docs: 添加 Antigravity 使用说明

README.md

@@ -283,6 +283,36 @@ npm run dev
 
 ---
 
+## Antigravity Support
+
+Sub2API supports [Antigravity](https://antigravity.so/) accounts. After authorization, dedicated endpoints are available for Claude and Gemini models.
+
+### Dedicated Endpoints
+
+| Endpoint | Model |
+|----------|-------|
+| `/antigravity/v1/messages` | Claude models |
+| `/antigravity/v1beta/` | Gemini models |
+
+### Claude Code Configuration
+
+```bash
+export ANTHROPIC_BASE_URL="http://localhost:8080/antigravity"
+export ANTHROPIC_AUTH_TOKEN="sk-xxx"
+```
+
+### Hybrid Scheduling Mode
+
+Antigravity accounts support optional **hybrid scheduling**. When enabled, the general endpoints `/v1/messages` and `/v1beta/` will also route requests to Antigravity accounts.
+
+> **⚠️ Warning**: Anthropic Claude and Antigravity Claude **cannot be mixed within the same conversation context**. Use groups to isolate them properly.
+
+### Usage Recommendations
+
+Antigravity Gemini Pro accounts are prone to 429 rate limiting. We recommend keeping the **ratio of Claude Code terminals to Antigravity Gemini Pro accounts at 1:1 or lower**.
+
+---
+
 ## Project Structure
 
 ```

README_CN.md

@@ -293,6 +293,36 @@ npm run dev
 
 ---
 
+## Antigravity 使用说明
+
+Sub2API 支持 [Antigravity](https://antigravity.so/) 账户，授权后可通过专用端点访问 Claude 和 Gemini 模型。
+
+### 专用端点
+
+| 端点 | 模型 |
+|------|------|
+| `/antigravity/v1/messages` | Claude 模型 |
+| `/antigravity/v1beta/` | Gemini 模型 |
+
+### Claude Code 配置示例
+
+```bash
+export ANTHROPIC_BASE_URL="http://localhost:8080/antigravity"
+export ANTHROPIC_AUTH_TOKEN="sk-xxx"
+```
+
+### 混合调度模式
+
+Antigravity 账户支持可选的**混合调度**功能。开启后，通用端点 `/v1/messages` 和 `/v1beta/` 也会调度该账户。
+
+> **⚠️ 注意**：Anthropic Claude 和 Antigravity Claude **不能在同一上下文中混合使用**，请通过分组功能做好隔离。
+
+### 使用建议
+
+实测 Antigravity Gemini Pro 账户较容易触发 429 限流。建议 **Claude Code 终端数量与 Antigravity Gemini Pro 账户数量的比例保持在 1:1 或更低**。
+
+---
+
 ## 项目结构
 
 ```