diff --git a/extensions/google/oauth.credentials.ts b/extensions/google/oauth.credentials.ts
new file mode 100644
index 00000000000..1c1e88db042
--- /dev/null
+++ b/extensions/google/oauth.credentials.ts
@@ -0,0 +1,163 @@
+import { existsSync, readFileSync, readdirSync, realpathSync } from "node:fs";
+import { delimiter, dirname, join } from "node:path";
+import { CLIENT_ID_KEYS, CLIENT_SECRET_KEYS } from "./oauth.shared.js";
+
+function resolveEnv(keys: string[]): string | undefined {
+  for (const key of keys) {
+    const value = process.env[key]?.trim();
+    if (value) {
+      return value;
+    }
+  }
+  return undefined;
+}
+
+let cachedGeminiCliCredentials: { clientId: string; clientSecret: string } | null = null;
+
+export function clearCredentialsCache(): void {
+  cachedGeminiCliCredentials = null;
+}
+
+export function extractGeminiCliCredentials(): { clientId: string; clientSecret: string } | null {
+  if (cachedGeminiCliCredentials) {
+    return cachedGeminiCliCredentials;
+  }
+
+  try {
+    const geminiPath = findInPath("gemini");
+    if (!geminiPath) {
+      return null;
+    }
+
+    const resolvedPath = realpathSync(geminiPath);
+    const geminiCliDirs = resolveGeminiCliDirs(geminiPath, resolvedPath);
+
+    let content: string | null = null;
+    for (const geminiCliDir of geminiCliDirs) {
+      const searchPaths = [
+        join(
+          geminiCliDir,
+          "node_modules",
+          "@google",
+          "gemini-cli-core",
+          "dist",
+          "src",
+          "code_assist",
+          "oauth2.js",
+        ),
+        join(
+          geminiCliDir,
+          "node_modules",
+          "@google",
+          "gemini-cli-core",
+          "dist",
+          "code_assist",
+          "oauth2.js",
+        ),
+      ];
+
+      for (const path of searchPaths) {
+        if (existsSync(path)) {
+          content = readFileSync(path, "utf8");
+          break;
+        }
+      }
+      if (content) {
+        break;
+      }
+      const found = findFile(geminiCliDir, "oauth2.js", 10);
+      if (found) {
+        content = readFileSync(found, "utf8");
+        break;
+      }
+    }
+    if (!content) {
+      return null;
+    }
+
+    const idMatch = content.match(/(\d+-[a-z0-9]+\.apps\.googleusercontent\.com)/);
+    const secretMatch = content.match(/(GOCSPX-[A-Za-z0-9_-]+)/);
+    if (idMatch && secretMatch) {
+      cachedGeminiCliCredentials = { clientId: idMatch[1], clientSecret: secretMatch[1] };
+      return cachedGeminiCliCredentials;
+    }
+  } catch {
+    // Gemini CLI not installed or extraction failed
+  }
+  return null;
+}
+
+function resolveGeminiCliDirs(geminiPath: string, resolvedPath: string): string[] {
+  const binDir = dirname(geminiPath);
+  const candidates = [
+    dirname(dirname(resolvedPath)),
+    join(dirname(resolvedPath), "node_modules", "@google", "gemini-cli"),
+    join(binDir, "node_modules", "@google", "gemini-cli"),
+    join(dirname(binDir), "node_modules", "@google", "gemini-cli"),
+    join(dirname(binDir), "lib", "node_modules", "@google", "gemini-cli"),
+  ];
+
+  const deduped: string[] = [];
+  const seen = new Set<string>();
+  for (const candidate of candidates) {
+    const key =
+      process.platform === "win32" ? candidate.replace(/\\/g, "/").toLowerCase() : candidate;
+    if (seen.has(key)) {
+      continue;
+    }
+    seen.add(key);
+    deduped.push(candidate);
+  }
+  return deduped;
+}
+
+function findInPath(name: string): string | null {
+  const exts = process.platform === "win32" ? [".cmd", ".bat", ".exe", ""] : [""];
+  for (const dir of (process.env.PATH ?? "").split(delimiter)) {
+    for (const ext of exts) {
+      const path = join(dir, name + ext);
+      if (existsSync(path)) {
+        return path;
+      }
+    }
+  }
+  return null;
+}
+
+function findFile(dir: string, name: string, depth: number): string | null {
+  if (depth <= 0) {
+    return null;
+  }
+  try {
+    for (const entry of readdirSync(dir, { withFileTypes: true })) {
+      const path = join(dir, entry.name);
+      if (entry.isFile() && entry.name === name) {
+        return path;
+      }
+      if (entry.isDirectory() && !entry.name.startsWith(".")) {
+        const found = findFile(path, name, depth - 1);
+        if (found) {
+          return found;
+        }
+      }
+    }
+  } catch {}
+  return null;
+}
+
+export function resolveOAuthClientConfig(): { clientId: string; clientSecret?: string } {
+  const envClientId = resolveEnv(CLIENT_ID_KEYS);
+  const envClientSecret = resolveEnv(CLIENT_SECRET_KEYS);
+  if (envClientId) {
+    return { clientId: envClientId, clientSecret: envClientSecret };
+  }
+
+  const extracted = extractGeminiCliCredentials();
+  if (extracted) {
+    return extracted;
+  }
+
+  throw new Error(
+    "Gemini CLI not found. Install it first: brew install gemini-cli (or npm install -g @google/gemini-cli), or set GEMINI_CLI_OAUTH_CLIENT_ID.",
+  );
+}
diff --git a/extensions/google/oauth.flow.ts b/extensions/google/oauth.flow.ts
new file mode 100644
index 00000000000..00cab07dc68
--- /dev/null
+++ b/extensions/google/oauth.flow.ts
@@ -0,0 +1,152 @@
+import { createHash, randomBytes } from "node:crypto";
+import { createServer } from "node:http";
+import { isWSL2Sync } from "../../src/infra/wsl.js";
+import { resolveOAuthClientConfig } from "./oauth.credentials.js";
+import { AUTH_URL, REDIRECT_URI, SCOPES } from "./oauth.shared.js";
+
+export function shouldUseManualOAuthFlow(isRemote: boolean): boolean {
+  return isRemote || isWSL2Sync();
+}
+
+export function generatePkce(): { verifier: string; challenge: string } {
+  const verifier = randomBytes(32).toString("hex");
+  const challenge = createHash("sha256").update(verifier).digest("base64url");
+  return { verifier, challenge };
+}
+
+export function buildAuthUrl(challenge: string, verifier: string): string {
+  const { clientId } = resolveOAuthClientConfig();
+  const params = new URLSearchParams({
+    client_id: clientId,
+    response_type: "code",
+    redirect_uri: REDIRECT_URI,
+    scope: SCOPES.join(" "),
+    code_challenge: challenge,
+    code_challenge_method: "S256",
+    state: verifier,
+    access_type: "offline",
+    prompt: "consent",
+  });
+  return `${AUTH_URL}?${params.toString()}`;
+}
+
+export function parseCallbackInput(
+  input: string,
+  expectedState: string,
+): { code: string; state: string } | { error: string } {
+  const trimmed = input.trim();
+  if (!trimmed) {
+    return { error: "No input provided" };
+  }
+
+  try {
+    const url = new URL(trimmed);
+    const code = url.searchParams.get("code");
+    const state = url.searchParams.get("state") ?? expectedState;
+    if (!code) {
+      return { error: "Missing 'code' parameter in URL" };
+    }
+    if (!state) {
+      return { error: "Missing 'state' parameter. Paste the full URL." };
+    }
+    return { code, state };
+  } catch {
+    if (!expectedState) {
+      return { error: "Paste the full redirect URL, not just the code." };
+    }
+    return { code: trimmed, state: expectedState };
+  }
+}
+
+export async function waitForLocalCallback(params: {
+  expectedState: string;
+  timeoutMs: number;
+  onProgress?: (message: string) => void;
+}): Promise<{ code: string; state: string }> {
+  const port = 8085;
+  const hostname = "localhost";
+  const expectedPath = "/oauth2callback";
+
+  return new Promise<{ code: string; state: string }>((resolve, reject) => {
+    let timeout: NodeJS.Timeout | null = null;
+    const server = createServer((req, res) => {
+      try {
+        const requestUrl = new URL(req.url ?? "/", `http://${hostname}:${port}`);
+        if (requestUrl.pathname !== expectedPath) {
+          res.statusCode = 404;
+          res.setHeader("Content-Type", "text/plain");
+          res.end("Not found");
+          return;
+        }
+
+        const error = requestUrl.searchParams.get("error");
+        const code = requestUrl.searchParams.get("code")?.trim();
+        const state = requestUrl.searchParams.get("state")?.trim();
+
+        if (error) {
+          res.statusCode = 400;
+          res.setHeader("Content-Type", "text/plain");
+          res.end(`Authentication failed: ${error}`);
+          finish(new Error(`OAuth error: ${error}`));
+          return;
+        }
+
+        if (!code || !state) {
+          res.statusCode = 400;
+          res.setHeader("Content-Type", "text/plain");
+          res.end("Missing code or state");
+          finish(new Error("Missing OAuth code or state"));
+          return;
+        }
+
+        if (state !== params.expectedState) {
+          res.statusCode = 400;
+          res.setHeader("Content-Type", "text/plain");
+          res.end("Invalid state");
+          finish(new Error("OAuth state mismatch"));
+          return;
+        }
+
+        res.statusCode = 200;
+        res.setHeader("Content-Type", "text/html; charset=utf-8");
+        res.end(
+          "<!doctype html><html><head><meta charset='utf-8'/></head>" +
+            "<body><h2>Gemini CLI OAuth complete</h2>" +
+            "<p>You can close this window and return to OpenClaw.</p></body></html>",
+        );
+
+        finish(undefined, { code, state });
+      } catch (err) {
+        finish(err instanceof Error ? err : new Error("OAuth callback failed"));
+      }
+    });
+
+    const finish = (err?: Error, result?: { code: string; state: string }) => {
+      if (timeout) {
+        clearTimeout(timeout);
+      }
+      try {
+        server.close();
+      } catch {
+        // ignore close errors
+      }
+      if (err) {
+        reject(err);
+      } else if (result) {
+        resolve(result);
+      }
+    };
+
+    server.once("error", (err) => {
+      finish(err instanceof Error ? err : new Error("OAuth callback server error"));
+    });
+
+    server.listen(port, hostname, () => {
+      params.onProgress?.(`Waiting for OAuth callback on ${REDIRECT_URI}…`);
+    });
+
+    timeout = setTimeout(() => {
+      finish(new Error("OAuth callback timeout"));
+    }, params.timeoutMs);
+  });
+}
diff --git a/extensions/google/oauth.http.ts b/extensions/google/oauth.http.ts
new file mode 100644
index 00000000000..6c07c447143
--- /dev/null
+++ b/extensions/google/oauth.http.ts
@@ -0,0 +1,24 @@
+import { fetchWithSsrFGuard } from "../../src/infra/net/fetch-guard.js";
+import { DEFAULT_FETCH_TIMEOUT_MS } from "./oauth.shared.js";
+
+export async function fetchWithTimeout(
+  url: string,
+  init: RequestInit,
+  timeoutMs = DEFAULT_FETCH_TIMEOUT_MS,
+): Promise<Response> {
+  const { response, release } = await fetchWithSsrFGuard({
+    url,
