravity") || []).map((m) => m.id);
   assert.ok(staticIds.includes("gemini-3-pro-preview"));
   assert.ok(staticIds.includes("gemini-3.1-pro-low"));
+  assert.ok(!staticIds.includes("gemini-claude-sonnet-4-5"));
+  assert.ok(!staticIds.includes("gemini-claude-sonnet-4-5-thinking"));
+  assert.ok(!staticIds.includes("gemini-claude-opus-4-5-thinking"));
 });
 
 test("T31: legacy Gemini aliases resolve to Gemini 3.1 IDs", () => {