diff --git a/.github/workflows/plugin-api-v2.yml b/.github/workflows/plugin-api-v2.yml
new file mode 100644
index 0000000..7c1876b
--- /dev/null
+++ b/.github/workflows/plugin-api-v2.yml
@@ -0,0 +1,28 @@
+name: plugin-api-v2
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  contract:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
+        with:
+          repository: akashic-plugins/plugin-contracts
+          ref: 24543445c7b99ca63fcd90b5828f754a148b184c
+          path: .plugin-contracts
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+      - name: Check Plugin API v2
+        env:
+          PYTHONPATH: .plugin-contracts
+        run: python -m akashic_plugin_contracts check plugin.py
diff --git a/mcp/requirements.txt b/mcp/requirements.txt
index 6664c6d..3533ce3 100644
--- a/mcp/requirements.txt
+++ b/mcp/requirements.txt
@@ -1 +1 @@
-mcp
+mcp==1.28.1
diff --git a/plugin.py b/plugin.py
index 80e2e25..38b9289 100644
--- a/plugin.py
+++ b/plugin.py
@@ -18,6 +18,7 @@ class SteamConfig(BaseModel):
 
 
 class SteamPlugin(Plugin):
+    api_version = 2
     name = "steam"
     version = "1.1.0"
     desc = "Steam MCP plugin"
@@ -49,7 +50,7 @@ def proactive_sources(self) -> list[ProactiveSourceSpec]:
             )
         ]
 
-    async def initialize(self) -> None:
+    def activate(self) -> None:
         data_dir = self.context.data_dir
         workspace = self.context.workspace
         if data_dir is None or workspace is None: