diff --git a/README.md b/README.md
index 1553ae9..ceb5d6f 100644
--- a/README.md
+++ b/README.md
@@ -54,7 +54,7 @@ Get started in minutes:
 ## How It Works
 
 1. **Security rules** are written in unified markdown format (`sources/` directory)
-2. **Conversion tools** translate rules to IDE-specific formats (Cursor, Windsurf, Copilot, Claude Code)
+2. **Conversion tools** translate rules to IDE-specific formats (Cursor, Windsurf, Copilot, Claude Code, Antigravity)
 3. **Release automation** packages rules into downloadable ZIP files
 4. **AI assistants** reference these rules when generating or reviewing code
 5. **Secure code** is produced automatically without developer intervention
diff --git a/docs/getting-started.md b/docs/getting-started.md
index 81add1a..adcb1d0 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -31,6 +31,11 @@ Before you begin, familiarize yourself with how rules work in your IDE:
     
     :material-book-open-page-variant: [GitHub Copilot Instructions](https://docs.github.com/en/copilot/how-tos/configure-custom-instructions/add-repository-instructions)
 
+=== "Antigravity"
+    Antigravity uses `.agent/rules` for rule configuration.
+
+    :material-book-open-page-variant: [Antigravity Instructions](https://codelabs.developers.google.com/getting-started-google-antigravity#8)
+
 ## Installation
 
 ### Option 1: Download Pre-built Rules (Recommended)
@@ -95,6 +100,7 @@ uv run python src/convert_to_ide_formats.py --source core owasp
 cp -r dist/.cursor/ /path/to/your/project/
 cp -r dist/.windsurf/ /path/to/your/project/
 cp -r dist/.github/ /path/to/your/project/
+cp -r dist/.agent/ /path/to/your/project/
 ```
 
 ## Verify Installation
@@ -103,6 +109,8 @@ After installation, your project structure should include:
 
 ```
 your-project/
+├── .agent/
+│   └── rules/
 ├── .cursor/
 │   └── rules/
 ├── .windsurf/
diff --git a/src/convert_to_ide_formats.py b/src/convert_to_ide_formats.py
index 3c3cab3..1657366 100644
--- a/src/convert_to_ide_formats.py
+++ b/src/convert_to_ide_formats.py
@@ -16,7 +16,7 @@
 from collections import defaultdict
 
 from converter import RuleConverter
-from formats import CursorFormat, WindsurfFormat, CopilotFormat, ClaudeCodeFormat
+from formats import CursorFormat, WindsurfFormat, CopilotFormat, ClaudeCodeFormat, AntigravityFormat
 from utils import get_version_from_pyproject
 from validate_versions import set_plugin_version, set_marketplace_version
 
@@ -128,6 +128,7 @@ def convert_rules(input_path: str, output_dir: str = "dist", include_claudecode:
         CursorFormat(version),
         WindsurfFormat(version),
         CopilotFormat(version),
+        AntigravityFormat(version),
     ]
     
     # Only include Claude Code for core rules (committed plugin)
diff --git a/src/formats/__init__.py b/src/formats/__init__.py
index 4a2a7db..55cc0d0 100644
--- a/src/formats/__init__.py
+++ b/src/formats/__init__.py
@@ -30,6 +30,7 @@
 from formats.windsurf import WindsurfFormat
 from formats.copilot import CopilotFormat
 from formats.claudecode import ClaudeCodeFormat
+from formats.antigravity import AntigravityFormat
 
 __all__ = [
     "BaseFormat",
@@ -38,4 +39,5 @@
     "WindsurfFormat",
     "CopilotFormat",
     "ClaudeCodeFormat",
+    "AntigravityFormat",
 ]
diff --git a/src/formats/antigravity.py b/src/formats/antigravity.py
new file mode 100644
index 0000000..a77ecbd
--- /dev/null
+++ b/src/formats/antigravity.py
@@ -0,0 +1,74 @@
+# Copyright 2025 Cisco Systems, Inc. and its affiliates
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""
+Antigravity Format Implementation
+
+Generates .md rule files for Antigravity with YAML frontmatter.
+"""
+
+from formats.base import BaseFormat, ProcessedRule
+
+
+class AntigravityFormat(BaseFormat):
+    """
+    Antigravity format implementation (.md rule files).
+
+    Antigravity uses .md files with YAML frontmatter containing:
+    - trigger: 'always_on' or 'glob' (activation type)
+    - globs: (if trigger is 'glob') File matching patterns
+    - description: Rule description
+    - version: Rule version
+    
+    Rules use activation types (Always On or Glob) to determine when
+    they apply, similar to Windsurf's implementation.
+    See: https://antigravity.google/docs/rules-workflows
+    """
+
+    def get_format_name(self) -> str:
+        """Return Antigravity format identifier."""
+        return "antigravity"
+
+    def get_file_extension(self) -> str:
+        """Return Antigravity format file extension."""
+        return ".md"
+
+    def get_output_subpath(self) -> str:
+        """Return Antigravity output subdirectory."""
+        return ".agent/rules"
+
+    def generate(self, rule: ProcessedRule, globs: str) -> str:
+        """
+        Generate Antigravity .md format with YAML frontmatter.
+
+        Args:
+            rule: The processed rule to format
+            globs: Glob patterns for file matching
+
+        Returns:
+            Formatted .md content with trigger, globs, description, and version
+        
+        Note:
+            Antigravity rules use activation types:
+            - 'always_on': Rule applies to all files (when alwaysApply is true)
+            - 'glob': Rule applies to files matching glob patterns (language-specific)
+        """
+        yaml_lines = []
+
+        # Use trigger: always_on for rules that should always apply
+        if rule.always_apply:
+            yaml_lines.append("trigger: always_on")
+        else:
+            yaml_lines.append("trigger: glob")
+            yaml_lines.append(f"globs: {globs}")
+
+        # Add description (required by Antigravity spec)
+        desc = self._format_yaml_field("description", rule.description)
+        if desc:
+            yaml_lines.append(desc)
+
+        # Add version
+        yaml_lines.append(f"version: {self.version}")
+
+        return self._build_yaml_frontmatter(yaml_lines, rule.content)