diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae85fa62472..a7f3f685f3d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -71,6 +71,7 @@ Docs: https://docs.openclaw.ai
 - Daemon/macOS launchd: forward proxy env vars into supervised service environments, keep LaunchAgent `KeepAlive=true` semantics, and harden restart sequencing to `print -> bootout -> wait old pid exit -> bootstrap -> kickstart`. (#27276) thanks @frankekn.
 - Gateway/macOS restart-loop hardening: detect OpenClaw-managed supervisor markers during SIGUSR1 restart handoff, clean stale gateway PIDs before `/restart` launchctl/systemctl triggers, and set LaunchAgent `ThrottleInterval=60` to bound launchd retry storms during lock-release races. Landed from contributor PRs #27655 (@taw0002), #27448 (@Sid-Qin), and #27650 (@kevinWangSheng). (#27605, #27590, #26904, #26736)
 - Models/MiniMax auth header defaults: set `authHeader: true` for both onboarding-generated MiniMax API providers and implicit built-in MiniMax (`minimax`, `minimax-portal`) provider templates so first requests no longer fail with MiniMax `401 authentication_error` due to missing `Authorization` header. Landed from contributor PRs #27622 by @riccoyuanft and #27631 by @kevinWangSheng. (#27600, #15303)
+- Models/Google Antigravity IDs: normalize bare `gemini-3-pro`, `gemini-3.1-pro`, and `gemini-3-1-pro` model IDs to the default `-low` thinking tier so provider requests no longer fail with 404 when the tier suffix is omitted. (#24145) Thanks @byungsker.
 - Auth/Auth profiles: normalize `auth-profiles.json` alias fields (`mode -> type`, `apiKey -> key`) before credential validation so entries copied from `openclaw.json` auth examples are no longer silently dropped. (#26950) thanks @byungsker.
 - Models/Google Gemini: treat `google` (Gemini API key auth profile) as a reasoning-tag provider to prevent `<think>` leakage, and add forward-compat model fallback for `google-gemini-cli` `gemini-3.1-pro*` / `gemini-3.1-flash*` IDs to avoid false unknown-model errors. (#26551, #26524) Thanks @byungsker.
 - Models/Profile suffix parsing: centralize trailing `@profile` parsing and only treat `@` as a profile separator when it appears after the final `/`, preserving model IDs like `openai/@cf/...` and `openrouter/@preset/...` across `/model` directive parsing and allowlist model resolution, with regression coverage.
diff --git a/src/agents/models-config.providers.google-antigravity.test.ts b/src/agents/models-config.providers.google-antigravity.test.ts
new file mode 100644
index 00000000000..51fe5fb32e0
--- /dev/null
+++ b/src/agents/models-config.providers.google-antigravity.test.ts
@@ -0,0 +1,87 @@
+import { mkdtempSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { describe, expect, it } from "vitest";
+import {
+  normalizeAntigravityModelId,
+  normalizeProviders,
+  type ProviderConfig,
+} from "./models-config.providers.js";
+
+function buildModel(id: string): NonNullable<ProviderConfig["models"]>[number] {
+  return {
+    id,
+    name: id,
+    reasoning: true,
+    input: ["text"],
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+    contextWindow: 1,
+    maxTokens: 1,
+  };
+}
+
+function buildProvider(modelIds: string[]): ProviderConfig {
+  return {
+    baseUrl: "https://example.invalid/v1",
+    api: "openai-completions",
+    apiKey: "EXAMPLE_KEY",
+    models: modelIds.map((id) => buildModel(id)),
+  };
+}
+
+describe("normalizeAntigravityModelId", () => {
+  it.each(["gemini-3-pro", "gemini-3.1-pro", "gemini-3-1-pro"])(
+    "adds default -low suffix to bare pro id: %s",
+    (id) => {
+      expect(normalizeAntigravityModelId(id)).toBe(`${id}-low`);
+    },
+  );
+
+  it.each([
+    "gemini-3-pro-low",
+    "gemini-3-pro-high",
+    "gemini-3.1-flash",
+    "claude-opus-4-6-thinking",
+  ])("keeps already-tiered and non-pro ids unchanged: %s", (id) => {
+    expect(normalizeAntigravityModelId(id)).toBe(id);
+  });
+});
+
+describe("google-antigravity provider normalization", () => {
+  it("normalizes bare gemini pro IDs only for google-antigravity providers", () => {
+    const agentDir = mkdtempSync(join(tmpdir(), "openclaw-test-"));
+    const providers = {
+      "google-antigravity": buildProvider([
+        "gemini-3-pro",
+        "gemini-3.1-pro",
+        "gemini-3-1-pro",
+        "gemini-3-pro-high",
+        "claude-opus-4-6-thinking",
+      ]),
+      openai: buildProvider(["gpt-5"]),
+    };
+
+    const normalized = normalizeProviders({ providers, agentDir });
+
+    expect(normalized).not.toBe(providers);
+    expect(normalized?.["google-antigravity"]?.models.map((model) => model.id)).toEqual([
+      "gemini-3-pro-low",
+      "gemini-3.1-pro-low",
+      "gemini-3-1-pro-low",
+      "gemini-3-pro-high",
+      "claude-opus-4-6-thinking",
+    ]);
+    expect(normalized?.openai).toBe(providers.openai);
+  });
+
+  it("returns original providers object when no antigravity IDs need normalization", () => {
+    const agentDir = mkdtempSync(join(tmpdir(), "openclaw-test-"));
+    const providers = {
+      "google-antigravity": buildProvider(["gemini-3-pro-low", "claude-opus-4-6-thinking"]),
+    };
+
+    const normalized = normalizeProviders({ providers, agentDir });
+
+    expect(normalized).toBe(providers);
+  });
+});
diff --git a/src/agents/models-config.providers.ts b/src/agents/models-config.providers.ts
index b4b5d810293..584b340ea11 100644
--- a/src/agents/models-config.providers.ts
+++ b/src/agents/models-config.providers.ts
@@ -391,10 +391,22 @@ export function normalizeGoogleModelId(id: string): string {
   return id;
 }
 
