diff --git a/.env b/.env
index 8e3473b7e0..8e115d0fe5 100644
--- a/.env
+++ b/.env
@@ -1,5 +1,7 @@
 BILLING_PLAN_ENV=dev
 
+VSCODE_EXTENSION_BASE_URL=vscode://RooVeterinaryInc.roo-cline
+
 # Clerk
 # https://clerk.com/docs/deployments/clerk-environment-variables#sign-in-and-sign-up-redirects
 NEXT_PUBLIC_CLERK_SIGN_IN_URL=/sign-in
diff --git a/src/app/(authenticated)/extension/sign-in/route.ts b/src/app/(authenticated)/extension/sign-in/route.ts
new file mode 100644
index 0000000000..bf5a2565f1
--- /dev/null
+++ b/src/app/(authenticated)/extension/sign-in/route.ts
@@ -0,0 +1,25 @@
+import { getSignInToken } from '@/lib/server/clerk';
+import { Env } from '@/lib/server/env';
+import { auth } from '@clerk/nextjs/server';
+import { redirect } from 'next/navigation';
+import { type NextRequest } from 'next/server';
+
+export async function GET(request: NextRequest) {
+  const authObj = await auth();
+  const userId = authObj.userId;
+  const state = request.nextUrl.searchParams.get('state') || '';
+
+  if (!userId) {
+    throw new Error('not logged in?');
+  }
+
+  const signInToken = await getSignInToken(authObj.userId);
+  if (!signInToken) {
+    throw new Error("couldn't sign in");
+  }
+
+  const url = new URL(`${Env.VSCODE_EXTENSION_BASE_URL}/auth/clerk/callback`);
+  url.searchParams.append('state', state);
+  url.searchParams.append('code', signInToken);
+  redirect(url.href);
+}
diff --git a/src/lib/server/clerk.ts b/src/lib/server/clerk.ts
new file mode 100644
index 0000000000..fe2b3049a7
--- /dev/null
+++ b/src/lib/server/clerk.ts
@@ -0,0 +1,39 @@
+import { Env } from './env';
+import { logger } from './logger';
+
+export async function getSignInToken(
+  userId: string,
+): Promise<string | undefined> {
+  const response = await fetch('https://api.clerk.com/v1/sign_in_tokens', {
+    method: 'POST',
+    headers: {
+      Authorization: `Bearer ${Env.CLERK_SECRET_KEY}`,
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({
+      user_id: userId,
+      // Default expiration is 30 days (2592000 seconds)
+    }),
+  });
+
+  if (!response.ok) {
+    const errorData = await response.json();
+    logger.error({
+      event: 'sign_in_token_creation_failed',
+      error: errorData,
+      userId,
+    });
+
+    return undefined; // probably just throw
+  }
+
+  const data = await response.json();
+
+  logger.info({
+    event: 'sign_in_token_created',
+    userId,
+    data, // TODO: none of this, probably
+  });
+
+  return data.token;
+}
diff --git a/src/lib/server/env.ts b/src/lib/server/env.ts
index 8749ac6308..6912a58da3 100644
--- a/src/lib/server/env.ts
+++ b/src/lib/server/env.ts
@@ -9,6 +9,7 @@ export const Env = createEnv({
     STRIPE_SECRET_KEY: z.string().min(1),
     STRIPE_WEBHOOK_SECRET: z.string().min(1),
     BILLING_PLAN_ENV: z.enum(['dev', 'test', 'prod']),
+    VSCODE_EXTENSION_BASE_URL: z.string().min(1),
   },
   client: {
     NEXT_PUBLIC_APP_URL: z.string().optional(),
@@ -32,6 +33,7 @@ export const Env = createEnv({
     STRIPE_SECRET_KEY: process.env.STRIPE_SECRET_KEY,
     STRIPE_WEBHOOK_SECRET: process.env.STRIPE_WEBHOOK_SECRET,
     BILLING_PLAN_ENV: process.env.BILLING_PLAN_ENV,
+    VSCODE_EXTENSION_BASE_URL: process.env.VSCODE_EXTENSION_BASE_URL,
     NEXT_PUBLIC_APP_URL: process.env.NEXT_PUBLIC_APP_URL,
     NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY:
       process.env.NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY,