OUT-3925, OUT-3926 | Extend grouped email system to support IU recipients

[arpandhakal]

Summary

• Wires recipientIuId into bufferGroupedEmailEvent with a separate window query and IU-specific window key format ({iuId}:iu:{uuid}) to avoid collisions with CU keys
• Teaches flushGroupedEmail to group and flush IU buffer rows, sending to recipientInternalUserId in the Copilot notification payload
• Adds isIuEmailEnabled() stub backed by IU_EMAIL_ALWAYS_ENABLED env var so IU emails can be tested locally before OUT-3929 (platform preference flag) ships
• Removes the hard disableEmail block for IU assignees in sendUserTaskNotification, gating it on isIuEmailEnabled() instead
• Fixes buildNotificationDetails to accept an explicit isIuRecipient flag so the payload correctly sets recipientInternalUserId (the old inference from absence-of-email breaks once IUs have email)

Test plan

• Set IU_EMAIL_ALWAYS_ENABLED=true in .env.local
• Assign a task to an IU — confirm a GroupedEmailEvents row is written with recipientIuId set and recipientClientId null
• Wait 5 minutes (or trigger flushGroupedEmail manually) — confirm the email is sent to the IU via recipientInternalUserId
• Assign multiple tasks to the same IU within 5 minutes — confirm a single grouped summary email is sent
• Assign a task to a CU — confirm existing CU grouped email behaviour is unchanged
• With IU_EMAIL_ALWAYS_ENABLED unset — confirm no IU emails are sent (prod-safe)

🤖 Generated with Claude Code

[linear-code]

OUT-3925

OUT-3926

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
tasks-app	Ready	Preview, Comment	Jul 3, 2026 10:18am

[greptile-apps]

Greptile Summary

This PR extends the grouped email buffering system to support Internal User (IU) recipients, gated behind an IU_EMAIL_ALWAYS_ENABLED env flag while the platform preference check (OUT-3929) is pending.

• Wires recipientIuId into bufferGroupedEmailEvent with a separate IU window query and a collision-safe key format ({iuId}:iu:{uuid}); adds groupIuRecipients / markIuRecipientSent / an IU flush loop to flushGroupedEmail that mirrors the existing CU path.
• Adds ReassignedToIU to groupedEventTypeFor and isIuRecipient, fixes buildNotificationDetails to accept an explicit flag (replacing the fragile "no-email → must be IU" inference), and removes the hard disableEmail block for IU assignees in favour of the feature flag.

Confidence Score: 5/5

Safe to merge; the IU email path is entirely behind the IU_EMAIL_ALWAYS_ENABLED flag so prod behaviour is unchanged until explicitly opted in.

The IU flush loop faithfully mirrors the existing CU loop, the window-key namespace prevents collisions, the feature flag correctly gates all buffering through disableEmail, and the three new guard tests cover the key wiring boundaries. The only open item is a type-safety gap in SendGroupedEmailArgs that does not affect any current call site.

src/jobs/notifications/send-grouped-email.ts — the optional recipient fields have no compile-time enforcement that at least one is provided.

Important Files Changed

Filename	Overview
src/app/api/notification/isIuEmailEnabled.ts	New feature-flag helper wrapping iuEmailAlwaysEnabled from config; trivially correct.
src/config/index.ts	Adds iuEmailAlwaysEnabled boolean parsed from IU_EMAIL_ALWAYS_ENABLED env var; straightforward and prod-safe (defaults false).
src/app/api/tasks/task-notifications.service.ts	Replaces hard disableEmail for IU assignees with a flag-gated condition; logic is correct and prod-safe when flag is unset.
src/app/api/notification/notification.service.ts	Adds isIuRecipient derivation, IU-aware buffer routing, ReassignedToIU in groupedEventTypeFor, and explicit isIuRecipient flag in buildNotificationDetails; logic is consistent and the old inference fallback is preserved for unupdated paths.
src/jobs/notifications/flush-grouped-email.ts	Adds parallel IU flush loop with groupIuRecipients, markIuRecipientSent, and IU-specific Sentry breadcrumbs; mirrors the CU loop faithfully. Type in SendGroupedEmailArgs (see inline comment) is the only concern.
src/jobs/notifications/send-grouped-email.ts	Extends SendGroupedEmailArgs with optional recipientInternalUserId; both recipient fields are now optional with no compile-time enforcement that at least one is present.
src/app/api/notification/notification.service.test.ts	Adds three IU wiring guard tests (buffer row shape, in-product routing, disableEmail guard) and updates the groupedEventTypeFor guard for ReassignedToIU; good coverage of the new paths.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant TN as TaskNotificationsService
    participant NS as NotificationService
    participant DB as GroupedEmailEvents (DB)
    participant TQ as Trigger.dev Queue
    participant FG as flushGroupedEmail (job)
    participant CP as Copilot API

    TN->>NS: "create(Assigned/ReassignedToIU, task, {disableEmail: false})"
    NS->>NS: "isIuRecipient = true"
    NS->>NS: "groupedType = ASSIGNED"
    NS->>DB: bufferGroupedEmailEvent (recipientIuId, windowKey: iuId:iu:uuid)
    NS->>TQ: enqueueGroupedEmailFlush (delay 5m)
    NS->>CP: createNotification (inProduct only)

    Note over TQ,FG: 5 minutes later
    TQ->>FG: "flushGroupedEmailRun({workspaceId, windowKey})"
    FG->>DB: readUnsentWindowEvents
    FG->>FG: groupIuRecipients(rows)
    alt single live event
        FG->>CP: sendIndividualEmail (recipientInternalUserId)
    else multiple live events
        FG->>CP: sendGroupedEmail (recipientInternalUserId)
    end
    FG->>DB: markIuRecipientSent
    FG->>DB: deleteWindowRows (sentAt set)

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
    participant TN as TaskNotificationsService
    participant NS as NotificationService
    participant DB as GroupedEmailEvents (DB)
    participant TQ as Trigger.dev Queue
    participant FG as flushGroupedEmail (job)
    participant CP as Copilot API

    TN->>NS: "create(Assigned/ReassignedToIU, task, {disableEmail: false})"
    NS->>NS: "isIuRecipient = true"
    NS->>NS: "groupedType = ASSIGNED"
    NS->>DB: bufferGroupedEmailEvent (recipientIuId, windowKey: iuId:iu:uuid)
    NS->>TQ: enqueueGroupedEmailFlush (delay 5m)
    NS->>CP: createNotification (inProduct only)

    Note over TQ,FG: 5 minutes later
    TQ->>FG: "flushGroupedEmailRun({workspaceId, windowKey})"
    FG->>DB: readUnsentWindowEvents
    FG->>FG: groupIuRecipients(rows)
    alt single live event
        FG->>CP: sendIndividualEmail (recipientInternalUserId)
    else multiple live events
        FG->>CP: sendGroupedEmail (recipientInternalUserId)
    end
    FG->>DB: markIuRecipientSent
    FG->>DB: deleteWindowRows (sentAt set)

Loading

_{Reviews (2): Last reviewed commit: "fix(notifications): buffer ReassignedToI..." | Re-trigger Greptile}

[vercel]

Deployment failed with the following error:

Deploying Serverless Functions to multiple regions is restricted to the Pro and Enterprise plans.

Learn More: https://vercel.link/multiple-function-regions

[arpandhakal]

please review again @greptile

[priosshrsth]

lgtm