-function normalizeGoogleProvider(provider: ProviderConfig): ProviderConfig {
+const ANTIGRAVITY_BARE_PRO_IDS = new Set(["gemini-3-pro", "gemini-3.1-pro", "gemini-3-1-pro"]);
+
+export function normalizeAntigravityModelId(id: string): string {
+  if (ANTIGRAVITY_BARE_PRO_IDS.has(id)) {
+    return `${id}-low`;
+  }
+  return id;
+}
+
+function normalizeProviderModels(
+  provider: ProviderConfig,
+  normalizeId: (id: string) => string,
+): ProviderConfig {
   let mutated = false;
   const models = provider.models.map((model) => {
-    const nextId = normalizeGoogleModelId(model.id);
+    const nextId = normalizeId(model.id);
     if (nextId === model.id) {
       return model;
     }
@@ -404,6 +416,14 @@ function normalizeGoogleProvider(provider: ProviderConfig): ProviderConfig {
   return mutated ? { ...provider, models } : provider;
 }
 
+function normalizeGoogleProvider(provider: ProviderConfig): ProviderConfig {
+  return normalizeProviderModels(provider, normalizeGoogleModelId);
+}
+
+function normalizeAntigravityProvider(provider: ProviderConfig): ProviderConfig {
+  return normalizeProviderModels(provider, normalizeAntigravityModelId);
+}
+
 export function normalizeProviders(params: {
   providers: ModelsConfig["providers"];
   agentDir: string;
@@ -470,6 +490,14 @@ export function normalizeProviders(params: {
       normalizedProvider = googleNormalized;
     }
 
+    if (normalizedKey === "google-antigravity") {
+      const antigravityNormalized = normalizeAntigravityProvider(normalizedProvider);
+      if (antigravityNormalized !== normalizedProvider) {
+        mutated = true;
+      }
+      normalizedProvider = antigravityNormalized;
+    }
+
     next[key] = normalizedProvider;
   }