feat(antigravity): overhaul identity, fingerprinting & envelope format

- Add centralized antigravityIdentity service (sessionId, machineId, requestId) - Switch User-Agent to Electron/Chrome desktop format - Reorder upstream URLs: sandbox first, production last - Add runtime headers: x-client-name, x-client-version, x-machine-id, x-vscode-sessionid, x-goog-user-project - Add 403 retry without x-goog-user-project header - Add generation defaults (topK=40, topP=1.0, maxOutputTokens guard) - Strip cache_control from Claude requests recursively - Enterprise/consumer routing via userAgent field (jetski vs antigravity) - Update envelope field order and add enabledCreditTypes - MITM proxy: support multiple target hosts - Version: semver comparison with pickNewestVersion(), bump fallback to 4.1.33 - Update all affected tests
2026-07-26 09:52:11 +03:00 · 2026-05-07 18:14:55 +03:00
parent 08e18867fd
commit f1af90e97e
23 changed files with 458 additions and 138 deletions
--- a/open-sse/config/antigravityUpstream.ts
+++ b/open-sse/config/antigravityUpstream.ts
@@ -1,7 +1,7 @@
 export const ANTIGRAVITY_BASE_URLS = Object.freeze([
-  "https://cloudcode-pa.googleapis.com",
-  "https://daily-cloudcode-pa.googleapis.com",
  "https://daily-cloudcode-pa.sandbox.googleapis.com",
+  "https://daily-cloudcode-pa.googleapis.com",
+  "https://cloudcode-pa.googleapis.com",
 ]);

 const ANTIGRAVITY_MODELS_PATH = "/v1internal:models";
--- a/open-sse/config/cliFingerprints.ts
+++ b/open-sse/config/cliFingerprints.ts
@@ -175,17 +175,22 @@ export const CLI_FINGERPRINTS: Record<string, CliFingerprint> = {
      "Content-Type",
      "Authorization",
      "User-Agent",
+      "x-client-name",
+      "x-client-version",
+      "x-machine-id",
+      "x-vscode-sessionid",
+      "x-goog-user-project",
      "Accept",
      "Accept-Encoding",
    ],
    bodyFieldOrder: [
      "project",
+      "requestId",
+      "request",
      "model",
      "userAgent",
      "requestType",
-      "requestId",
      "enabledCreditTypes",
-      "request",
    ],
    userAgent: getAntigravityUserAgent,
  },
--- a/open-sse/config/constants.ts
+++ b/open-sse/config/constants.ts
@@ -35,7 +35,10 @@ export const CLAUDE_SYSTEM_PROMPT = "You are Claude Code, Anthropic's official C

 // Antigravity default system prompt (required for API to work)
 export const ANTIGRAVITY_DEFAULT_SYSTEM =
-  "Please ignore the following [ignore]You are Antigravity, a powerful agentic AI coding assistant designed by the Google Deepmind team working on Advanced Agentic Coding.You are pair programming with a USER to solve their coding task. The task may require creating a new codebase, modifying or debugging an existing codebase, or simply answering a question.**Absolute paths only****Proactiveness**[/ignore]";
+  "You are Antigravity, a powerful agentic AI coding assistant designed by the Google Deepmind team working on Advanced Agentic Coding.\n" +
+  "You are pair programming with a USER to solve their coding task. The task may require creating a new codebase, modifying or debugging an existing codebase, or simply answering a question.\n" +
+  "**Absolute paths only**\n" +
+  "**Proactiveness**";

 // OAuth endpoints
 export const OAUTH_ENDPOINTS = {
--- a/open-sse/executors/antigravity.ts
+++ b/open-sse/executors/antigravity.ts
@@ -3,7 +3,10 @@ import { BaseExecutor, mergeUpstreamExtraHeaders, type ExecuteInput } from "./ba
 import { applyFingerprint, isCliCompatEnabled } from "../config/cliFingerprints.ts";
 import { PROVIDERS, OAUTH_ENDPOINTS, HTTP_STATUS } from "../config/constants.ts";
 import { scrubProxyAndFingerprintHeaders } from "../services/antigravityHeaderScrub.ts";
-import { antigravityUserAgent } from "../services/antigravityHeaders.ts";
+import {
+  antigravityNativeOAuthUserAgent,
+  antigravityUserAgent,
+} from "../services/antigravityHeaders.ts";
 import { classify429, decide429, type Decision } from "../services/antigravity429Engine.ts";
 import {
  injectCreditsField,
@@ -14,13 +17,23 @@ import {
 } from "../services/antigravityCredits.ts";
 import { persistCreditBalance, getAllPersistedCreditBalances } from "@/lib/db/creditBalance";
 import { obfuscateSensitiveWords } from "../services/antigravityObfuscation.ts";
-import { resolveAntigravityVersion } from "../services/antigravityVersion.ts";
+import {
+  getCachedAntigravityVersion,
+  resolveAntigravityVersion,
+} from "../services/antigravityVersion.ts";
 import { resolveAntigravityModelId } from "../config/antigravityModelAliases.ts";
 import { cloakAntigravityToolPayload } from "../config/toolCloaking.ts";
 import {
  shouldStripCloudCodeThinking,
  stripCloudCodeThinkingConfig,
 } from "../services/cloudCodeThinking.ts";
+import {
+  deriveAntigravityMachineId,
+  generateAntigravityRequestId,
+  getAntigravityEnvelopeUserAgent,
+  getAntigravitySessionId,
+  getAntigravityVscodeSessionId,
+} from "../services/antigravityIdentity.ts";

 const MAX_RETRY_AFTER_MS = 60_000;
 const LONG_RETRY_THRESHOLD_MS = 60_000;
@@ -63,10 +76,11 @@ type AntigravityCollectedStream = {
 type AntigravityRequestEnvelope = Record<string, unknown> & {
  project: string;
  model: string;
-  userAgent: "antigravity";
-  requestType: "agent";
+  userAgent: "antigravity" | "jetski";
+  requestType: "agent" | "image_gen";
  requestId: string;
  request: Record<string, unknown>;
+  enabledCreditTypes?: string[];
 };

 /**
@@ -235,6 +249,70 @@ function getRequestTargetModel(body: Record<string, unknown>): string {
  return typeof target === "string" && target.length > 0 ? target : "unknown";
 }

