Send email when canceling trial proactively

front/lib/email.ts

@@ -189,3 +189,30 @@ export async function sendAdminDataDeletionEmail({
   };
   return sendEmail(email, msg);
 }
+
+export async function sendProactiveTrialCancelledEmail(
+  email: string
+): Promise<void> {
+  const message = {
+    from: {
+      name: "Gabriel Hubert",
+      email: "[email protected]",
+    },
+    subject: "[Dust] Your Pro plan trial has been cancelled early",
+    html: `<p>Hi,</p>
+
+    <p>I'm Gabriel, a cofounder of Dust. Thanks for trying us out with a free trial of the Pro Plan.</p>
+
+    <p>You've not used core features of the product (adding data sources, creating custom assistants) and you haven't used assistant conversations in the past 7 days.
+    As a result, to avoid keeping your payment method on file while you may not intend to convert to our paid plan, we've cancelled your trial ahead of time and won't be charging you.</p>
+
+    <p>If you did intend to continue on Dust, you can sign up again and your trial will pick up where you left off, with 3 days to go before converting to our paid plan.
+    If you'd like to extend further, feel free to just email me.</p>
+
+    <p>Thanks again for trying Dust out. If you have a second, please let me know if you have any thoughts about what we could do to improve Dust for your needs!</p>
+
+    Gabriel`,
+  };
+
+  return sendEmail(email, message);
+}

front/lib/plans/subscription.ts

@@ -3,6 +3,7 @@ import type { PlanType, SubscriptionType } from "@dust-tt/types";
 import type Stripe from "stripe";
 
 import type { Authenticator } from "@app/lib/auth";
+import { sendProactiveTrialCancelledEmail } from "@app/lib/email";
 import { Plan, Subscription, Workspace } from "@app/lib/models";
 import type { PlanAttributes } from "@app/lib/plans/free_plans";
 import { FREE_NO_PLAN_DATA } from "@app/lib/plans/free_plans";
@@ -21,6 +22,7 @@ import {
 import { redisClient } from "@app/lib/redis";
 import { frontSequelize } from "@app/lib/resources/storage";
 import { generateModelSId } from "@app/lib/utils";
+import { getWorkspaceFirstAdmin } from "@app/lib/workspace";
 import { checkWorkspaceActivity } from "@app/lib/workspace_usage";
 import logger from "@app/logger/logger";
 
@@ -487,10 +489,25 @@ export async function maybeCancelInactiveTrials(
   const isWorkspaceActive = await checkWorkspaceActivity(workspace);
 
   if (!isWorkspaceActive) {
-    logger.info({ workspaceId: workspace.sId }, "Canceling inactive trial.");
+    logger.info(
+      { action: "cancelling-trial", workspaceId: workspace.sId },
+      "Cancelling inactive trial."
+    );
 
     await cancelSubscriptionImmediately({
       stripeSubscriptionId,
     });
+
+    const firstAdmin = await getWorkspaceFirstAdmin(workspace);
+    if (!firstAdmin) {
+      logger.info(
+        { action: "cancelling-trial", workspaceId: workspace.sId },
+        "No first adming found -- skipping email."
+      );
+
+      return;
+    }
+
+    await sendProactiveTrialCancelledEmail(firstAdmin.email);
   }
 }

front/lib/workspace.ts

@@ -5,6 +5,8 @@ import type {
 } from "@dust-tt/types";
 
 import type { Workspace } from "@app/lib/models";
+import { User } from "@app/lib/models";
+import { MembershipModel } from "@app/lib/resources/storage/models/membership";
 
 export function renderLightWorkspaceType({
   workspace,
@@ -21,3 +23,20 @@ export function renderLightWorkspaceType({
     role,
   };
 }
+
+// TODO: This belong to the WorkspaceResource.
+export async function getWorkspaceFirstAdmin(workspace: Workspace) {
+  return User.findOne({
+    include: [
+      {
+        model: MembershipModel,
+        where: {
+          role: "admin",
+          workspaceId: workspace.id,
+        },
+        required: true,
+      },
+    ],
+    order: [["createdAt", "ASC"]],
+  });
+}