From 4f0cfc799ea61b616290d8cfc23cce01fffc1e95 Mon Sep 17 00:00:00 2001
From: zu <klineko@icloud.com>
Date: Sat, 28 Feb 2026 15:56:06 +0800
Subject: [PATCH] feat: add Gemini 3.1 Pro support for google-antigravity
 provider
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- Add gemini-3.1-pro-high and gemini-3.1-pro-low to antigravity model registry
- Update DEFAULT_ANTIGRAVITY_VERSION from 1.15.8 to 1.18.0
  (Google sandbox requires UA >= 1.18.0 for Gemini 3.1 models)
- Gemini 3 Pro has been deprecated by Google ('please switch to 3.1')

Verified via direct API testing against the Antigravity sandbox endpoint:
  - gemini-3.1-pro-low with UA 1.18.0: 200 OK ✅
  - gemini-3.1-pro-high with UA 1.18.0: 200 OK ✅
  - gemini-3.1-pro-low with UA 1.15.8: 'upgrade to latest version' ❌
  - gemini-3-pro-low: 'switch to Gemini 3.1 Pro' (deprecated)
---
 packages/ai/scripts/generate-models.ts        | 24 +++++++++++++
 packages/ai/src/models.generated.ts           | 34 +++++++++++++++++++
 .../ai/src/providers/google-gemini-cli.ts     |  2 +-
 3 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/packages/ai/scripts/generate-models.ts b/packages/ai/scripts/generate-models.ts
index b0b201f55..8d02ddcb1 100644
--- a/packages/ai/scripts/generate-models.ts
+++ b/packages/ai/scripts/generate-models.ts
@@ -1031,6 +1031,30 @@ async function generateModels() {
 	// Uses sandbox endpoint and different OAuth credentials for access to additional models
 	const ANTIGRAVITY_ENDPOINT = "https://daily-cloudcode-pa.sandbox.googleapis.com";
 	const antigravityModels: Model<"google-gemini-cli">[] = [
+		{
+			id: "gemini-3.1-pro-high",
+			name: "Gemini 3.1 Pro High (Antigravity)",
+			api: "google-gemini-cli",
+			provider: "google-antigravity",
+			baseUrl: ANTIGRAVITY_ENDPOINT,
+			reasoning: true,
+			input: ["text", "image"],
+			cost: { input: 2, output: 12, cacheRead: 0.2, cacheWrite: 2.375 },
+			contextWindow: 1048576,
+			maxTokens: 65535,
+		},
+		{
+			id: "gemini-3.1-pro-low",
+			name: "Gemini 3.1 Pro Low (Antigravity)",
+			api: "google-gemini-cli",
+			provider: "google-antigravity",
+			baseUrl: ANTIGRAVITY_ENDPOINT,
+			reasoning: true,
+			input: ["text", "image"],
+			cost: { input: 2, output: 12, cacheRead: 0.2, cacheWrite: 2.375 },
+			contextWindow: 1048576,
+			maxTokens: 65535,
+		},
 		{
 			id: "gemini-3-pro-high",
 			name: "Gemini 3 Pro High (Antigravity)",
diff --git a/packages/ai/src/models.generated.ts b/packages/ai/src/models.generated.ts
index f8062ad58..42c99a88e 100644
--- a/packages/ai/src/models.generated.ts
+++ b/packages/ai/src/models.generated.ts
@@ -3394,6 +3394,40 @@ export const MODELS = {
 			contextWindow: 1048576,
 			maxTokens: 65535,
 		} satisfies Model<"google-gemini-cli">,
+		"gemini-3.1-pro-high": {
+			id: "gemini-3.1-pro-high",
+			name: "Gemini 3.1 Pro High (Antigravity)",
+			api: "google-gemini-cli",
+			provider: "google-antigravity",
+			baseUrl: "https://daily-cloudcode-pa.sandbox.googleapis.com",
+			reasoning: true,
+			input: ["text", "image"],
+			cost: {
+				input: 2,
+				output: 12,
+				cacheRead: 0.2,
+				cacheWrite: 2.375,
+			},
+			contextWindow: 1048576,
+			maxTokens: 65535,
+		} satisfies Model<"google-gemini-cli">,
+		"gemini-3.1-pro-low": {
+			id: "gemini-3.1-pro-low",
+			name: "Gemini 3.1 Pro Low (Antigravity)",
+			api: "google-gemini-cli",
+			provider: "google-antigravity",
+			baseUrl: "https://daily-cloudcode-pa.sandbox.googleapis.com",
+			reasoning: true,
+			input: ["text", "image"],
+			cost: {
+				input: 2,
+				output: 12,
+				cacheRead: 0.2,
+				cacheWrite: 2.375,
+			},
+			contextWindow: 1048576,
+			maxTokens: 65535,
+		} satisfies Model<"google-gemini-cli">,
 		"gpt-oss-120b-medium": {
 			id: "gpt-oss-120b-medium",
 			name: "GPT-OSS 120B Medium (Antigravity)",
diff --git a/packages/ai/src/providers/google-gemini-cli.ts b/packages/ai/src/providers/google-gemini-cli.ts
index 7a877ddb4..597295d79 100644
--- a/packages/ai/src/providers/google-gemini-cli.ts
+++ b/packages/ai/src/providers/google-gemini-cli.ts
@@ -72,7 +72,7 @@ const GEMINI_CLI_HEADERS = {
 };
 
 // Headers for Antigravity (sandbox endpoint) - requires specific User-Agent
-const DEFAULT_ANTIGRAVITY_VERSION = "1.15.8";
+const DEFAULT_ANTIGRAVITY_VERSION = "1.18.0";
 
 function getAntigravityHeaders() {
 	const version = process.env.PI_AI_ANTIGRAVITY_VERSION || DEFAULT_ANTIGRAVITY_VERSION;