+function getProjectHeaderValue(body: unknown): string | null {
+  const project =
+    body && typeof body === "object" ? (body as Record<string, unknown>).project : null;
+  if (typeof project !== "string" || project.trim().length === 0) return null;
+  if (project === "test-project" || project === "project-id") return null;
+  return project;
+}
+
+function applyAntigravityRuntimeHeaders(
+  headers: Record<string, string>,
+  credentials: Record<string, unknown> | null | undefined,
+  body: unknown
+): void {
+  headers["User-Agent"] = antigravityUserAgent();
+  headers["x-client-name"] = "antigravity";
+  headers["x-client-version"] = getCachedAntigravityVersion();
+  headers["x-machine-id"] = deriveAntigravityMachineId(credentials);
+  headers["x-vscode-sessionid"] = getAntigravityVscodeSessionId();
+
+  const project = getProjectHeaderValue(body);
+  if (project) {
+    headers["x-goog-user-project"] = project;
+  }
+}
+
+function removeHeaderCaseInsensitive(headers: Record<string, string>, name: string): void {
+  const lowerName = name.toLowerCase();
+  for (const key of Object.keys(headers)) {
+    if (key.toLowerCase() === lowerName) {
+      delete headers[key];
+    }
+  }
+}
+
+function applyAntigravityGenerationDefaults(request: Record<string, unknown>): void {
+  const generationConfig =
+    request.generationConfig && typeof request.generationConfig === "object"
+      ? (request.generationConfig as Record<string, unknown>)
+      : {};
+
+  if (generationConfig.topK === undefined) {
+    generationConfig.topK = 40;
+  }
+  if (generationConfig.topP === undefined) {
+    generationConfig.topP = 1.0;
+  }
+
+  const thinkingConfig =
+    generationConfig.thinkingConfig && typeof generationConfig.thinkingConfig === "object"
+      ? (generationConfig.thinkingConfig as Record<string, unknown>)
+      : null;
+  const thinkingBudget = Number(thinkingConfig?.thinkingBudget);
+  const maxOutputTokens = Number(generationConfig.maxOutputTokens);
+  if (
+    Number.isFinite(thinkingBudget) &&
+    thinkingBudget > 0 &&
+    (!Number.isFinite(maxOutputTokens) || maxOutputTokens <= thinkingBudget)
+  ) {
+    generationConfig.maxOutputTokens = Math.floor(thinkingBudget) + 1;
+  }
+
+  request.generationConfig = generationConfig;
+}
+
 export class AntigravityExecutor extends BaseExecutor {
  constructor() {
    super("antigravity", PROVIDERS.antigravity);
@@ -313,7 +391,7 @@ export class AntigravityExecutor extends BaseExecutor {
      // exactly as generated by openaiToClaudeRequestForAntigravity, without Gemini mappings.
      transformedRequest = {
        ...normalizedBody.request,
-        sessionId: normalizedBody.request?.sessionId || this.generateSessionId(),
+        sessionId: getAntigravitySessionId(credentials, normalizedBody.request?.sessionId),
      };
    } else {
      // Fix contents for Gemini models via Antigravity
@@ -349,7 +427,7 @@ export class AntigravityExecutor extends BaseExecutor {
      transformedRequest = {
        ...normalizedBody.request,
        ...(contents.length > 0 && { contents }),
-        sessionId: normalizedBody.request?.sessionId || this.generateSessionId(),
+        sessionId: getAntigravitySessionId(credentials, normalizedBody.request?.sessionId),
        safetySettings: undefined,
        toolConfig:
          normalizedBody.request?.tools?.length > 0
@@ -372,6 +450,8 @@ export class AntigravityExecutor extends BaseExecutor {
      }
    }

+    applyAntigravityGenerationDefaults(transformedRequest);
+
    const {
      project: _project,
      model: _model,
@@ -382,15 +462,22 @@ export class AntigravityExecutor extends BaseExecutor {
      ...passthroughFields
    } = normalizedBody;

-    return {
+    const requestType = _requestType === "image_gen" ? "image_gen" : "agent";
+    const envelope: AntigravityRequestEnvelope = {
      project: projectId,
-      model: upstreamModel,
-      userAgent: "antigravity",
-      requestType: "agent",
-      requestId: `agent-${crypto.randomUUID()}`,
+      requestId: generateAntigravityRequestId(),
      request: transformedRequest,
+      model: upstreamModel,
+      userAgent: getAntigravityEnvelopeUserAgent(credentials),
+      requestType,
      ...passthroughFields,
    };
+
+    if (requestType === "agent" && envelope.enabledCreditTypes === undefined) {
+      envelope.enabledCreditTypes = ["GOOGLE_ONE_AI"];
+    }
+
+    return envelope;
  }

  async refreshCredentials(credentials, log) {
@@ -402,6 +489,7 @@ export class AntigravityExecutor extends BaseExecutor {
        headers: {
          "Content-Type": "application/x-www-form-urlencoded",
          Accept: "application/json",
+          "User-Agent": antigravityNativeOAuthUserAgent(),
        },
        body: new URLSearchParams({
          grant_type: "refresh_token",
@@ -617,6 +705,8 @@ export class AntigravityExecutor extends BaseExecutor {
        requestToolNameMap = cloaked.toolNameMap;
      }

+      applyAntigravityRuntimeHeaders(headers, credentials, transformedBody);
+
      // Credits-first: inject GOOGLE_ONE_AI upfront so we never try the normal
      // quota path. If credits are exhausted / disabled shouldUseCreditsFirst()
      // returns false and we fall back to the legacy retry-on-429 flow.
@@ -636,20 +726,33 @@ export class AntigravityExecutor extends BaseExecutor {
          headers,
          transformedBody
        );
-        const finalHeaders = serializedRequest.headers;
+        let finalHeaders = serializedRequest.headers;

        log?.debug?.(
          "TELEMETRY",
          `[Antigravity] Execute - URL: ${url}, Model: ${model}, Target: ${getRequestTargetModel(transformedBody)}, RetryAttempt: ${retryAttemptsByUrl[urlIndex]}`
        );

-        const response = await fetch(url, {
+        let response = await fetch(url, {
          method: "POST",
          headers: finalHeaders,
          body: serializedRequest.bodyString,
          signal,
        });

+        if (response.status === HTTP_STATUS.FORBIDDEN && finalHeaders["x-goog-user-project"]) {
+          const retryHeaders = { ...finalHeaders };
+          removeHeaderCaseInsensitive(retryHeaders, "x-goog-user-project");
+          log?.debug?.("RETRY", "403 with x-goog-user-project, retrying once without it");
+          response = await fetch(url, {
+            method: "POST",
+            headers: retryHeaders,
+            body: serializedRequest.bodyString,
+            signal,
+          });
+          finalHeaders = retryHeaders;
+        }
+
        if (!response.ok) {
          log?.warn?.(
            "TELEMETRY",
--- a/open-sse/services/antigravityHeaderScrub.ts
+++ b/open-sse/services/antigravityHeaderScrub.ts
@@ -30,6 +30,7 @@ const HEADERS_TO_REMOVE = [
  "x-stainless-helper-method",
  "http-referer",
  "referer",
+  "x-goog-api-client",
  // Browser / Chromium fingerprint (Electron clients, NOT Node.js)
  "sec-ch-ua",
  "sec-ch-ua-mobile",
--- a/open-sse/services/antigravityHeaders.ts
+++ b/open-sse/services/antigravityHeaders.ts
@@ -16,14 +16,13 @@ import {
 type AntigravityHeaderProfile = "loadCodeAssist" | "fetchAvailableModels" | "models";

 const ANTIGRAVITY_VERSION = ANTIGRAVITY_FALLBACK_VERSION;
-export const ANTIGRAVITY_LOAD_CODE_ASSIST_USER_AGENT = "google-api-nodejs-client/10.3.0";
-export const ANTIGRAVITY_LOAD_CODE_ASSIST_API_CLIENT =
-  "google-cloud-sdk vscode_cloudshelleditor/0.1";
+export const ANTIGRAVITY_CHROME_VERSION = "132.0.6834.160";
+export const ANTIGRAVITY_ELECTRON_VERSION = "39.2.3";
+export const ANTIGRAVITY_LOAD_CODE_ASSIST_USER_AGENT = `vscode/1.X.X (Antigravity/${ANTIGRAVITY_FALLBACK_VERSION})`;
+export const ANTIGRAVITY_LOAD_CODE_ASSIST_API_CLIENT = "";
 export const ANTIGRAVITY_CREDIT_PROBE_API_CLIENT = "google-genai-sdk/1.30.0 gl-node/v22.21.1";
 const LOAD_CODE_ASSIST_METADATA = Object.freeze({
-  ideType: "IDE_UNSPECIFIED",
-  platform: "PLATFORM_UNSPECIFIED",
-  pluginType: "GEMINI",
+  ideType: "ANTIGRAVITY",
 });

 function withOptionalBearerAuth(
@@ -37,20 +36,20 @@ function withOptionalBearerAuth(
 }