+    init,
+    timeoutMs,
+  });
+  try {
+    const body = await response.arrayBuffer();
+    return new Response(body, {
+      status: response.status,
+      statusText: response.statusText,
+      headers: response.headers,
+    });
+  } finally {
+    await release();
+  }
+}
diff --git a/extensions/google/oauth.project.ts b/extensions/google/oauth.project.ts
new file mode 100644
index 00000000000..fa163b12f19
--- /dev/null
+++ b/extensions/google/oauth.project.ts
@@ -0,0 +1,235 @@
+import { fetchWithTimeout } from "./oauth.http.js";
+import {
+  CODE_ASSIST_ENDPOINT_PROD,
+  LOAD_CODE_ASSIST_ENDPOINTS,
+  TIER_FREE,
+  TIER_LEGACY,
+  TIER_STANDARD,
+  USERINFO_URL,
+} from "./oauth.shared.js";
+
+function resolvePlatform(): "WINDOWS" | "MACOS" | "PLATFORM_UNSPECIFIED" {
+  if (process.platform === "win32") {
+    return "WINDOWS";
+  }
+  if (process.platform === "darwin") {
+    return "MACOS";
+  }
+  return "PLATFORM_UNSPECIFIED";
+}
+
+async function getUserEmail(accessToken: string): Promise<string | undefined> {
+  try {
+    const response = await fetchWithTimeout(USERINFO_URL, {
+      headers: { Authorization: `Bearer ${accessToken}` },
+    });
+    if (response.ok) {
+      const data = (await response.json()) as { email?: string };
+      return data.email;
+    }
+  } catch {
+    // ignore
+  }
+  return undefined;
+}
+
+function isVpcScAffected(payload: unknown): boolean {
+  if (!payload || typeof payload !== "object") {
+    return false;
+  }
+  const error = (payload as { error?: unknown }).error;
+  if (!error || typeof error !== "object") {
+    return false;
+  }
+  const details = (error as { details?: unknown[] }).details;
+  if (!Array.isArray(details)) {
+    return false;
+  }
+  return details.some(
+    (item) =>
+      typeof item === "object" &&
+      item &&
+      (item as { reason?: string }).reason === "SECURITY_POLICY_VIOLATED",
+  );
+}
+
+function getDefaultTier(
+  allowedTiers?: Array<{ id?: string; isDefault?: boolean }>,
+): { id?: string } | undefined {
+  if (!allowedTiers?.length) {
+    return { id: TIER_LEGACY };
+  }
+  return allowedTiers.find((tier) => tier.isDefault) ?? { id: TIER_LEGACY };
+}
+
+async function pollOperation(
+  endpoint: string,
+  operationName: string,
+  headers: Record<string, string>,
+): Promise<{ done?: boolean; response?: { cloudaicompanionProject?: { id?: string } } }> {
+  for (let attempt = 0; attempt < 24; attempt += 1) {
+    await new Promise((resolve) => setTimeout(resolve, 5000));
+    const response = await fetchWithTimeout(`${endpoint}/v1internal/${operationName}`, {
+      headers,
+    });
+    if (!response.ok) {
+      continue;
+    }
+    const data = (await response.json()) as {
+      done?: boolean;
+      response?: { cloudaicompanionProject?: { id?: string } };
+    };
+    if (data.done) {
+      return data;
+    }
+  }
+  throw new Error("Operation polling timeout");
+}
+
+export async function resolveGoogleOAuthIdentity(accessToken: string): Promise<{
+  email?: string;
+  projectId: string;
+}> {
+  const email = await getUserEmail(accessToken);
+  const projectId = await discoverProject(accessToken);
+  return { email, projectId };
+}
+
+async function discoverProject(accessToken: string): Promise<string> {
+  const envProject = process.env.GOOGLE_CLOUD_PROJECT || process.env.GOOGLE_CLOUD_PROJECT_ID;
+  const platform = resolvePlatform();
+  const metadata = {
+    ideType: "ANTIGRAVITY",
+    platform,
+    pluginType: "GEMINI",
+  };
+  const headers = {
+    Authorization: `Bearer ${accessToken}`,
+    "Content-Type": "application/json",
+    "User-Agent": "google-api-nodejs-client/9.15.1",
+    "X-Goog-Api-Client": `gl-node/${process.versions.node}`,
+    "Client-Metadata": JSON.stringify(metadata),
+  };
+
+  const loadBody = {
+    ...(envProject ? { cloudaicompanionProject: envProject } : {}),
+    metadata: {
+      ...metadata,
+      ...(envProject ? { duetProject: envProject } : {}),
+    },
+  };
+
+  let data: {
+    currentTier?: { id?: string };
+    cloudaicompanionProject?: string | { id?: string };
+    allowedTiers?: Array<{ id?: string; isDefault?: boolean }>;
+  } = {};
+  let activeEndpoint = CODE_ASSIST_ENDPOINT_PROD;
+  let loadError: Error | undefined;
+  for (const endpoint of LOAD_CODE_ASSIST_ENDPOINTS) {
+    try {
+      const response = await fetchWithTimeout(`${endpoint}/v1internal:loadCodeAssist`, {
+        method: "POST",
+        headers,
+        body: JSON.stringify(loadBody),
+      });
+
+      if (!response.ok) {
+        const errorPayload = await response.json().catch(() => null);
+        if (isVpcScAffected(errorPayload)) {
+          data = { currentTier: { id: TIER_STANDARD } };
+          activeEndpoint = endpoint;
+          loadError = undefined;
+          break;
+        }
+        loadError = new Error(`loadCodeAssist failed: ${response.status} ${response.statusText}`);
+        continue;
+      }
+
+      data = (await response.json()) as typeof data;
+      activeEndpoint = endpoint;
+      loadError = undefined;
+      break;
+    } catch (err) {
+      loadError = err instanceof Error ? err : new Error("loadCodeAssist failed", { cause: err });
+    }
+  }
+
+  const hasLoadCodeAssistData =
+    Boolean(data.currentTier) ||
+    Boolean(data.cloudaicompanionProject) ||
