From 6d3e4764ccc5c3444b55f0ab9e1a723892a40547 Mon Sep 17 00:00:00 2001
From: Sehoon Shon <sshon@google.com>
Date: Thu, 19 Mar 2026 00:30:10 -0400
Subject: [PATCH] feat(cli): support extension installation for teleportation

---
 packages/cli/src/config/extension-manager.ts | 19 +++++++++
 packages/cli/src/config/extension.ts         |  5 +++
 packages/core/src/utils/extensionLoader.ts   | 44 ++++++++++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/packages/cli/src/config/extension-manager.ts b/packages/cli/src/config/extension-manager.ts
index 2c46a845e6..9001ed8cb5 100644
--- a/packages/cli/src/config/extension-manager.ts
+++ b/packages/cli/src/config/extension-manager.ts
@@ -51,6 +51,7 @@ import {
   type HookDefinition,
   type HookEventName,
   type ResolvedExtensionSetting,
+  type TrajectoryProvider,
   coreEvents,
   applyAdminAllowlist,
   getAdminBlockedMcpServersMessage,
@@ -957,6 +958,23 @@ Would you like to attempt to install via "git clone" instead?`,
         );
       }
 
+      let trajectoryProviderModule: TrajectoryProvider | undefined;
+      if (config.trajectoryProvider) {
+        try {
+          const expectedPath = path.resolve(
+            effectiveExtensionPath,
+            config.trajectoryProvider,
+          );
+          // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+          trajectoryProviderModule = (await import(expectedPath))
+            .default as TrajectoryProvider;
+        } catch (e) {
+          debugLogger.warn(
+            `Failed to import trajectoryProvider at ${config.trajectoryProvider} for extension ${config.name}: ${getErrorMessage(e)}`,
+          );
+        }
+      }
+
       return {
         name: config.name,
         version: config.version,
@@ -980,6 +998,7 @@ Would you like to attempt to install via "git clone" instead?`,
         rules,
         checkers,
         plan: config.plan,
+        trajectoryProviderModule,
       };
     } catch (e) {
       const extName = path.basename(extensionDir);
diff --git a/packages/cli/src/config/extension.ts b/packages/cli/src/config/extension.ts
index 564c4fbb6f..2c8763c0bf 100644
--- a/packages/cli/src/config/extension.ts
+++ b/packages/cli/src/config/extension.ts
@@ -46,6 +46,11 @@ export interface ExtensionConfig {
    * Used to migrate an extension to a new repository source.
    */
   migratedTo?: string;
+  /**
+   * Path to a module that implements the TrajectoryProvider interface.
+   * Used for importing binary chat histories like Jetski Teleportation.
+   */
+  trajectoryProvider?: string;
 }
 
 export interface ExtensionUpdateInfo {
diff --git a/packages/core/src/utils/extensionLoader.ts b/packages/core/src/utils/extensionLoader.ts
index 053d4c2b13..05fad2f476 100644
--- a/packages/core/src/utils/extensionLoader.ts
+++ b/packages/core/src/utils/extensionLoader.ts
@@ -242,6 +242,50 @@ export abstract class ExtensionLoader {
     await this.stopExtension(extension);
     await this.startExtension(extension);
   }
+
+  /**
+   * Returns the most recent session from all extensions if it's within the threshold.
+   */
+  async getRecentExternalSession(
+    workspaceUri?: string,
+    thresholdMs: number = 10 * 60 * 1000,
+  ): Promise<{ prefix: string; id: string; displayName?: string } | null> {
+    const activeExtensions = this.getExtensions().filter((e) => e.isActive);
+    let mostRecent: {
+      prefix: string;
+      id: string;
+      displayName?: string;
+      mtime: number;
+    } | null = null;
+
+    for (const extension of activeExtensions) {
+      if (extension.trajectoryProviderModule) {
+        try {
+          const sessions =
+            await extension.trajectoryProviderModule.listSessions(workspaceUri);
+          for (const s of sessions) {
+            const mtime = new Date(s.mtime).getTime();
+            if (!mostRecent || mtime > mostRecent.mtime) {
+              mostRecent = {
+                prefix: extension.trajectoryProviderModule.prefix || '',
+                id: s.id,
+                displayName: s.displayName,
+                mtime,
+              };
+            }
+          }
+        } catch (_e) {
+          // Ignore extension errors
+        }
+      }
+    }
+
+    if (mostRecent && Date.now() - mostRecent.mtime < thresholdMs) {
+      return mostRecent;
+    }
+
+    return null;
+  }
 }
 
 export interface ExtensionEvents {