 /**
- * Antigravity User-Agent: "antigravity/VERSION darwin/arm64"
- *
- * Always claims darwin/arm64 regardless of actual server OS.
- * Real Antigravity is a macOS desktop tool — most users are on macOS.
- * Claiming linux/amd64 from a datacenter IP is MORE suspicious than
- * darwin/arm64. Matches CLIProxyAPI's proven production behavior.
+ * Antigravity desktop User-Agent:
+ * "Antigravity/VERSION (Macintosh; Intel Mac OS X 10_15_7) Chrome/132... Electron/39..."
 */
 export function antigravityUserAgent(): string {
-  return `antigravity/${getCachedAntigravityVersion()} darwin/arm64`;
+  return `Antigravity/${getCachedAntigravityVersion()} (Macintosh; Intel Mac OS X 10_15_7) Chrome/${ANTIGRAVITY_CHROME_VERSION} Electron/${ANTIGRAVITY_ELECTRON_VERSION}`;
 }

 export async function resolveAntigravityUserAgent(): Promise<string> {
  const version = await resolveAntigravityVersion();
-  return `antigravity/${version} darwin/arm64`;
+  return `Antigravity/${version} (Macintosh; Intel Mac OS X 10_15_7) Chrome/${ANTIGRAVITY_CHROME_VERSION} Electron/${ANTIGRAVITY_ELECTRON_VERSION}`;
+}
+
+export function antigravityNativeOAuthUserAgent(): string {
+  return `vscode/1.X.X (Antigravity/${getCachedAntigravityVersion()})`;
 }

 export function getAntigravityLoadCodeAssistMetadata(): Record<string, string> {
@@ -70,9 +69,7 @@ export function getAntigravityHeaders(
      return withOptionalBearerAuth(
        {
          "Content-Type": "application/json",
-          "User-Agent": ANTIGRAVITY_LOAD_CODE_ASSIST_USER_AGENT,
-          "X-Goog-Api-Client": ANTIGRAVITY_LOAD_CODE_ASSIST_API_CLIENT,
-          "Client-Metadata": getAntigravityLoadCodeAssistClientMetadata(),
+          "User-Agent": antigravityNativeOAuthUserAgent(),
        },
        accessToken
      );
--- a/open-sse/services/antigravityIdentity.ts
+++ b/open-sse/services/antigravityIdentity.ts
@@ -0,0 +1,102 @@
+import crypto from "node:crypto";
+
+type AntigravityCredentialsLike = {
+  accessToken?: string | null;
+  connectionId?: string | null;
+  email?: string | null;
+  projectId?: string | null;
+  providerSpecificData?: Record<string, unknown> | null;
+};
+
+const FNV_OFFSET_I64 = -3750763034362895579n;
+const FNV_PRIME_I64 = 1099511628211n;
+const PROCESS_SESSION_ID = crypto.randomUUID();
+
+function toNonEmptyString(value: unknown): string | null {
+  return typeof value === "string" && value.trim().length > 0 ? value.trim() : null;
+}
+
+function getProviderDataString(
+  credentials: AntigravityCredentialsLike | null | undefined,
+  key: string
+): string | null {
+  const data = credentials?.providerSpecificData;
+  return data && typeof data === "object" ? toNonEmptyString(data[key]) : null;
+}
+
+export function getAntigravityAccountKey(
+  credentials?: AntigravityCredentialsLike | null
+): string | null {
+  return (
+    toNonEmptyString(credentials?.email) ||
+    getProviderDataString(credentials, "email") ||
+    getProviderDataString(credentials, "accountId") ||
+    toNonEmptyString(credentials?.connectionId) ||
+    null
+  );
+}
+
+export function isAntigravityEnterpriseAccount(
+  credentials?: AntigravityCredentialsLike | null
+): boolean {
+  const email =
+    toNonEmptyString(credentials?.email) || getProviderDataString(credentials, "email") || "";
+  return !!email && !/@(?:gmail|googlemail)\.com$/i.test(email);
+}
+
+export function getAntigravityEnvelopeUserAgent(
+  credentials?: AntigravityCredentialsLike | null
+): "antigravity" | "jetski" {
+  return isAntigravityEnterpriseAccount(credentials) ? "jetski" : "antigravity";
+}
+
+export function generateAntigravityRequestId(): string {
+  return `agent/${Date.now()}/${crypto.randomBytes(4).toString("hex")}`;
+}
+
+export function generateAntigravitySessionId(): string {
+  const bytes = crypto.randomBytes(8);
+  const value = bytes.readBigUInt64BE() % 9_000_000_000_000_000_000n;
+  return `-${value.toString()}`;
+}
+
+export function deriveAntigravitySessionId(accountKey?: string | null): string | null {
+  const key = toNonEmptyString(accountKey);
+  if (!key) return null;
+
+  let hash = FNV_OFFSET_I64;
+  for (const byte of Buffer.from(key, "utf8")) {
+    hash = BigInt.asIntN(64, hash * FNV_PRIME_I64);
+    hash = BigInt.asIntN(64, hash ^ BigInt(byte));
+  }
+  return hash.toString();
+}
+
+export function getAntigravitySessionId(
+  credentials?: AntigravityCredentialsLike | null,
+  fallback?: unknown
+): string {
+  return (
+    deriveAntigravitySessionId(getAntigravityAccountKey(credentials)) ||
+    toNonEmptyString(fallback) ||
+    generateAntigravitySessionId()
+  );
+}
+
+export function deriveAntigravityMachineId(
+  credentials?: AntigravityCredentialsLike | null
+): string {
+  const key = getAntigravityAccountKey(credentials) || PROCESS_SESSION_ID;
+  const hex = crypto.createHash("sha256").update(`antigravity:${key}`).digest("hex");
+  return [
+    hex.slice(0, 8),
+    hex.slice(8, 12),
+    hex.slice(12, 16),
+    hex.slice(16, 20),
+    hex.slice(20, 32),
+  ].join("-");
+}
+
+export function getAntigravityVscodeSessionId(): string {
+  return PROCESS_SESSION_ID;
+}
--- a/open-sse/services/antigravityVersion.ts
+++ b/open-sse/services/antigravityVersion.ts
@@ -5,7 +5,7 @@ const ANTIGRAVITY_GITHUB_RELEASE_URL =

 export const ANTIGRAVITY_VERSION_CACHE_TTL_MS = 6 * 60 * 60 * 1000;
 export const ANTIGRAVITY_VERSION_FETCH_TIMEOUT_MS = 5_000;
-export const ANTIGRAVITY_FALLBACK_VERSION = "1.23.2";
+export const ANTIGRAVITY_FALLBACK_VERSION = "4.1.33";

 type VersionCache = {
  fetchedAt: number;
@@ -24,6 +24,25 @@ function normalizeVersion(value: unknown): string | null {
  return match ? match[1] : null;
 }

+function compareSemver(a: string, b: string): number {
+  const aParts = a.split(".").map((part) => Number.parseInt(part, 10) || 0);
+  const bParts = b.split(".").map((part) => Number.parseInt(part, 10) || 0);
+  for (let i = 0; i < 3; i += 1) {
+    if (aParts[i] !== bParts[i]) return aParts[i] - bParts[i];
+  }
+  return 0;
+}
+
+function pickNewestVersion(...versions: Array<string | null | undefined>): string {
+  return versions
+    .map((version) => normalizeVersion(version))
+    .filter((version): version is string => !!version)
+    .reduce(
+      (best, version) => (compareSemver(version, best) > 0 ? version : best),
+      ANTIGRAVITY_FALLBACK_VERSION
+    );
+}
+
 async function fetchJsonWithTimeout(fetchImpl: FetchLike, url: string): Promise<unknown> {
  const controller = new AbortController();
  const timeoutId = setTimeout(() => controller.abort(), ANTIGRAVITY_VERSION_FETCH_TIMEOUT_MS);
@@ -105,7 +124,9 @@ export async function resolveAntigravityVersion(fetchImpl: FetchLike = fetch): P

  inFlightRequest = (async () => {
    const resolved = await fetchLatestAntigravityVersion(fetchImpl);
-    const version = resolved || versionCache?.version || ANTIGRAVITY_FALLBACK_VERSION;
+    const version = resolved
+      ? pickNewestVersion(resolved, ANTIGRAVITY_FALLBACK_VERSION)
+      : pickNewestVersion(versionCache?.version, ANTIGRAVITY_FALLBACK_VERSION);

    if (resolved) {
      versionCache = {
--- a/open-sse/services/usage.ts
+++ b/open-sse/services/usage.ts
@@ -2,7 +2,6 @@
 * Usage Fetcher - Get usage data from provider APIs
 */

-import crypto from "node:crypto";
 import { PROVIDERS } from "../config/constants.ts";
 import {
  getAntigravityFetchAvailableModelsUrls,
@@ -19,7 +18,6 @@ import { safePercentage } from "@/shared/utils/formatting";
 import { fetchBailianQuota, type BailianTripleWindowQuota } from "./bailianQuotaFetcher.ts";
 import {
  antigravityUserAgent,
-  getAntigravityCreditProbeApiClientHeader,
  getAntigravityHeaders,
  getAntigravityLoadCodeAssistMetadata,
 } from "./antigravityHeaders.ts";
@@ -28,11 +26,18 @@ import {
  updateAntigravityRemainingCredits,
 } from "../executors/antigravity.ts";
 import { getCreditsMode } from "./antigravityCredits.ts";
+import {
+  deriveAntigravityMachineId,
+  generateAntigravityRequestId,
+  getAntigravitySessionId,
+  getAntigravityVscodeSessionId,
+} from "./antigravityIdentity.ts";
+import { getCachedAntigravityVersion } from "./antigravityVersion.ts";

 // Antigravity API config (credentials from PROVIDERS via credential loader)
 const ANTIGRAVITY_CONFIG = {
  quotaApiUrls: getAntigravityFetchAvailableModelsUrls(),
-  loadProjectApiUrl: "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
+  loadProjectApiUrl: "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:loadCodeAssist",
  tokenUrl: "https://oauth2.googleapis.com/token",
  get clientId() {
    return PROVIDERS.antigravity.clientId;
@@ -1493,13 +1498,13 @@ async function probeAntigravityCreditBalanceUncached(
    for (const baseUrl of ANTIGRAVITY_BASE_URLS) {
      const url = `${baseUrl}/v1internal:streamGenerateContent?alt=sse`;

-      const sessionId = `-${crypto.randomUUID()}`;
+      const sessionId = getAntigravitySessionId({ connectionId: accountId, projectId });
      const body = {
        project: projectId,
        model: "gemini-2-flash",
        userAgent: "antigravity",
        requestType: "agent",
-        requestId: `credits-probe-${Date.now()}`,
+        requestId: generateAntigravityRequestId(),
        enabledCreditTypes: ["GOOGLE_ONE_AI"],
        request: {
          model: "gemini-2-flash",
@@ -1513,7 +1518,11 @@ async function probeAntigravityCreditBalanceUncached(
        "Content-Type": "application/json",
        Authorization: `Bearer ${accessToken}`,
        "User-Agent": antigravityUserAgent(),
-        "X-Goog-Api-Client": getAntigravityCreditProbeApiClientHeader(),
+        "x-client-name": "antigravity",
+        "x-client-version": getCachedAntigravityVersion(),
+        "x-machine-id": deriveAntigravityMachineId({ connectionId: accountId, projectId }),
+        "x-vscode-sessionid": getAntigravityVscodeSessionId(),
+        "x-goog-user-project": projectId,
        Accept: "text/event-stream",
      };

--- a/open-sse/translator/request/openai-to-claude.ts
+++ b/open-sse/translator/request/openai-to-claude.ts
@@ -543,9 +543,27 @@ function tryParseJSON(str) {
  }
 }

+function stripCacheControl(value: unknown): unknown {
+  if (Array.isArray(value)) {
+    return value.map((item) => stripCacheControl(item));
+  }
+  if (!value || typeof value !== "object") {
+    return value;
+  }
+
+  const cleaned: Record<string, unknown> = {};
+  for (const [key, child] of Object.entries(value as Record<string, unknown>)) {
+    if (key === "cache_control") continue;
+    cleaned[key] = stripCacheControl(child);
+  }
+  return cleaned;
+}
+
 // OpenAI -> Claude format for Antigravity (without system prompt modifications)
 function openaiToClaudeRequestForAntigravity(model, body, stream) {
-  const result = openaiToClaudeRequest(model, body, stream);
+  const result = stripCacheControl(openaiToClaudeRequest(model, body, stream)) as ReturnType<
+    typeof openaiToClaudeRequest
+  >;

  // Strip prefix from tool names for Antigravity (doesn't use Claude OAuth)
  if (result.tools && Array.isArray(result.tools)) {
--- a/open-sse/translator/request/openai-to-gemini.ts
+++ b/open-sse/translator/request/openai-to-gemini.ts
@@ -4,6 +4,11 @@ import { DEFAULT_THINKING_GEMINI_SIGNATURE } from "../../config/defaultThinkingS
 import { ANTIGRAVITY_DEFAULT_SYSTEM } from "../../config/constants.ts";
 import { resolveGeminiThoughtSignature } from "../../services/geminiThoughtSignatureStore.ts";
 import { openaiToClaudeRequestForAntigravity } from "./openai-to-claude.ts";
+import {
+  generateAntigravityRequestId,
+  getAntigravityEnvelopeUserAgent,
+  getAntigravitySessionId,
+} from "../../services/antigravityIdentity.ts";
 import {
  capMaxOutputTokens,
  capThinkingBudget,
@@ -74,9 +79,10 @@ type CloudCodeEnvelope = {
  project: string;
  model: string;
  user_prompt_id?: string;
-  userAgent?: string;
+  userAgent?: "antigravity" | "jetski" | string;
  requestId?: string;
  requestType?: string;
+  enabledCreditTypes?: string[];
  request: {
    session_id?: string;
    sessionId?: string;
@@ -130,6 +136,28 @@ function extractClientThoughtSignature(toolCall: unknown): string | null {
  return typeof signature === "string" && signature.length > 0 ? signature : null;
 }

+function applyAntigravityGenerationDefaults(generationConfig: GeminiGenerationConfig) {
+  const config = { ...generationConfig };
+  if (config.topK === undefined) {
+    config.topK = 40;
+  }
+  if (config.topP === undefined) {
+    config.topP = 1.0;
+  }
+
+  const thinkingBudget = Number(config.thinkingConfig?.thinkingBudget);
+  const maxOutputTokens = Number(config.maxOutputTokens);
+  if (
+    Number.isFinite(thinkingBudget) &&
+    thinkingBudget > 0 &&
+    (!Number.isFinite(maxOutputTokens) || maxOutputTokens <= thinkingBudget)
+  ) {
+    config.maxOutputTokens = Math.floor(thinkingBudget) + 1;
+  }
+
+  return config;
+}
+
 // Core: Convert OpenAI request to Gemini format (base for all variants)
 function openaiToGeminiBase(model, body, stream, toolNameOptions: GeminiToolNameOptions = {}) {
  const result: GeminiRequest = {
@@ -421,17 +449,18 @@ function wrapInCloudCodeEnvelope(model, geminiCLI, credentials = null, isAntigra
  const envelope: CloudCodeEnvelope = isAntigravity
    ? {
        project: projectId,
-        model: cleanModel,
-        userAgent: "antigravity",
-        requestType: "agent",
-        requestId: `agent-${generateUUID()}`,
+        requestId: generateAntigravityRequestId(),
        request: {
-          sessionId: generateSessionId(),
+          sessionId: getAntigravitySessionId(credentials),
          contents: geminiCLI.contents,
          systemInstruction: geminiCLI.systemInstruction,
-          generationConfig: geminiCLI.generationConfig,
+          generationConfig: applyAntigravityGenerationDefaults(geminiCLI.generationConfig),
          tools: geminiCLI.tools,
        },
+        model: cleanModel,
+        userAgent: getAntigravityEnvelopeUserAgent(credentials),
+        requestType: "agent",
+        enabledCreditTypes: ["GOOGLE_ONE_AI"],
      }
    : {
        model: cleanModel,
@@ -512,16 +541,17 @@ function wrapInCloudCodeEnvelopeForClaude(

  const envelope: CloudCodeEnvelope = {
    project: projectId,
-    model: cleanModel,
-    userAgent: "antigravity",
-    requestId: `agent-${generateUUID()}`,
-    requestType: "agent",
+    requestId: generateAntigravityRequestId(),
    request: {
      ...claudeRequest,
      system: systemText,
      max_tokens: getAntigravityClaudeOutputTokens(sourceBody),
-      sessionId: generateSessionId(),
+      sessionId: getAntigravitySessionId(credentials),
    },
+    model: cleanModel,
+    userAgent: getAntigravityEnvelopeUserAgent(credentials),
+    requestType: "agent",
+    enabledCreditTypes: ["GOOGLE_ONE_AI"],
  };

  return envelope;
--- a/src/lib/oauth/constants/oauth.ts
+++ b/src/lib/oauth/constants/oauth.ts
@@ -63,7 +63,9 @@ export const GEMINI_CONFIG = {
    process.env.GEMINI_OAUTH_CLIENT_ID ||
    "681255809395-oo8ft2oprdrnp9e3aqf6av3hmdib135j.apps.googleusercontent.com",
  clientSecret:
-    process.env.GEMINI_CLI_OAUTH_CLIENT_SECRET || process.env.GEMINI_OAUTH_CLIENT_SECRET || "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",
+    process.env.GEMINI_CLI_OAUTH_CLIENT_SECRET ||
+    process.env.GEMINI_OAUTH_CLIENT_SECRET ||
+    "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",
  authorizeUrl: "https://accounts.google.com/o/oauth2/v2/auth",
  tokenUrl: "https://oauth2.googleapis.com/token",
  userInfoUrl: "https://www.googleapis.com/oauth2/v1/userinfo",
@@ -150,12 +152,13 @@ export const ANTIGRAVITY_CONFIG = {
    "https://www.googleapis.com/auth/experimentsandconfigs",
  ],
  // Antigravity specific
-  apiEndpoint: "https://cloudcode-pa.googleapis.com",
+  apiEndpoint: "https://daily-cloudcode-pa.sandbox.googleapis.com",
  apiVersion: "v1internal",
-  loadCodeAssistEndpoint: "https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist",
-  onboardUserEndpoint: "https://cloudcode-pa.googleapis.com/v1internal:onboardUser",
+  loadCodeAssistEndpoint:
+    "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:loadCodeAssist",
+  onboardUserEndpoint: "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:onboardUser",
  fetchAvailableModelsEndpoint:
-    "https://cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
+    "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:fetchAvailableModels",
  loadCodeAssistUserAgent: ANTIGRAVITY_LOAD_CODE_ASSIST_USER_AGENT,
  loadCodeAssistApiClient: ANTIGRAVITY_LOAD_CODE_ASSIST_API_CLIENT,
  loadCodeAssistClientMetadata: getAntigravityLoadCodeAssistClientMetadata(),
--- a/src/lib/oauth/providers/antigravity.ts
+++ b/src/lib/oauth/providers/antigravity.ts
@@ -1,5 +1,6 @@
 import { ANTIGRAVITY_CONFIG } from "../constants/oauth";
 import {
+  antigravityNativeOAuthUserAgent,
  getAntigravityHeaders,
  getAntigravityLoadCodeAssistMetadata,
 } from "@omniroute/open-sse/services/antigravityHeaders.ts";
@@ -36,6 +37,7 @@ export const antigravity = {
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
        Accept: "application/json",
+        "User-Agent": antigravityNativeOAuthUserAgent(),
      },
      body: new URLSearchParams(bodyParams),
    });
--- a/src/lib/oauth/services/antigravity.ts
+++ b/src/lib/oauth/services/antigravity.ts
@@ -2,6 +2,7 @@ import crypto from "crypto";
 import open from "open";
 import { ANTIGRAVITY_CONFIG } from "../constants/oauth";
 import {
+  antigravityNativeOAuthUserAgent,
  getAntigravityHeaders,
  getAntigravityLoadCodeAssistMetadata,
 } from "@omniroute/open-sse/services/antigravityHeaders.ts";
@@ -46,6 +47,7 @@ export class AntigravityService {
      headers: {
        "Content-Type": "application/x-www-form-urlencoded",
        Accept: "application/json",
+        "User-Agent": antigravityNativeOAuthUserAgent(),
      },
      body: new URLSearchParams({
        grant_type: "authorization_code",
--- a/src/lib/usage/fetcher.ts
+++ b/src/lib/usage/fetcher.ts
@@ -10,7 +10,6 @@ import {
 import {
  getAntigravityHeaders,
  antigravityUserAgent,
-  getAntigravityCreditProbeApiClientHeader,
 } from "@omniroute/open-sse/services/antigravityHeaders.ts";
 import {
  getAntigravityFetchAvailableModelsUrls,
@@ -21,6 +20,13 @@ import {
  updateAntigravityRemainingCredits,
 } from "@omniroute/open-sse/executors/antigravity.ts";
 import { getCreditsMode } from "@omniroute/open-sse/services/antigravityCredits.ts";
+import {
+  deriveAntigravityMachineId,
+  generateAntigravityRequestId,
+  getAntigravitySessionId,
+  getAntigravityVscodeSessionId,
+} from "@omniroute/open-sse/services/antigravityIdentity.ts";
+import { getCachedAntigravityVersion } from "@omniroute/open-sse/services/antigravityVersion.ts";