+    Boolean(data.allowedTiers?.length);
+  if (!hasLoadCodeAssistData && loadError) {
+    if (envProject) {
+      return envProject;
+    }
+    throw loadError;
+  }
+
+  if (data.currentTier) {
+    const project = data.cloudaicompanionProject;
+    if (typeof project === "string" && project) {
+      return project;
+    }
+    if (typeof project === "object" && project?.id) {
+      return project.id;
+    }
+    if (envProject) {
+      return envProject;
+    }
+    throw new Error(
+      "This account requires GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID to be set.",
+    );
+  }
+
+  const tier = getDefaultTier(data.allowedTiers);
+  const tierId = tier?.id || TIER_FREE;
+  if (tierId !== TIER_FREE && !envProject) {
+    throw new Error(
+      "This account requires GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID to be set.",
+    );
+  }
+
+  const onboardBody: Record<string, unknown> = {
+    tierId,
+    metadata: {
+      ...metadata,
+    },
+  };
+  if (tierId !== TIER_FREE && envProject) {
+    onboardBody.cloudaicompanionProject = envProject;
+    (onboardBody.metadata as Record<string, unknown>).duetProject = envProject;
+  }
+
+  const onboardResponse = await fetchWithTimeout(`${activeEndpoint}/v1internal:onboardUser`, {
+    method: "POST",
+    headers,
+    body: JSON.stringify(onboardBody),
+  });
+
+  if (!onboardResponse.ok) {
+    throw new Error(`onboardUser failed: ${onboardResponse.status} ${onboardResponse.statusText}`);
+  }
+
+  let lro = (await onboardResponse.json()) as {
+    done?: boolean;
+    name?: string;
+    response?: { cloudaicompanionProject?: { id?: string } };
+  };
+
+  if (!lro.done && lro.name) {
+    lro = await pollOperation(activeEndpoint, lro.name, headers);
+  }
+
+  const projectId = lro.response?.cloudaicompanionProject?.id;
+  if (projectId) {
+    return projectId;
+  }
+  if (envProject) {
+    return envProject;
+  }
+
+  throw new Error(
+    "Could not discover or provision a Google Cloud project. Set GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID.",
+  );
+}
diff --git a/extensions/google/oauth.shared.ts b/extensions/google/oauth.shared.ts
new file mode 100644
index 00000000000..2b8186737a2
--- /dev/null
+++ b/extensions/google/oauth.shared.ts
@@ -0,0 +1,44 @@
+export const CLIENT_ID_KEYS = ["OPENCLAW_GEMINI_OAUTH_CLIENT_ID", "GEMINI_CLI_OAUTH_CLIENT_ID"];
+export const CLIENT_SECRET_KEYS = [
+  "OPENCLAW_GEMINI_OAUTH_CLIENT_SECRET",
+  "GEMINI_CLI_OAUTH_CLIENT_SECRET",
+];
+export const REDIRECT_URI = "http://localhost:8085/oauth2callback";
+export const AUTH_URL = "https://accounts.google.com/o/oauth2/v2/auth";
+export const TOKEN_URL = "https://oauth2.googleapis.com/token";
+export const USERINFO_URL = "https://www.googleapis.com/oauth2/v1/userinfo?alt=json";
+export const CODE_ASSIST_ENDPOINT_PROD = "https://cloudcode-pa.googleapis.com";
+export const CODE_ASSIST_ENDPOINT_DAILY = "https://daily-cloudcode-pa.sandbox.googleapis.com";
+export const CODE_ASSIST_ENDPOINT_AUTOPUSH = "https://autopush-cloudcode-pa.sandbox.googleapis.com";
+export const LOAD_CODE_ASSIST_ENDPOINTS = [
+  CODE_ASSIST_ENDPOINT_PROD,
+  CODE_ASSIST_ENDPOINT_DAILY,
+  CODE_ASSIST_ENDPOINT_AUTOPUSH,
+];
+export const DEFAULT_FETCH_TIMEOUT_MS = 10_000;
+export const SCOPES = [
+  "https://www.googleapis.com/auth/cloud-platform",
+  "https://www.googleapis.com/auth/userinfo.email",
+  "https://www.googleapis.com/auth/userinfo.profile",
+];
+
+export const TIER_FREE = "free-tier";
+export const TIER_LEGACY = "legacy-tier";
+export const TIER_STANDARD = "standard-tier";
+
+export type GeminiCliOAuthCredentials = {
+  access: string;
+  refresh: string;
+  expires: number;
+  email?: string;
+  projectId: string;
+};
+
+export type GeminiCliOAuthContext = {
+  isRemote: boolean;
+  openUrl: (url: string) => Promise<void>;
+  log: (msg: string) => void;
+  note: (message: string, title?: string) => Promise<void>;
+  prompt: (message: string) => Promise<string>;
+  progress: { update: (msg: string) => void; stop: (msg?: string) => void };
+};
diff --git a/extensions/google/oauth.token.ts b/extensions/google/oauth.token.ts
new file mode 100644
index 00000000000..6e2b68c4403
--- /dev/null
+++ b/extensions/google/oauth.token.ts
@@ -0,0 +1,57 @@
+import { resolveOAuthClientConfig } from "./oauth.credentials.js";
+import { fetchWithTimeout } from "./oauth.http.js";
+import { resolveGoogleOAuthIdentity } from "./oauth.project.js";
+import { REDIRECT_URI, TOKEN_URL, type GeminiCliOAuthCredentials } from "./oauth.shared.js";
+
+export async function exchangeCodeForTokens(
+  code: string,
+  verifier: string,
+): Promise<GeminiCliOAuthCredentials> {
+  const { clientId, clientSecret } = resolveOAuthClientConfig();
+  const body = new URLSearchParams({
+    client_id: clientId,
+    code,
+    grant_type: "authorization_code",
+    redirect_uri: REDIRECT_URI,
+    code_verifier: verifier,
+  });
+  if (clientSecret) {
+    body.set("client_secret", clientSecret);
+  }
+
+  const response = await fetchWithTimeout(TOKEN_URL, {
+    method: "POST",
+    headers: {
+      "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8",
+      Accept: "*/*",
+      "User-Agent": "google-api-nodejs-client/9.15.1",
+    },
+    body,
+  });
+
+  if (!response.ok) {
+    const errorText = await response.text();
