feat: add Gemini 3.6 Flash support

Author: ualtinok

README.md

@@ -1,7 +1,7 @@
 # Antigravity Auth
 
 Google Antigravity OAuth for coding agents. Authenticate with your Google
-account and access **Gemini 3**, **Claude 4.6**, and **GPT-OSS 120B** models through
+account and access **Gemini 3.6**, **Claude 4.6**, and **GPT-OSS 120B** models through
 Antigravity's endpoints.
 
 This is a monorepo publishing three packages:

packages/core/src/agy-request-metadata.test.ts

@@ -20,9 +20,9 @@ type ModelMetadataFixture = {
   }>
 }
 
-const MODEL_METADATA_FIXTURE = JSON.parse(
-  readFileSync(new URL("../../../test-fixtures/agy-cli-1.1.3-model-metadata.json", import.meta.url), "utf8"),
-) as ModelMetadataFixture
+const MODEL_METADATA_FIXTURES = ["1.1.3", "1.1.5"].map((version) => JSON.parse(
+  readFileSync(new URL(`../../../test-fixtures/agy-cli-${version}-model-metadata.json`, import.meta.url), "utf8"),
+) as ModelMetadataFixture)
 
 describe("agy request metadata", () => {
   it("matches the captured signed FNV-1a session ID for an empty workspace URI", () => {
@@ -54,7 +54,7 @@ describe("agy request metadata", () => {
     })
   })
 
-  it("orders request fields like captured agy 1.1.3 payloads", () => {
+  it("orders request fields like captured agy 1.1.5 payloads", () => {
     const payload: Record<string, unknown> = {
       generationConfig: {},
       sessionId: "session",
@@ -132,9 +132,11 @@ describe("agy request metadata", () => {
     })
   })
 
-  it("matches every captured agy 1.1.3 model enum fixture", () => {
-    for (const [model, expected] of Object.entries(MODEL_METADATA_FIXTURE.models)) {
-      expect(getAgyModelEnum(model), model).toBe(expected.modelEnum)
+  it("matches every captured agy model enum fixture", () => {
+    for (const fixture of MODEL_METADATA_FIXTURES) {
+      for (const [model, expected] of Object.entries(fixture.models)) {
+        expect(getAgyModelEnum(model), model).toBe(expected.modelEnum)
+      }
     }
   })
 

packages/core/src/agy-request-metadata.ts

@@ -20,6 +20,9 @@ const AGY_MODEL_ENUM_BY_WIRE_MODEL: Readonly<Record<string, string>> = {
   "gemini-3.5-flash-extra-low": "MODEL_PLACEHOLDER_M187",
   "gemini-3.5-flash-low": "MODEL_PLACEHOLDER_M20",
   "gemini-3-flash-agent": "MODEL_PLACEHOLDER_M84",
+  "gemini-3.6-flash-low": "MODEL_PLACEHOLDER_M266",
+  "gemini-3.6-flash-medium": "MODEL_PLACEHOLDER_M265",
+  "gemini-3.6-flash-high": "MODEL_PLACEHOLDER_M264",
   "gemini-3.1-pro-low": "MODEL_PLACEHOLDER_M36",
   "gemini-pro-agent": "MODEL_PLACEHOLDER_M16",
   "claude-sonnet-4-6": "MODEL_PLACEHOLDER_M35",

packages/core/src/agy-transport.test.ts

@@ -22,8 +22,8 @@ type AgyWireFixture = {
   requestKeys: string[]
 }
 
-const AGY_1_1_3_WIRE_FIXTURE = JSON.parse(
-  readFileSync(new URL("../../../test-fixtures/agy-cli-1.1.3-stream-request.json", import.meta.url), "utf8"),
+const AGY_1_1_5_WIRE_FIXTURE = JSON.parse(
+  readFileSync(new URL("../../../test-fixtures/agy-cli-1.1.5-stream-request.json", import.meta.url), "utf8"),
 ) as AgyWireFixture
 
 const savedProxyEnv = {
@@ -65,13 +65,13 @@ describe("agy transport", () => {
     expect(DEFAULT_AGY_IDLE_TIMEOUT_MS).toBe(180_000)
   })
 