 /**
 * Get usage data for a provider connection
@@ -189,12 +195,13 @@ async function probeAntigravityCreditBalance(
      model: "gemini-2-flash",
      userAgent: "antigravity",
      requestType: "agent",
-      requestId: `credits-probe-${Date.now()}`,
+      requestId: generateAntigravityRequestId(),
      enabledCreditTypes: ["GOOGLE_ONE_AI"],
      request: {
        model: "gemini-2-flash",
        contents: [{ role: "user", parts: [{ text: "hi" }] }],
        generationConfig: { maxOutputTokens: 1 },
+        sessionId: getAntigravitySessionId({ connectionId: accountId, projectId }),
      },
    };

@@ -202,7 +209,11 @@ async function probeAntigravityCreditBalance(
      "Content-Type": "application/json",
      Authorization: `Bearer ${accessToken}`,
      "User-Agent": antigravityUserAgent(),
-      "X-Goog-Api-Client": getAntigravityCreditProbeApiClientHeader(),
+      "x-client-name": "antigravity",
+      "x-client-version": getCachedAntigravityVersion(),
+      "x-machine-id": deriveAntigravityMachineId({ connectionId: accountId, projectId }),
+      "x-vscode-sessionid": getAntigravityVscodeSessionId(),
+      "x-goog-user-project": projectId,
      Accept: "text/event-stream",
    };

--- a/src/mitm/server.cjs
+++ b/src/mitm/server.cjs
@@ -13,7 +13,11 @@ function getDataDir() {
 }

 // Configuration
-const TARGET_HOST = "daily-cloudcode-pa.googleapis.com";
+const TARGET_HOSTS = new Set([
+  "daily-cloudcode-pa.sandbox.googleapis.com",
+  "daily-cloudcode-pa.googleapis.com",
+  "cloudcode-pa.googleapis.com",
+]);
 const parsedLocalPort = Number.parseInt(process.env.MITM_LOCAL_PORT || "443", 10);
 const LOCAL_PORT =
  Number.isInteger(parsedLocalPort) && parsedLocalPort > 0 && parsedLocalPort <= 65535
@@ -112,15 +116,23 @@ function saveResponseLog(url, data) {
 }

 // Resolve real IP of target host (bypass /etc/hosts)
-let cachedTargetIP = null;
-async function resolveTargetIP() {
-  if (cachedTargetIP) return cachedTargetIP;
+const cachedTargetIPs = new Map();
+function getTargetHost(req) {
+  const host = String(req.headers.host || "")
+    .split(":")[0]
+    .toLowerCase();
+  return TARGET_HOSTS.has(host) ? host : "daily-cloudcode-pa.sandbox.googleapis.com";
+}
+
+async function resolveTargetIP(targetHost) {
+  if (cachedTargetIPs.has(targetHost)) return cachedTargetIPs.get(targetHost);
  const resolver = new dns.Resolver();
  resolver.setServers(["8.8.8.8"]);
  const resolve4 = promisify(resolver.resolve4.bind(resolver));
-  const addresses = await resolve4(TARGET_HOST);
-  cachedTargetIP = addresses[0];
-  return cachedTargetIP;
+  const addresses = await resolve4(targetHost);
+  const targetIP = addresses[0];
+  cachedTargetIPs.set(targetHost, targetIP);
+  return targetIP;
 }

 function collectBodyRaw(req) {
@@ -193,7 +205,8 @@ function getMappedModel(model) {
 }

 async function passthrough(req, res, bodyBuffer) {
-  const targetIP = await resolveTargetIP();
+  const targetHost = getTargetHost(req);
+  const targetIP = await resolveTargetIP(targetHost);

  // TLS validation is enabled by default. Set MITM_DISABLE_TLS_VERIFY=1 only
  // in controlled local environments where the target uses a self-signed cert.
@@ -205,8 +218,8 @@ async function passthrough(req, res, bodyBuffer) {
      port: 443,
      path: req.url,
      method: req.method,
-      headers: { ...req.headers, host: TARGET_HOST },
-      servername: TARGET_HOST,
+      headers: { ...req.headers, host: targetHost },
+      servername: targetHost,
      rejectUnauthorized,
    },
    (forwardRes) => {
--- a/tests/unit/antigravity-version.test.ts
+++ b/tests/unit/antigravity-version.test.ts
@@ -21,7 +21,7 @@ test("resolveAntigravityVersion uses the official release feed and caches the re
  let calls = 0;
  const fetchMock = async () => {
    calls += 1;
-    return new Response(JSON.stringify([{ version: "1.22.2", execution_id: "4781536860569600" }]), {
+    return new Response(JSON.stringify([{ version: "4.2.0", execution_id: "4781536860569600" }]), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });
@@ -30,10 +30,10 @@ test("resolveAntigravityVersion uses the official release feed and caches the re
  const first = await resolveAntigravityVersion(fetchMock as typeof fetch);
  const second = await resolveAntigravityVersion(fetchMock as typeof fetch);

-  assert.equal(first, "1.22.2");
-  assert.equal(second, "1.22.2");
+  assert.equal(first, "4.2.0");
+  assert.equal(second, "4.2.0");
  assert.equal(calls, 1);
-  assert.equal(getCachedAntigravityVersion(), "1.22.2");
+  assert.equal(getCachedAntigravityVersion(), "4.2.0");
 });

 test("resolveAntigravityVersion refreshes the cache after the TTL elapses", async () => {
@@ -41,22 +41,22 @@ test("resolveAntigravityVersion refreshes the cache after the TTL elapses", asyn
  Date.now = () => now;

  const firstFetch = async () =>
-    new Response(JSON.stringify([{ version: "1.22.2" }]), {
+    new Response(JSON.stringify([{ version: "4.2.0" }]), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });
  const secondFetch = async () =>
-    new Response(JSON.stringify([{ version: "1.24.0" }]), {
+    new Response(JSON.stringify([{ version: "4.3.0" }]), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });

-  assert.equal(await resolveAntigravityVersion(firstFetch as typeof fetch), "1.22.2");
+  assert.equal(await resolveAntigravityVersion(firstFetch as typeof fetch), "4.2.0");

  now += ANTIGRAVITY_VERSION_CACHE_TTL_MS + 1;

-  assert.equal(await resolveAntigravityVersion(secondFetch as typeof fetch), "1.24.0");
-  assert.equal(getCachedAntigravityVersion(), "1.24.0");
+  assert.equal(await resolveAntigravityVersion(secondFetch as typeof fetch), "4.3.0");
+  assert.equal(getCachedAntigravityVersion(), "4.3.0");
 });

 test("resolveAntigravityVersion falls back to the last known good version or bundled fallback", async () => {
@@ -69,8 +69,8 @@ test("resolveAntigravityVersion falls back to the last known good version or bun
    ANTIGRAVITY_FALLBACK_VERSION
  );

-  seedAntigravityVersionCache("1.23.1", 0);
-  assert.equal(await resolveAntigravityVersion(failingFetch as typeof fetch), "1.23.1");
+  seedAntigravityVersionCache("4.2.1", 0);
+  assert.equal(await resolveAntigravityVersion(failingFetch as typeof fetch), "4.2.1");
 });

 test("resolveAntigravityVersion parses GitHub-style tag_name payloads with or without a v prefix", async () => {
@@ -84,11 +84,11 @@ test("resolveAntigravityVersion parses GitHub-style tag_name payloads with or wi
      });
    }

-    return new Response(JSON.stringify({ tag_name: "v1.24.3" }), {
+    return new Response(JSON.stringify({ tag_name: "v4.2.3" }), {
      status: 200,
      headers: { "Content-Type": "application/json" },
    });
  };

-  assert.equal(await resolveAntigravityVersion(fetchMock as typeof fetch), "1.24.3");
+  assert.equal(await resolveAntigravityVersion(fetchMock as typeof fetch), "4.2.3");
 });
--- a/tests/unit/executor-antigravity.test.ts
+++ b/tests/unit/executor-antigravity.test.ts
@@ -50,6 +50,7 @@ test("AntigravityExecutor.buildHeaders includes native headers without OmniRoute

  assert.equal(headers.Authorization, "Bearer ag-token");
  assert.equal(headers.Accept, "text/event-stream");
+  assert.match(headers["User-Agent"], /^Antigravity\/4\.1\.33 /);
  assert.equal(headers["X-OmniRoute-Source"], undefined);
 });

@@ -98,14 +99,19 @@ test("AntigravityExecutor.transformRequest normalizes model, project and content
  assert.equal(result.model, "gemini-3.1-pro-low");
  assert.deepEqual(Object.keys(result), [
    "project",
+    "requestId",
+    "request",
    "model",
    "userAgent",
    "requestType",
-    "requestId",
-    "request",
+    "enabledCreditTypes",
  ]);
  assert.equal(result.userAgent, "antigravity");
+  assert.match(result.requestId, /^agent\/\d+\/[0-9a-f]{8}$/);
+  assert.deepEqual(result.enabledCreditTypes, ["GOOGLE_ONE_AI"]);
  assert.ok(result.request.sessionId);
+  assert.equal(result.request.generationConfig.topK, 40);
+  assert.equal(result.request.generationConfig.topP, 1.0);
  assert.deepEqual(result.request.toolConfig, {
    functionCallingConfig: { mode: "VALIDATED" },
  });
@@ -466,15 +472,21 @@ test("AntigravityExecutor.execute applies CLI fingerprint when enabled", async (
    const headers = init?.headers as Record<string, string>;
    const parsedBody = JSON.parse(String(init?.body));

-    assert.equal(headers["User-Agent"], "antigravity/2026.04.17-test darwin/arm64");
+    assert.equal(
+      headers["User-Agent"],
+      "Antigravity/2026.04.17-test (Macintosh; Intel Mac OS X 10_15_7) Chrome/132.0.6834.160 Electron/39.2.3"
+    );
+    assert.equal(headers["x-client-name"], "antigravity");
+    assert.equal(headers["x-client-version"], "2026.04.17-test");
+    assert.equal(headers["x-goog-user-project"], "project-1");
    assert.deepEqual(Object.keys(parsedBody), [
      "project",
+      "requestId",
+      "request",
      "model",
      "userAgent",
      "requestType",
-      "requestId",
      "enabledCreditTypes",
-      "request",
    ]);

    return new Response(
@@ -530,6 +542,7 @@ test("AntigravityExecutor.transformRequest bypasses Gemini contents mapping for
  assert.equal(result.model, "claude-sonnet-4-6");
  assert.equal(result.requestType, "agent");
  assert.ok(result.request.sessionId);
+  assert.deepEqual(result.enabledCreditTypes, ["GOOGLE_ONE_AI"]);
  assert.deepEqual(result.request.messages, [
    { role: "user", content: [{ type: "text", text: "Hello" }] },
  ]);
--- a/tests/unit/oauth-providers-config.test.ts
+++ b/tests/unit/oauth-providers-config.test.ts
@@ -438,19 +438,10 @@ test("Gemini and Antigravity run mocked browser OAuth exchanges and post-exchang
    (_url, init = {}) => {
      assert.equal(init.method, "POST");
      assert.equal(init.headers.Authorization, "Bearer anti-access");
-      assert.equal(init.headers["User-Agent"], "google-api-nodejs-client/10.3.0");
-      assert.equal(
-        init.headers["X-Goog-Api-Client"],
-        "google-cloud-sdk vscode_cloudshelleditor/0.1"
-      );
-      assert.equal(
-        init.headers["Client-Metadata"],
-        JSON.stringify({
-          ideType: "IDE_UNSPECIFIED",
-          platform: "PLATFORM_UNSPECIFIED",
-          pluginType: "GEMINI",
-        })
-      );
+      assert.match(init.headers["User-Agent"], /^vscode\/1\.X\.X \(Antigravity\//);
+      assert.equal(init.headers["X-Goog-Api-Client"], undefined);
+      assert.equal(init.headers["Client-Metadata"], undefined);
+      assert.deepEqual(JSON.parse(String(init.body)).metadata, { ideType: "ANTIGRAVITY" });
      return jsonResponse({
        cloudaicompanionProject: { id: "anti-project" },
        allowedTiers: [{ id: "tier-default", isDefault: true }],
@@ -459,11 +450,9 @@ test("Gemini and Antigravity run mocked browser OAuth exchanges and post-exchang
    (_url, init = {}) => {
      assert.equal(init.method, "POST");
      assert.equal(init.headers.Authorization, "Bearer anti-access");
-      assert.equal(init.headers["User-Agent"], "google-api-nodejs-client/10.3.0");
-      assert.equal(
-        init.headers["X-Goog-Api-Client"],
-        "google-cloud-sdk vscode_cloudshelleditor/0.1"
-      );
+      assert.match(init.headers["User-Agent"], /^vscode\/1\.X\.X \(Antigravity\//);
+      assert.equal(init.headers["X-Goog-Api-Client"], undefined);
+      assert.deepEqual(JSON.parse(String(init.body)).metadata, { ideType: "ANTIGRAVITY" });
      return jsonResponse({
        done: true,
        response: { cloudaicompanionProject: { id: "anti-project-final" } },
--- a/tests/unit/provider-models-route.test.ts
+++ b/tests/unit/provider-models-route.test.ts
@@ -651,7 +651,7 @@ test("provider models route retries Antigravity discovery endpoints before retur