+    throw new Error(`Token exchange failed: ${errorText}`);
+  }
+
+  const data = (await response.json()) as {
+    access_token: string;
+    refresh_token: string;
+    expires_in: number;
+  };
+
+  if (!data.refresh_token) {
+    throw new Error("No refresh token received. Please try again.");
+  }
+
+  const identity = await resolveGoogleOAuthIdentity(data.access_token);
+  const expiresAt = Date.now() + data.expires_in * 1000 - 5 * 60 * 1000;
+
+  return {
+    refresh: data.refresh_token,
+    access: data.access_token,
+    expires: expiresAt,
+    projectId: identity.projectId,
+    email: identity.email,
+  };
+}
diff --git a/extensions/google/oauth.ts b/extensions/google/oauth.ts
index 5932b3a237b..be12c64a4e1 100644
--- a/extensions/google/oauth.ts
+++ b/extensions/google/oauth.ts
@@ -1,661 +1,16 @@
-import { createHash, randomBytes } from "node:crypto";
-import { existsSync, readFileSync, readdirSync, realpathSync } from "node:fs";
-import { createServer } from "node:http";
-import { delimiter, dirname, join } from "node:path";
-import { fetchWithSsrFGuard } from "../../src/infra/net/fetch-guard.js";
-import { isWSL2Sync } from "../../src/infra/wsl.js";
-
-const CLIENT_ID_KEYS = ["OPENCLAW_GEMINI_OAUTH_CLIENT_ID", "GEMINI_CLI_OAUTH_CLIENT_ID"];
-const CLIENT_SECRET_KEYS = [
-  "OPENCLAW_GEMINI_OAUTH_CLIENT_SECRET",
-  "GEMINI_CLI_OAUTH_CLIENT_SECRET",
-];
-const REDIRECT_URI = "http://localhost:8085/oauth2callback";
-const AUTH_URL = "https://accounts.google.com/o/oauth2/v2/auth";
-const TOKEN_URL = "https://oauth2.googleapis.com/token";
-const USERINFO_URL = "https://www.googleapis.com/oauth2/v1/userinfo?alt=json";
-const CODE_ASSIST_ENDPOINT_PROD = "https://cloudcode-pa.googleapis.com";
-const CODE_ASSIST_ENDPOINT_DAILY = "https://daily-cloudcode-pa.sandbox.googleapis.com";
-const CODE_ASSIST_ENDPOINT_AUTOPUSH = "https://autopush-cloudcode-pa.sandbox.googleapis.com";
-const LOAD_CODE_ASSIST_ENDPOINTS = [
-  CODE_ASSIST_ENDPOINT_PROD,
-  CODE_ASSIST_ENDPOINT_DAILY,
-  CODE_ASSIST_ENDPOINT_AUTOPUSH,
-];
-const DEFAULT_FETCH_TIMEOUT_MS = 10_000;
-const SCOPES = [
-  "https://www.googleapis.com/auth/cloud-platform",
-  "https://www.googleapis.com/auth/userinfo.email",
-  "https://www.googleapis.com/auth/userinfo.profile",
-];
-
-const TIER_FREE = "free-tier";
-const TIER_LEGACY = "legacy-tier";
-const TIER_STANDARD = "standard-tier";
-
-export type GeminiCliOAuthCredentials = {
-  access: string;
-  refresh: string;
-  expires: number;
-  email?: string;
-  projectId: string;
-};
-
-export type GeminiCliOAuthContext = {
-  isRemote: boolean;
-  openUrl: (url: string) => Promise<void>;
-  log: (msg: string) => void;
-  note: (message: string, title?: string) => Promise<void>;
-  prompt: (message: string) => Promise<string>;
-  progress: { update: (msg: string) => void; stop: (msg?: string) => void };
-};
-
-function resolveEnv(keys: string[]): string | undefined {
-  for (const key of keys) {
-    const value = process.env[key]?.trim();
-    if (value) {
-      return value;
-    }
-  }
-  return undefined;
-}
-
-let cachedGeminiCliCredentials: { clientId: string; clientSecret: string } | null = null;
-
-/** @internal */
-export function clearCredentialsCache(): void {
-  cachedGeminiCliCredentials = null;
-}
-
-/** Extracts OAuth credentials from the installed Gemini CLI's bundled oauth2.js. */
-export function extractGeminiCliCredentials(): { clientId: string; clientSecret: string } | null {
-  if (cachedGeminiCliCredentials) {
-    return cachedGeminiCliCredentials;
-  }
-
-  try {
-    const geminiPath = findInPath("gemini");
-    if (!geminiPath) {
-      return null;
-    }
-
-    const resolvedPath = realpathSync(geminiPath);
-    const geminiCliDirs = resolveGeminiCliDirs(geminiPath, resolvedPath);
-
-    let content: string | null = null;
-    for (const geminiCliDir of geminiCliDirs) {
-      const searchPaths = [
-        join(
-          geminiCliDir,
-          "node_modules",
-          "@google",
-          "gemini-cli-core",
-          "dist",
-          "src",
-          "code_assist",
-          "oauth2.js",
-        ),
-        join(
-          geminiCliDir,
-          "node_modules",
-          "@google",
-          "gemini-cli-core",
-          "dist",
-          "code_assist",
-          "oauth2.js",
-        ),
-      ];
-
-      for (const p of searchPaths) {
-        if (existsSync(p)) {
-          content = readFileSync(p, "utf8");
-          break;
-        }
-      }
-      if (content) {
-        break;
-      }
-      const found = findFile(geminiCliDir, "oauth2.js", 10);
-      if (found) {
-        content = readFileSync(found, "utf8");
-        break;
-      }
-    }
-    if (!content) {
-      return null;
-    }
-
-    const idMatch = content.match(/(\d+-[a-z0-9]+\.apps\.googleusercontent\.com)/);
-    const secretMatch = content.match(/(GOCSPX-[A-Za-z0-9_-]+)/);
-    if (idMatch && secretMatch) {
-      cachedGeminiCliCredentials = { clientId: idMatch[1], clientSecret: secretMatch[1] };
-      return cachedGeminiCliCredentials;
-    }
-  } catch {
-    // Gemini CLI not installed or extraction failed
-  }
-  return null;
-}
-
-function resolveGeminiCliDirs(geminiPath: string, resolvedPath: string): string[] {
-  const binDir = dirname(geminiPath);
-  const candidates = [
-    dirname(dirname(resolvedPath)),
-    join(dirname(resolvedPath), "node_modules", "@google", "gemini-cli"),
-    join(binDir, "node_modules", "@google", "gemini-cli"),
-    join(dirname(binDir), "node_modules", "@google", "gemini-cli"),
-    join(dirname(binDir), "lib", "node_modules", "@google", "gemini-cli"),
-  ];
-
-  const deduped: string[] = [];
-  const seen = new Set<string>();
-  for (const candidate of candidates) {
-    const key =
-      process.platform === "win32" ? candidate.replace(/\\/g, "/").toLowerCase() : candidate;
-    if (seen.has(key)) {
-      continue;
-    }
-    seen.add(key);
-    deduped.push(candidate);
-  }
-  return deduped;
-}
-
-function findInPath(name: string): string | null {
-  const exts = process.platform === "win32" ? [".cmd", ".bat", ".exe", ""] : [""];
-  for (const dir of (process.env.PATH ?? "").split(delimiter)) {
-    for (const ext of exts) {
-      const p = join(dir, name + ext);
-      if (existsSync(p)) {
-        return p;
-      }
-    }
-  }
-  return null;
-}
-
-function findFile(dir: string, name: string, depth: number): string | null {
-  if (depth <= 0) {
-    return null;
-  }
-  try {
-    for (const e of readdirSync(dir, { withFileTypes: true })) {
-      const p = join(dir, e.name);
-      if (e.isFile() && e.name === name) {
-        return p;
-      }
-      if (e.isDirectory() && !e.name.startsWith(".")) {
-        const found = findFile(p, name, depth - 1);
-        if (found) {
-          return found;
-        }
-      }
-    }
-  } catch {}
-  return null;
-}
-
-function resolveOAuthClientConfig(): { clientId: string; clientSecret?: string } {
-  // 1. Check env vars first (user override)
-  const envClientId = resolveEnv(CLIENT_ID_KEYS);
-  const envClientSecret = resolveEnv(CLIENT_SECRET_KEYS);
-  if (envClientId) {
-    return { clientId: envClientId, clientSecret: envClientSecret };
-  }
-
-  // 2. Try to extract from installed Gemini CLI
-  const extracted = extractGeminiCliCredentials();
-  if (extracted) {
-    return extracted;
-  }
-
-  // 3. No credentials available
-  throw new Error(
-    "Gemini CLI not found. Install it first: brew install gemini-cli (or npm install -g @google/gemini-cli), or set GEMINI_CLI_OAUTH_CLIENT_ID.",
-  );
-}
-
-function shouldUseManualOAuthFlow(isRemote: boolean): boolean {
-  return isRemote || isWSL2Sync();
-}
-
-function generatePkce(): { verifier: string; challenge: string } {
-  const verifier = randomBytes(32).toString("hex");
-  const challenge = createHash("sha256").update(verifier).digest("base64url");
-  return { verifier, challenge };
-}
-
-function resolvePlatform(): "WINDOWS" | "MACOS" | "PLATFORM_UNSPECIFIED" {
-  if (process.platform === "win32") {
-    return "WINDOWS";
-  }
-  if (process.platform === "darwin") {
-    return "MACOS";
-  }
-  // Google's loadCodeAssist API rejects "LINUX" as an invalid Platform enum value.
-  // Use "PLATFORM_UNSPECIFIED" for Linux and other platforms to match the pi-ai runtime.
-  return "PLATFORM_UNSPECIFIED";
-}
-
-async function fetchWithTimeout(
-  url: string,
-  init: RequestInit,
-  timeoutMs = DEFAULT_FETCH_TIMEOUT_MS,
-): Promise<Response> {
-  const { response, release } = await fetchWithSsrFGuard({
-    url,
-    init,
-    timeoutMs,
-  });
-  try {
-    const body = await response.arrayBuffer();
-    return new Response(body, {
-      status: response.status,
-      statusText: response.statusText,
-      headers: response.headers,
-    });
-  } finally {
-    await release();
-  }
-}
-
-function buildAuthUrl(challenge: string, verifier: string): string {
-  const { clientId } = resolveOAuthClientConfig();
-  const params = new URLSearchParams({
-    client_id: clientId,
-    response_type: "code",
-    redirect_uri: REDIRECT_URI,
-    scope: SCOPES.join(" "),
-    code_challenge: challenge,
-    code_challenge_method: "S256",
-    state: verifier,
-    access_type: "offline",
-    prompt: "consent",
-  });
-  return `${AUTH_URL}?${params.toString()}`;
-}
-
-function parseCallbackInput(
-  input: string,
-  expectedState: string,
-): { code: string; state: string } | { error: string } {
-  const trimmed = input.trim();
-  if (!trimmed) {
-    return { error: "No input provided" };
-  }
-
-  try {
-    const url = new URL(trimmed);
-    const code = url.searchParams.get("code");
-    const state = url.searchParams.get("state") ?? expectedState;
-    if (!code) {
-      return { error: "Missing 'code' parameter in URL" };
-    }
-    if (!state) {
-      return { error: "Missing 'state' parameter. Paste the full URL." };
-    }
-    return { code, state };
-  } catch {
-    if (!expectedState) {
-      return { error: "Paste the full redirect URL, not just the code." };
-    }
-    return { code: trimmed, state: expectedState };
-  }
-}
-
-async function waitForLocalCallback(params: {
-  expectedState: string;
-  timeoutMs: number;
-  onProgress?: (message: string) => void;
-}): Promise<{ code: string; state: string }> {
-  const port = 8085;
-  const hostname = "localhost";
-  const expectedPath = "/oauth2callback";
-
-  return new Promise<{ code: string; state: string }>((resolve, reject) => {
-    let timeout: NodeJS.Timeout | null = null;
-    const server = createServer((req, res) => {
-      try {
-        const requestUrl = new URL(req.url ?? "/", `http://${hostname}:${port}`);
