diff --git a/src/plugins/plugin-api.js b/src/plugins/plugin-api.js
new file mode 100644
index 0000000..6b89d10
--- /dev/null
+++ b/src/plugins/plugin-api.js
@@ -0,0 +1,23 @@
+class PluginAPI {
+  /**
+   * Called when the plugin is discovered and loaded.
+   * Receives a scoped context object with APIs.
+   * @param {object} context - Plugin context (sidebar, commands, settings, etc.)
+   */
+  init(context) {
+    this.context = context;
+  }
+
+  /** Called when the plugin is activated (e.g., sidebar panel clicked). */
+  activate() {}
+
+  /** Called when the plugin is deactivated. */
+  deactivate() {}
+
+  /** Returns the parsed manifest.json for this plugin. */
+  getManifest() {
+    return this._manifest || null;
+  }
+}
+
+module.exports = { PluginAPI };
diff --git a/tests/plugin-api.test.js b/tests/plugin-api.test.js
new file mode 100644
index 0000000..f83eabf
--- /dev/null
+++ b/tests/plugin-api.test.js
@@ -0,0 +1,29 @@
+const { PluginAPI } = require('../src/plugins/plugin-api');
+
+describe('PluginAPI', () => {
+  test('has default no-op lifecycle methods', () => {
+    const plugin = new PluginAPI();
+    expect(() => plugin.init({})).not.toThrow();
+    expect(() => plugin.activate()).not.toThrow();
+    expect(() => plugin.deactivate()).not.toThrow();
+  });
+
+  test('getManifest returns null by default', () => {
+    const plugin = new PluginAPI();
+    expect(plugin.getManifest()).toBeNull();
+  });
+
+  test('subclass can override init', () => {
+    let called = false;
+    class MyPlugin extends PluginAPI {
+      init(context) {
+        called = true;
+        this.context = context;
+      }
+    }
+    const p = new MyPlugin();
+    p.init({ foo: 'bar' });
+    expect(called).toBe(true);
+    expect(p.context.foo).toBe('bar');
+  });
+});