diff --git a/.github/workflows/scripts/create-github-release.sh b/.github/workflows/scripts/create-github-release.sh
index c09a255ba..32a29c281 100644
--- a/.github/workflows/scripts/create-github-release.sh
+++ b/.github/workflows/scripts/create-github-release.sh
@@ -46,5 +46,7 @@ gh release create "$VERSION" \
   .genreleases/spec-kit-template-shai-ps-"$VERSION".zip \
   .genreleases/spec-kit-template-q-sh-"$VERSION".zip \
   .genreleases/spec-kit-template-q-ps-"$VERSION".zip \
+  .genreleases/spec-kit-template-agy-sh-"$VERSION".zip \
+  .genreleases/spec-kit-template-agy-ps-"$VERSION".zip \
   --title "Spec Kit Templates - $VERSION_NO_V" \
   --notes-file release_notes.md
diff --git a/.github/workflows/scripts/create-release-packages.sh b/.github/workflows/scripts/create-release-packages.sh
index 1f5c6e51b..86435634b 100755
--- a/.github/workflows/scripts/create-release-packages.sh
+++ b/.github/workflows/scripts/create-release-packages.sh
@@ -211,13 +211,16 @@ build_variant() {
     q)
       mkdir -p "$base_dir/.amazonq/prompts"
       generate_commands q md "\$ARGUMENTS" "$base_dir/.amazonq/prompts" "$script" ;;
+    agy)
+      mkdir -p "$base_dir/.agent/workflows"
+      generate_commands agy md "\$ARGUMENTS" "$base_dir/.agent/workflows" "$script" ;;
   esac
   ( cd "$base_dir" && zip -r "../spec-kit-template-${agent}-${script}-${NEW_VERSION}.zip" . )
   echo "Created $GENRELEASES_DIR/spec-kit-template-${agent}-${script}-${NEW_VERSION}.zip"
 }
 
 # Determine agent list
-ALL_AGENTS=(claude gemini copilot cursor-agent qwen opencode windsurf codex kilocode auggie roo codebuddy amp shai q)
+ALL_AGENTS=(claude gemini copilot cursor-agent qwen opencode windsurf codex kilocode auggie roo codebuddy amp shai q agy)
 ALL_SCRIPTS=(sh ps)
 
 norm_list() {
diff --git a/README.md b/README.md
index c3dcdf269..60f7cefd9 100644
--- a/README.md
+++ b/README.md
@@ -151,6 +151,7 @@ Want to see Spec Kit in action? Watch our [video overview](https://www.youtube.c
 | [Amazon Q Developer CLI](https://aws.amazon.com/developer/learning/q-developer-cli/) | ⚠️ | Amazon Q Developer CLI [does not support](https://github.com/aws/amazon-q-developer-cli/issues/3064) custom arguments for slash commands. |
 | [Amp](https://ampcode.com/) | ✅ | |
 | [SHAI (OVHcloud)](https://github.com/ovh/shai) | ✅ | |
+| [Antigravity (agy)](https://antigravity.google/) | ✅ | |
 
 ## 🔧 Specify CLI Reference
 
@@ -168,7 +169,7 @@ The `specify` command supports the following options:
 | Argument/Option        | Type     | Description                                                                  |
 |------------------------|----------|------------------------------------------------------------------------------|
 | `<project-name>`       | Argument | Name for your new project directory (optional if using `--here`, or use `.` for current directory) |
-| `--ai`                 | Option   | AI assistant to use: `claude`, `gemini`, `copilot`, `cursor-agent`, `qwen`, `opencode`, `codex`, `windsurf`, `kilocode`, `auggie`, `roo`, `codebuddy`, `amp`, `shai`, or `q` |
+| `--ai`                 | Option   | AI assistant to use: `claude`, `gemini`, `copilot`, `cursor-agent`, `qwen`, `opencode`, `codex`, `windsurf`, `kilocode`, `auggie`, `roo`, `codebuddy`, `amp`, `shai`, `q`, or `agy` |
 | `--script`             | Option   | Script variant to use: `sh` (bash/zsh) or `ps` (PowerShell)                 |
 | `--ignore-agent-tools` | Flag     | Skip checks for AI agent tools like Claude Code                             |
 | `--no-git`             | Flag     | Skip git repository initialization                                          |
diff --git a/scripts/bash/update-agent-context.sh b/scripts/bash/update-agent-context.sh
index e0aa1de40..65b778605 100644
--- a/scripts/bash/update-agent-context.sh
+++ b/scripts/bash/update-agent-context.sh
@@ -30,12 +30,12 @@
 #
 # 5. Multi-Agent Support
 #    - Handles agent-specific file paths and naming conventions
-#    - Supports: Claude, Gemini, Copilot, Cursor, Qwen, opencode, Codex, Windsurf, Kilo Code, Auggie CLI, Roo Code, CodeBuddy CLI, Amp, SHAI, or Amazon Q Developer CLI
+#    - Supports: Claude, Gemini, Copilot, Cursor, Qwen, opencode, Codex, Windsurf, Kilo Code, Auggie CLI, Roo Code, CodeBuddy CLI, Amp, SHAI, Amazon Q Developer CLI, or Antigravity
 #    - Can update single agents or all existing agent files
 #    - Creates default Claude file if no agent files exist
 #
 # Usage: ./update-agent-context.sh [agent_type]
-# Agent types: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|shai|q
+# Agent types: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|shai|q|agy
 # Leave empty to update all existing agent files
 