-        if (requestUrl.pathname !== expectedPath) {
-          res.statusCode = 404;
-          res.setHeader("Content-Type", "text/plain");
-          res.end("Not found");
-          return;
-        }
-
-        const error = requestUrl.searchParams.get("error");
-        const code = requestUrl.searchParams.get("code")?.trim();
-        const state = requestUrl.searchParams.get("state")?.trim();
-
-        if (error) {
-          res.statusCode = 400;
-          res.setHeader("Content-Type", "text/plain");
-          res.end(`Authentication failed: ${error}`);
-          finish(new Error(`OAuth error: ${error}`));
-          return;
-        }
-
-        if (!code || !state) {
-          res.statusCode = 400;
-          res.setHeader("Content-Type", "text/plain");
-          res.end("Missing code or state");
-          finish(new Error("Missing OAuth code or state"));
-          return;
-        }
-
-        if (state !== params.expectedState) {
-          res.statusCode = 400;
-          res.setHeader("Content-Type", "text/plain");
-          res.end("Invalid state");
-          finish(new Error("OAuth state mismatch"));
-          return;
-        }
-
-        res.statusCode = 200;
-        res.setHeader("Content-Type", "text/html; charset=utf-8");
-        res.end(
-          "<!doctype html><html><head><meta charset='utf-8'/></head>" +
-            "<body><h2>Gemini CLI OAuth complete</h2>" +
-            "<p>You can close this window and return to OpenClaw.</p></body></html>",
-        );
-
-        finish(undefined, { code, state });
-      } catch (err) {
-        finish(err instanceof Error ? err : new Error("OAuth callback failed"));
-      }
-    });
-
-    const finish = (err?: Error, result?: { code: string; state: string }) => {
-      if (timeout) {
-        clearTimeout(timeout);
-      }
-      try {
-        server.close();
-      } catch {
-        // ignore close errors
-      }
-      if (err) {
-        reject(err);
-      } else if (result) {
-        resolve(result);
-      }
-    };
-
-    server.once("error", (err) => {
-      finish(err instanceof Error ? err : new Error("OAuth callback server error"));
-    });
-
-    server.listen(port, hostname, () => {
-      params.onProgress?.(`Waiting for OAuth callback on ${REDIRECT_URI}…`);
-    });
-
-    timeout = setTimeout(() => {
-      finish(new Error("OAuth callback timeout"));
-    }, params.timeoutMs);
-  });
-}
-
-async function exchangeCodeForTokens(
-  code: string,
-  verifier: string,
-): Promise<GeminiCliOAuthCredentials> {
-  const { clientId, clientSecret } = resolveOAuthClientConfig();
-  const body = new URLSearchParams({
-    client_id: clientId,
-    code,
-    grant_type: "authorization_code",
-    redirect_uri: REDIRECT_URI,
-    code_verifier: verifier,
-  });
-  if (clientSecret) {
-    body.set("client_secret", clientSecret);
-  }
-
-  const response = await fetchWithTimeout(TOKEN_URL, {
-    method: "POST",
-    headers: {
-      "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8",
-      Accept: "*/*",
-      "User-Agent": "google-api-nodejs-client/9.15.1",
-    },
-    body,
-  });
-
-  if (!response.ok) {
-    const errorText = await response.text();
-    throw new Error(`Token exchange failed: ${errorText}`);
-  }
-
-  const data = (await response.json()) as {
-    access_token: string;
-    refresh_token: string;
-    expires_in: number;
-  };
-
-  if (!data.refresh_token) {
-    throw new Error("No refresh token received. Please try again.");
-  }
-
-  const email = await getUserEmail(data.access_token);
-  const projectId = await discoverProject(data.access_token);
-  const expiresAt = Date.now() + data.expires_in * 1000 - 5 * 60 * 1000;
-
-  return {
-    refresh: data.refresh_token,
-    access: data.access_token,
-    expires: expiresAt,
-    projectId,
-    email,
-  };
-}
-
-async function getUserEmail(accessToken: string): Promise<string | undefined> {
-  try {
-    const response = await fetchWithTimeout(USERINFO_URL, {
-      headers: { Authorization: `Bearer ${accessToken}` },
-    });
-    if (response.ok) {
-      const data = (await response.json()) as { email?: string };
-      return data.email;
-    }
-  } catch {
-    // ignore
-  }
-  return undefined;
-}
-
-async function discoverProject(accessToken: string): Promise<string> {
-  const envProject = process.env.GOOGLE_CLOUD_PROJECT || process.env.GOOGLE_CLOUD_PROJECT_ID;
-  const platform = resolvePlatform();
-  const metadata = {
-    ideType: "ANTIGRAVITY",
-    platform,
-    pluginType: "GEMINI",
-  };
-  const headers = {
-    Authorization: `Bearer ${accessToken}`,
-    "Content-Type": "application/json",
-    "User-Agent": "google-api-nodejs-client/9.15.1",
-    "X-Goog-Api-Client": `gl-node/${process.versions.node}`,
-    "Client-Metadata": JSON.stringify(metadata),
-  };
-
-  const loadBody = {
-    ...(envProject ? { cloudaicompanionProject: envProject } : {}),
-    metadata: {
-      ...metadata,
-      ...(envProject ? { duetProject: envProject } : {}),
-    },
-  };
-
-  let data: {
-    currentTier?: { id?: string };
-    cloudaicompanionProject?: string | { id?: string };
-    allowedTiers?: Array<{ id?: string; isDefault?: boolean }>;
-  } = {};
-  let activeEndpoint = CODE_ASSIST_ENDPOINT_PROD;
-  let loadError: Error | undefined;