    assert.equal(init.method, "POST");
    assert.equal(init.headers.Authorization, "Bearer ag-access");
-    assert.match(init.headers["User-Agent"], /^antigravity\//);
+    assert.match(init.headers["User-Agent"], /^Antigravity\//);
    return Response.json({
      models: [{ id: "gemini-3-flash", displayName: "Gemini 3 Flash" }],
    });
@@ -664,7 +664,7 @@ test("provider models route retries Antigravity discovery endpoints before retur
  assert.equal(response.status, 200);
  assert.equal(body.source, "api");
  assert.deepEqual(discoveryUrls, [
-    "https://cloudcode-pa.googleapis.com/v1internal:models",
+    "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:models",
    "https://daily-cloudcode-pa.googleapis.com/v1internal:models",
  ]);
  assert.deepEqual(body.models, [{ id: "gemini-3-flash-preview", name: "Gemini 3 Flash" }]);
@@ -691,9 +691,9 @@ test("provider models route falls back through all Antigravity discovery endpoin
  assert.equal(body.source, "local_catalog");
  assert.match(body.warning, /local catalog/i);
  assert.deepEqual(discoveryUrls, [
-    "https://cloudcode-pa.googleapis.com/v1internal:models",
-    "https://daily-cloudcode-pa.googleapis.com/v1internal:models",
    "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:models",
+    "https://daily-cloudcode-pa.googleapis.com/v1internal:models",
+    "https://cloudcode-pa.googleapis.com/v1internal:models",
  ]);
  assert.ok(body.models.some((model) => model.id === "gemini-3-pro-preview"));
 });
--- a/tests/unit/t20-t22-provider-headers.test.ts
+++ b/tests/unit/t20-t22-provider-headers.test.ts
@@ -9,9 +9,7 @@ const { geminiCliUserAgent, GEMINI_CLI_VERSION } =
 test("T20: antigravity config has updated User-Agent and sandbox fallback URL", () => {
  const antigravity = REGISTRY.antigravity;
  assert.ok(Array.isArray(antigravity.baseUrls));
-  assert.ok(
-    antigravity.baseUrls.some((u) => u === "https://daily-cloudcode-pa.sandbox.googleapis.com")
-  );
+  assert.equal(antigravity.baseUrls[0], "https://daily-cloudcode-pa.sandbox.googleapis.com");
  assert.equal(antigravity.headers["User-Agent"], antigravityUserAgent());
 });

--- a/tests/unit/translator-openai-to-gemini.test.ts
+++ b/tests/unit/translator-openai-to-gemini.test.ts
@@ -597,16 +597,20 @@ test("OpenAI -> Antigravity wraps Gemini requests in a Cloud Code envelope", ()
  assert.equal(result.project, "proj-1");
  assert.deepEqual(Object.keys(result), [
    "project",
+    "requestId",
+    "request",
    "model",
    "userAgent",
    "requestType",
-    "requestId",
-    "request",
+    "enabledCreditTypes",
  ]);
  assert.equal(result.userAgent, "antigravity");
  assert.equal(result.requestType, "agent");
-  assert.match(result.requestId, /^agent-/);
-  assert.match(result.request.sessionId, /^-\d+$/);
+  assert.match(result.requestId, /^agent\/\d+\/[0-9a-f]{8}$/);
+  assert.match(result.request.sessionId, /^-?\d+$/);
+  assert.deepEqual(result.enabledCreditTypes, ["GOOGLE_ONE_AI"]);
+  assert.equal(result.request.generationConfig.topK, 40);
+  assert.equal(result.request.generationConfig.topP, 1.0);
  assert.equal(
    (result as any).request?.systemInstruction.parts[0].text,
    ANTIGRAVITY_DEFAULT_SYSTEM
@@ -659,6 +663,8 @@ test("OpenAI -> Antigravity uses the Claude bridge for Claude-family models", ()

  assert.equal(result.project, "proj-claude");
  assert.equal(result.userAgent, "antigravity");
+  assert.match(result.requestId, /^agent\/\d+\/[0-9a-f]{8}$/);
+  assert.deepEqual((result as any).enabledCreditTypes, ["GOOGLE_ONE_AI"]);
  assert.ok((result as any).request?.system.includes(ANTIGRAVITY_DEFAULT_SYSTEM));
  assert.ok((result as any).request?.system.includes("Project rules"));
  assert.equal((result as any).request?.max_tokens, 16384);
--- a/tests/unit/usage-service-hardening.test.ts
+++ b/tests/unit/usage-service-hardening.test.ts
@@ -323,19 +323,13 @@ test("usage service covers Antigravity quota parsing, exclusions and forbidden a
  assert.equal(usage.quotas["gemini-3.1-pro-high"].total, 0);
  assert.equal(usage.quotas["gemini-3.1-pro-high"].remainingPercentage, 100);
  const loadCodeAssistCall = calls.find((call) => call.url.includes("loadCodeAssist"));
-  assert.equal(loadCodeAssistCall?.init.headers["User-Agent"], "google-api-nodejs-client/10.3.0");
-  assert.equal(
-    loadCodeAssistCall?.init.headers["X-Goog-Api-Client"],
-    "google-cloud-sdk vscode_cloudshelleditor/0.1"
-  );
-  assert.equal(
-    loadCodeAssistCall?.init.headers["Client-Metadata"],
-    JSON.stringify({
-      ideType: "IDE_UNSPECIFIED",
-      platform: "PLATFORM_UNSPECIFIED",
-      pluginType: "GEMINI",
-    })
-  );
+  assert.match(loadCodeAssistCall?.url, /daily-cloudcode-pa\.sandbox\.googleapis\.com/);
+  assert.match(loadCodeAssistCall?.init.headers["User-Agent"], /^vscode\/1\.X\.X \(Antigravity\//);
+  assert.equal(loadCodeAssistCall?.init.headers["X-Goog-Api-Client"], undefined);
+  assert.equal(loadCodeAssistCall?.init.headers["Client-Metadata"], undefined);
+  assert.deepEqual(JSON.parse(loadCodeAssistCall?.init.body).metadata, {
+    ideType: "ANTIGRAVITY",
+  });

  globalThis.fetch = async (url) => {
    if (String(url).includes("loadCodeAssist")) {
@@ -369,7 +363,7 @@ test("usage service retries Antigravity fetchAvailableModels across the shared f

    try {
      const parsedUrl = new URL(String(url));
-      if (parsedUrl.hostname === "cloudcode-pa.googleapis.com") {
+      if (parsedUrl.hostname === "daily-cloudcode-pa.sandbox.googleapis.com") {
        return new Response("bad gateway", { status: 502 });
      }
      if (parsedUrl.hostname === "daily-cloudcode-pa.googleapis.com") {
@@ -403,12 +397,12 @@ test("usage service retries Antigravity fetchAvailableModels across the shared f
  assert.deepEqual(
    quotaCalls.map((call) => call.url),
    [
-      "https://cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
-      "https://daily-cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
      "https://daily-cloudcode-pa.sandbox.googleapis.com/v1internal:fetchAvailableModels",
+      "https://daily-cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
+      "https://cloudcode-pa.googleapis.com/v1internal:fetchAvailableModels",
    ]
  );
-  assert.match(quotaCalls[2].init.headers["User-Agent"], /^antigravity\//);
+  assert.match(quotaCalls[2].init.headers["User-Agent"], /^Antigravity\//);
  assert.equal(usage.plan, "Business");
  assert.equal(usage.quotas["claude-sonnet-4-6"].used, 500);
 });