 set -e
@@ -73,6 +73,7 @@ CODEBUDDY_FILE="$REPO_ROOT/CODEBUDDY.md"
 AMP_FILE="$REPO_ROOT/AGENTS.md"
 SHAI_FILE="$REPO_ROOT/SHAI.md"
 Q_FILE="$REPO_ROOT/AGENTS.md"
+AGY_FILE="$REPO_ROOT/.agent/rules/specify-rules.md"
 
 # Template file
 TEMPLATE_FILE="$REPO_ROOT/.specify/templates/agent-file-template.md"
@@ -625,9 +626,12 @@ update_specific_agent() {
         q)
             update_agent_file "$Q_FILE" "Amazon Q Developer CLI"
             ;;
+        agy)
+            update_agent_file "$AGY_FILE" "Antigravity"
+            ;;
         *)
             log_error "Unknown agent type '$agent_type'"
-            log_error "Expected: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|amp|shai|q"
+            log_error "Expected: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|amp|shai|q|agy"
             exit 1
             ;;
     esac
@@ -701,6 +705,11 @@ update_all_existing_agents() {
         update_agent_file "$Q_FILE" "Amazon Q Developer CLI"
         found_agent=true
     fi
+
+    if [[ -f "$AGY_FILE" ]]; then
+        update_agent_file "$AGY_FILE" "Antigravity"
+        found_agent=true
+    fi
     
     # If no agent files exist, create a default Claude file
     if [[ "$found_agent" == false ]]; then
@@ -726,7 +735,7 @@ print_summary() {
     
     echo
 
-    log_info "Usage: $0 [claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|codebuddy|shai|q]"
+    log_info "Usage: $0 [claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|codebuddy|shai|q|agy]"
 }
 
 #==============================================================================
diff --git a/scripts/powershell/update-agent-context.ps1 b/scripts/powershell/update-agent-context.ps1
index ea5654cce..751fd836d 100644
--- a/scripts/powershell/update-agent-context.ps1
+++ b/scripts/powershell/update-agent-context.ps1
@@ -9,7 +9,7 @@ Mirrors the behavior of scripts/bash/update-agent-context.sh:
  2. Plan Data Extraction
  3. Agent File Management (create from template or update existing)
  4. Content Generation (technology stack, recent changes, timestamp)
- 5. Multi-Agent Support (claude, gemini, copilot, cursor-agent, qwen, opencode, codex, windsurf, kilocode, auggie, roo, codebuddy, amp, shai, q)
+ 5. Multi-Agent Support (claude, gemini, copilot, cursor-agent, qwen, opencode, codex, windsurf, kilocode, auggie, roo, codebuddy, amp, shai, q, agy)
 
 .PARAMETER AgentType
 Optional agent key to update a single agent. If omitted, updates all existing agent files (creating a default Claude file if none exist).
@@ -25,7 +25,7 @@ Relies on common helper functions in common.ps1
 #>
 param(
     [Parameter(Position=0)]
-    [ValidateSet('claude','gemini','copilot','cursor-agent','qwen','opencode','codex','windsurf','kilocode','auggie','roo','codebuddy','amp','shai','q')]
+    [ValidateSet('claude','gemini','copilot','cursor-agent','qwen','opencode','codex','windsurf','kilocode','auggie','roo','codebuddy','amp','shai','q','agy')]
     [string]$AgentType
 )
 
@@ -58,6 +58,7 @@ $CODEBUDDY_FILE = Join-Path $REPO_ROOT 'CODEBUDDY.md'
 $AMP_FILE      = Join-Path $REPO_ROOT 'AGENTS.md'
 $SHAI_FILE     = Join-Path $REPO_ROOT 'SHAI.md'
 $Q_FILE        = Join-Path $REPO_ROOT 'AGENTS.md'
+$AGY_FILE      = Join-Path $REPO_ROOT '.agent/rules/specify-rules.md'
 