-  for (const endpoint of LOAD_CODE_ASSIST_ENDPOINTS) {
-    try {
-      const response = await fetchWithTimeout(`${endpoint}/v1internal:loadCodeAssist`, {
-        method: "POST",
-        headers,
-        body: JSON.stringify(loadBody),
-      });
-
-      if (!response.ok) {
-        const errorPayload = await response.json().catch(() => null);
-        if (isVpcScAffected(errorPayload)) {
-          data = { currentTier: { id: TIER_STANDARD } };
-          activeEndpoint = endpoint;
-          loadError = undefined;
-          break;
-        }
-        loadError = new Error(`loadCodeAssist failed: ${response.status} ${response.statusText}`);
-        continue;
-      }
-
-      data = (await response.json()) as typeof data;
-      activeEndpoint = endpoint;
-      loadError = undefined;
-      break;
-    } catch (err) {
-      loadError = err instanceof Error ? err : new Error("loadCodeAssist failed", { cause: err });
-    }
-  }
-
-  const hasLoadCodeAssistData =
-    Boolean(data.currentTier) ||
-    Boolean(data.cloudaicompanionProject) ||
-    Boolean(data.allowedTiers?.length);
-  if (!hasLoadCodeAssistData && loadError) {
-    if (envProject) {
-      return envProject;
-    }
-    throw loadError;
-  }
-
-  if (data.currentTier) {
-    const project = data.cloudaicompanionProject;
-    if (typeof project === "string" && project) {
-      return project;
-    }
-    if (typeof project === "object" && project?.id) {
-      return project.id;
-    }
-    if (envProject) {
-      return envProject;
-    }
-    throw new Error(
-      "This account requires GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID to be set.",
-    );
-  }
-
-  const tier = getDefaultTier(data.allowedTiers);
-  const tierId = tier?.id || TIER_FREE;
-  if (tierId !== TIER_FREE && !envProject) {
-    throw new Error(
-      "This account requires GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID to be set.",
-    );
-  }
-
-  const onboardBody: Record<string, unknown> = {
-    tierId,
-    metadata: {
-      ...metadata,
-    },
-  };
-  if (tierId !== TIER_FREE && envProject) {
-    onboardBody.cloudaicompanionProject = envProject;
-    (onboardBody.metadata as Record<string, unknown>).duetProject = envProject;
-  }
-
-  const onboardResponse = await fetchWithTimeout(`${activeEndpoint}/v1internal:onboardUser`, {
-    method: "POST",
-    headers,
-    body: JSON.stringify(onboardBody),
-  });
-
-  if (!onboardResponse.ok) {
-    throw new Error(`onboardUser failed: ${onboardResponse.status} ${onboardResponse.statusText}`);
-  }
-
-  let lro = (await onboardResponse.json()) as {
-    done?: boolean;
-    name?: string;
-    response?: { cloudaicompanionProject?: { id?: string } };
-  };
-
-  if (!lro.done && lro.name) {
-    lro = await pollOperation(activeEndpoint, lro.name, headers);
-  }
-
-  const projectId = lro.response?.cloudaicompanionProject?.id;
-  if (projectId) {
-    return projectId;
-  }
-  if (envProject) {
-    return envProject;
-  }
-
-  throw new Error(
-    "Could not discover or provision a Google Cloud project. Set GOOGLE_CLOUD_PROJECT or GOOGLE_CLOUD_PROJECT_ID.",
-  );
-}
-
-function isVpcScAffected(payload: unknown): boolean {
-  if (!payload || typeof payload !== "object") {
-    return false;
-  }
-  const error = (payload as { error?: unknown }).error;
-  if (!error || typeof error !== "object") {
-    return false;
-  }
-  const details = (error as { details?: unknown[] }).details;
-  if (!Array.isArray(details)) {
-    return false;
-  }
-  return details.some(
-    (item) =>
-      typeof item === "object" &&
-      item &&
-      (item as { reason?: string }).reason === "SECURITY_POLICY_VIOLATED",
-  );
-}
-
-function getDefaultTier(
-  allowedTiers?: Array<{ id?: string; isDefault?: boolean }>,
-): { id?: string } | undefined {
-  if (!allowedTiers?.length) {
-    return { id: TIER_LEGACY };
-  }
-  return allowedTiers.find((tier) => tier.isDefault) ?? { id: TIER_LEGACY };
-}
-
-async function pollOperation(
-  endpoint: string,
-  operationName: string,
-  headers: Record<string, string>,
-): Promise<{ done?: boolean; response?: { cloudaicompanionProject?: { id?: string } } }> {
-  for (let attempt = 0; attempt < 24; attempt += 1) {
-    await new Promise((resolve) => setTimeout(resolve, 5000));
-    const response = await fetchWithTimeout(`${endpoint}/v1internal/${operationName}`, {
-      headers,
-    });
-    if (!response.ok) {
-      continue;
-    }
-    const data = (await response.json()) as {
-      done?: boolean;
-      response?: { cloudaicompanionProject?: { id?: string } };
-    };
-    if (data.done) {
-      return data;
-    }
-  }
-  throw new Error("Operation polling timeout");
-}
+import { clearCredentialsCache, extractGeminiCliCredentials } from "./oauth.credentials.js";
+import {
+  buildAuthUrl,
+  generatePkce,
+  parseCallbackInput,
+  shouldUseManualOAuthFlow,
+  waitForLocalCallback,
+} from "./oauth.flow.js";
+import type { GeminiCliOAuthContext, GeminiCliOAuthCredentials } from "./oauth.shared.js";
+import { exchangeCodeForTokens } from "./oauth.token.js";
+
+export { clearCredentialsCache, extractGeminiCliCredentials };
+export type { GeminiCliOAuthContext, GeminiCliOAuthCredentials };
 
 export async function loginGeminiCliOAuth(
   ctx: GeminiCliOAuthContext,