-  it("serializes the captured agy CLI 1.1.3 stream header contract", () => {
-    const pairs = buildAgyCliHeaderPairs(AGY_1_1_3_WIRE_FIXTURE.capture.endpoint, {
+  it("serializes the captured agy CLI 1.1.5 stream header contract", () => {
+    const pairs = buildAgyCliHeaderPairs(AGY_1_1_5_WIRE_FIXTURE.capture.endpoint, {
       method: "POST",
       headers: {
         Authorization: "Bearer token",
         "Content-Type": "application/json",
-        "User-Agent": "antigravity/cli/1.1.3 (aidev_client; os_type=darwin; arch=arm64; auth_method=consumer)",
+        "User-Agent": "antigravity/cli/1.1.5 (aidev_client; os_type=darwin; arch=arm64; auth_method=consumer)",
         "Accept-Encoding": "gzip",
       },
       body: JSON.stringify({ request: { contents: [] } }),
@@ -80,11 +80,11 @@ describe("agy transport", () => {
       name === "Authorization" ? "<redacted>" : value,
     ])
 
-    expect(AGY_1_1_3_WIRE_FIXTURE.capture).toMatchObject({
-      version: "1.1.3",
+    expect(AGY_1_1_5_WIRE_FIXTURE.capture).toMatchObject({
+      version: "1.1.5",
       httpVersion: "HTTP/1.1",
     })
-    expect(pairs).toEqual(AGY_1_1_3_WIRE_FIXTURE.headers)
+    expect(pairs).toEqual(AGY_1_1_5_WIRE_FIXTURE.headers)
   })
 
   it("rejects immediately when the signal is already aborted", async () => {
@@ -117,7 +117,7 @@ describe("agy transport", () => {
       await expect(fetchWithAgyCliTransport("https://example.com/v1internal:streamGenerateContent", {
         method: "POST",
         headers: {
-          "User-Agent": "antigravity/cli/1.1.3 (aidev_client; os_type=darwin; arch=arm64; auth_method=consumer)",
+          "User-Agent": "antigravity/cli/1.1.5 (aidev_client; os_type=darwin; arch=arm64; auth_method=consumer)",
         },
         body: JSON.stringify({ x: 1 }),
       }, {

packages/core/src/constants.ts

@@ -29,7 +29,7 @@ export const ANTIGRAVITY_REDIRECT_URI = "http://localhost:51121/oauth-callback";
 
 /**
  * Root endpoints for the Antigravity API (in fallback order).
- * Live agy CLI 1.1.3 traffic uses daily-cloudcode-pa.googleapis.com.
+ * Live agy CLI 1.1.5 traffic uses daily-cloudcode-pa.googleapis.com.
  */
 export const ANTIGRAVITY_ENDPOINT_DAILY = "https://daily-cloudcode-pa.googleapis.com";
 export const ANTIGRAVITY_ENDPOINT_AUTOPUSH = "https://autopush-cloudcode-pa.sandbox.googleapis.com";

packages/core/src/fingerprint.ts

@@ -1,15 +1,15 @@
 /**
  * Device Fingerprint Generator for Rate Limit Mitigation
  *
- * Uses the agy CLI 1.1.3 content-request identity captured with mitmproxy:
+ * Uses the agy CLI 1.1.5 content-request identity captured with mitmproxy:
  * an Antigravity CLI User-Agent with explicit client, OS, architecture, and auth metadata.
  * The stored deviceId/sessionToken fields are
  * retained for account history, but content requests only send User-Agent.
  */
 
 import * as crypto from "node:crypto";
 
-export const AGY_CLI_VERSION = "1.1.3";
+export const AGY_CLI_VERSION = "1.1.5";
 const ANTIGRAVITY_API_CLIENT = "antigravity-cli";
 
 export interface ClientMetadata {

packages/core/src/model-registry.test.ts

@@ -3,6 +3,7 @@ import { describe, expect, it } from "vitest"
 import {
   getGemini35FlashAntigravityModel,
   getGemini35FlashGeminiCliFallbackModel,
+  getGemini36FlashAntigravityModel,
   getPublicModelDefinitions,
   getResolverAliasMap,
 } from "./model-registry.ts"
@@ -31,6 +32,7 @@ describe("model registry", () => {
       "antigravity-gemini-3.1-flash-image",
       "antigravity-gemini-3.1-pro",
       "antigravity-gemini-3.5-flash",
+      "antigravity-gemini-3.6-flash",
       "antigravity-gpt-oss-120b-medium",
     ])
 
@@ -49,10 +51,18 @@ describe("model registry", () => {
     expect(getGemini35FlashGeminiCliFallbackModel()).toBe("gemini-3-flash-preview")
   })
 
+  it("preserves live Gemini 3.6 Flash route mappings", () => {
+    expect(getGemini36FlashAntigravityModel()).toBe("gemini-3.6-flash-medium")
+    expect(getGemini36FlashAntigravityModel("high")).toBe("gemini-3.6-flash-high")
+    expect(getGemini36FlashAntigravityModel("medium")).toBe("gemini-3.6-flash-medium")
+    expect(getGemini36FlashAntigravityModel("low")).toBe("gemini-3.6-flash-low")
+  })
+
   it("keeps resolver aliases for supported agy CLI variants", () => {
     const aliases = getResolverAliasMap()
 
     expect(aliases["gemini-3.5-flash-medium"]).toBe("gemini-3.5-flash")
+    expect(aliases["gemini-3.6-flash-medium"]).toBe("gemini-3.6-flash")
     expect(aliases["gemini-claude-opus-4-6-thinking-medium"]).toBe("claude-opus-4-6-thinking")
     expect(aliases["gemini-claude-sonnet-4-6-thinking-high"]).toBe("claude-sonnet-4-6")
     expect(aliases["gpt-oss-120b"]).toBe("gpt-oss-120b-medium")

packages/core/src/model-registry.ts

@@ -54,11 +54,13 @@ interface OpencodeModelDefinitionInput {
   variants?: Record<string, ModelVariant>
 }
 
-interface Gemini35FlashRouteMetadata {
-  antigravity: {
-    defaultModel: string
-    byTier: Partial<Record<ThinkingTier, string>>
-  }
+interface AntigravityTieredRouteMetadata {
+  defaultModel: string
+  byTier: Partial<Record<ThinkingTier, string>>
+}
+
+interface GeminiFlashRouteMetadata {
+  antigravity: AntigravityTieredRouteMetadata
   geminiCliFallbackModel: string
 }
 
@@ -98,6 +100,16 @@ const ALL_MODEL_DEFINITIONS: OpencodeModelDefinitions = {
       high: { thinkingLevel: "high" },
     },
   }),
+  "antigravity-gemini-3.6-flash": defineModel("antigravity-gemini-3.6-flash", {
+    name: "Gemini 3.6 Flash (Antigravity)",
+    reasoning: true,
+    limit: { context: 1048576, output: 65536 },
+    modalities: DEFAULT_MODALITIES,
+    variants: {
+      low: { thinkingLevel: "low" },
+      high: { thinkingLevel: "high" },
+    },
+  }),
   "antigravity-gemini-3.5-flash": defineModel("antigravity-gemini-3.5-flash", {
     name: "Gemini 3.5 Flash (Antigravity)",
     reasoning: true,
@@ -208,6 +220,9 @@ const RESOLVER_ALIASES: Record<string, string> = {
   "gemini-3.5-flash-low": "gemini-3.5-flash",
   "gemini-3.5-flash-medium": "gemini-3.5-flash",
   "gemini-3.5-flash-high": "gemini-3.5-flash",
+  "gemini-3.6-flash-low": "gemini-3.6-flash",
+  "gemini-3.6-flash-medium": "gemini-3.6-flash",
+  "gemini-3.6-flash-high": "gemini-3.6-flash",
   "gemini-claude-opus-4-6-thinking-low": "claude-opus-4-6-thinking",
   "gemini-claude-opus-4-6-thinking-medium": "claude-opus-4-6-thinking",
   "gemini-claude-opus-4-6-thinking-high": "claude-opus-4-6-thinking",
@@ -222,7 +237,7 @@ const RESOLVER_ALIASES: Record<string, string> = {
   "gpt-oss-120b": "gpt-oss-120b-medium",
 }
 
-const GEMINI_35_FLASH_ROUTES: Gemini35FlashRouteMetadata = {
+const GEMINI_35_FLASH_ROUTES: GeminiFlashRouteMetadata = {
   antigravity: {
     defaultModel: "gemini-3-flash-agent",
     byTier: {
@@ -234,6 +249,15 @@ const GEMINI_35_FLASH_ROUTES: Gemini35FlashRouteMetadata = {
   geminiCliFallbackModel: "gemini-3-flash-preview",
 }
 
+const GEMINI_36_FLASH_ROUTES: AntigravityTieredRouteMetadata = {
+  defaultModel: "gemini-3.6-flash-medium",
+  byTier: {
+    low: "gemini-3.6-flash-low",
+    medium: "gemini-3.6-flash-medium",
+    high: "gemini-3.6-flash-high",
+  },
+}
+
 const QUOTA_GROUP_BY_MODEL_ID: Record<string, ModelQuotaGroup> = {
   "claude-opus-4-6-thinking": "claude",
   "claude-opus-4-6": "claude",
@@ -247,12 +271,17 @@ const QUOTA_GROUP_BY_MODEL_ID: Record<string, ModelQuotaGroup> = {
   "gemini-3-flash-agent": "gemini-flash",
   "gemini-3.5-flash-low": "gemini-flash",
   "gemini-3.5-flash-extra-low": "gemini-flash",
+  "gemini-3.6-flash-low": "gemini-flash",
+  "gemini-3.6-flash-medium": "gemini-flash",
+  "gemini-3.6-flash-high": "gemini-flash",
+  "gemini-3.6-flash-tiered": "gemini-flash",
   "gemini-3.1-flash-image": "gemini-flash",
   "gpt-oss-120b": "gpt-oss",
   "gpt-oss-120b-medium": "gpt-oss",
 }
 
 const ANTIGRAVITY_OPENCODE_MODEL_IDS = [
+  "antigravity-gemini-3.6-flash",
   "antigravity-gemini-3.5-flash",
   "antigravity-gemini-3.1-pro",
   "antigravity-claude-sonnet-4-6-thinking",
@@ -290,6 +319,13 @@ export function getGemini35FlashGeminiCliFallbackModel(): string {
   return GEMINI_35_FLASH_ROUTES.geminiCliFallbackModel
 }
 
+export function getGemini36FlashAntigravityModel(tier?: ThinkingTier): string {
+  if (!tier) {
+    return GEMINI_36_FLASH_ROUTES.defaultModel
+  }
+  return GEMINI_36_FLASH_ROUTES.byTier[tier] ?? GEMINI_36_FLASH_ROUTES.defaultModel
+}
+
 export function getQuotaGroupForModel(modelId: string): ModelQuotaGroup | undefined {
   return QUOTA_GROUP_BY_MODEL_ID[modelId.toLowerCase()]
 }

packages/core/src/project.test.ts

@@ -43,7 +43,7 @@ describe("project bootstrap", () => {
 
     expect(headers).toEqual({
       "User-Agent": expect.stringMatching(
-        /^antigravity\/cli\/1\.1\.3 \(aidev_client; os_type=.+; arch=.+; auth_method=consumer\)$/,
+        /^antigravity\/cli\/1\.1\.5 \(aidev_client; os_type=.+; arch=.+; auth_method=consumer\)$/,
       ),
       Authorization: "Bearer token",
       "Content-Type": "application/json",

packages/core/src/transform/model-resolver.test.ts

@@ -69,6 +69,22 @@ describe("resolveModelWithTier", () => {
     });
   });
 
+  describe("Gemini 3.6 Flash Antigravity routes", () => {
+    it.each([
+      ["antigravity-gemini-3.6-flash", "gemini-3.6-flash-medium", 4000, "medium"],
+      ["antigravity-gemini-3.6-flash-low", "gemini-3.6-flash-low", 1000, "low"],
+      ["antigravity-gemini-3.6-flash-medium", "gemini-3.6-flash-medium", 4000, "medium"],
+      ["antigravity-gemini-3.6-flash-high", "gemini-3.6-flash-high", 10000, "high"],
+    ])("maps %s to the captured AGY route", (requestedModel, actualModel, thinkingBudget, tier) => {
+      const result = resolveModelWithTier(requestedModel);
+      expect(result.actualModel).toBe(actualModel);
+      expect(result.thinkingBudget).toBe(thinkingBudget);
+      expect(result.thinkingLevel).toBeUndefined();
+      expect(result.tier).toBe(tier);
+      expect(result.quotaPreference).toBe("antigravity");
+    });
+  });
+
   describe("All Gemini models default to antigravity quota", () => {
     it("gemini-2.5-flash defaults to antigravity", () => {
       const result = resolveModelWithTier("gemini-2.5-flash");
@@ -342,6 +358,14 @@ describe("Issue #103: resolveModelForHeaderStyle", () => {
       expect(result.thinkingLevel).toBeUndefined();
       expect(result.quotaPreference).toBe("antigravity");
     });
+
+    it("maps gemini-3.6-flash to the captured agy medium Antigravity model", () => {
+      const result = resolveModelForHeaderStyle("gemini-3.6-flash", "antigravity");
+      expect(result.actualModel).toBe("gemini-3.6-flash-medium");
+      expect(result.thinkingBudget).toBe(4000);
+      expect(result.thinkingLevel).toBeUndefined();
+      expect(result.quotaPreference).toBe("antigravity");
+    });
   });
 
   describe("quota fallback from antigravity to gemini-cli", () => {