 $TEMPLATE_FILE = Join-Path $REPO_ROOT '.specify/templates/agent-file-template.md'
 
@@ -384,7 +385,8 @@ function Update-SpecificAgent {
         'amp'      { Update-AgentFile -TargetFile $AMP_FILE      -AgentName 'Amp' }
         'shai'     { Update-AgentFile -TargetFile $SHAI_FILE     -AgentName 'SHAI' }
         'q'        { Update-AgentFile -TargetFile $Q_FILE        -AgentName 'Amazon Q Developer CLI' }
-        default { Write-Err "Unknown agent type '$Type'"; Write-Err 'Expected: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|codebuddy|amp|shai|q'; return $false }
+        'agy'      { Update-AgentFile -TargetFile $AGY_FILE      -AgentName 'Antigravity' }
+        default { Write-Err "Unknown agent type '$Type'"; Write-Err 'Expected: claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|codebuddy|amp|shai|q|agy'; return $false }
     }
 }
 
@@ -404,6 +406,7 @@ function Update-AllExistingAgents {
     if (Test-Path $CODEBUDDY_FILE) { if (-not (Update-AgentFile -TargetFile $CODEBUDDY_FILE -AgentName 'CodeBuddy CLI')) { $ok = $false }; $found = $true }
     if (Test-Path $SHAI_FILE)     { if (-not (Update-AgentFile -TargetFile $SHAI_FILE     -AgentName 'SHAI')) { $ok = $false }; $found = $true }
     if (Test-Path $Q_FILE)        { if (-not (Update-AgentFile -TargetFile $Q_FILE        -AgentName 'Amazon Q Developer CLI')) { $ok = $false }; $found = $true }
+    if (Test-Path $AGY_FILE)      { if (-not (Update-AgentFile -TargetFile $AGY_FILE      -AgentName 'Antigravity')) { $ok = $false }; $found = $true }
     if (-not $found) {
         Write-Info 'No existing agent files found, creating default Claude file...'
         if (-not (Update-AgentFile -TargetFile $CLAUDE_FILE -AgentName 'Claude Code')) { $ok = $false }
@@ -418,7 +421,7 @@ function Print-Summary {
     if ($NEW_FRAMEWORK) { Write-Host "  - Added framework: $NEW_FRAMEWORK" }
     if ($NEW_DB -and $NEW_DB -ne 'N/A') { Write-Host "  - Added database: $NEW_DB" }
     Write-Host ''
-    Write-Info 'Usage: ./update-agent-context.ps1 [-AgentType claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|codebuddy|amp|shai|q]'
+    Write-Info 'Usage: ./update-agent-context.ps1 [-AgentType claude|gemini|copilot|cursor-agent|qwen|opencode|codex|windsurf|kilocode|auggie|roo|codebuddy|amp|shai|q|agy]'
 }
 
 function Main {
diff --git a/src/specify_cli/__init__.py b/src/specify_cli/__init__.py
index 2fa6455a2..4f89feda3 100644
--- a/src/specify_cli/__init__.py
+++ b/src/specify_cli/__init__.py
@@ -214,6 +214,12 @@ def _format_rate_limit_error(status_code: int, headers: httpx.Headers, url: str)
         "install_url": "https://github.com/ovh/shai",
         "requires_cli": True,
     },
+    "agy": {
+        "name": "Antigravity",
+        "folder": ".agent/",
+        "install_url": None,
+        "requires_cli": True,
+    },
 }
 
 SCRIPT_TYPE_CHOICES = {"sh": "POSIX Shell (bash/zsh)", "ps": "PowerShell"}
@@ -933,7 +939,7 @@ def ensure_executable_scripts(project_path: Path, tracker: StepTracker | None =
 @app.command()
 def init(
     project_name: str = typer.Argument(None, help="Name for your new project directory (optional if using --here, or use '.' for current directory)"),
-    ai_assistant: str = typer.Option(None, "--ai", help="AI assistant to use: claude, gemini, copilot, cursor-agent, qwen, opencode, codex, windsurf, kilocode, auggie, codebuddy, amp, shai, or q"),
+    ai_assistant: str = typer.Option(None, "--ai", help="AI assistant to use: claude, gemini, copilot, cursor-agent, qwen, opencode, codex, windsurf, kilocode, auggie, codebuddy, amp, shai, q, or agy"),
     script_type: str = typer.Option(None, "--script", help="Script type to use: sh or ps"),
     ignore_agent_tools: bool = typer.Option(False, "--ignore-agent-tools", help="Skip checks for AI agent tools like Claude Code"),
     no_git: bool = typer.Option(False, "--no-git", help="Skip git repository initialization"),