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SMS workflow reminder retry count tracking #4

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41 changes: 35 additions & 6 deletions packages/features/ee/workflows/api/scheduleSMSReminders.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -28,10 +28,19 @@ async function handler(req: NextApiRequest, res: NextApiResponse) {
//delete all scheduled sms reminders where scheduled date is past current date
await prisma.workflowReminder.deleteMany({
where: {
method: WorkflowMethods.SMS,
scheduledDate: {
lte: dayjs().toISOString(),
},
OR: [
{
method: WorkflowMethods.SMS,
scheduledDate: {
lte: dayjs().toISOString(),
},
},
{
retryCount: {
gt: 1,
},
},
],
},
});

Expand All @@ -44,8 +53,11 @@ async function handler(req: NextApiRequest, res: NextApiResponse) {
lte: dayjs().add(7, "day").toISOString(),
},
},
select,
})) as PartialWorkflowReminder[];
select: {
...select,
retryCount: true,
},
})) as (PartialWorkflowReminder & { retryCount: number })[];

if (!unscheduledReminders.length) {
res.json({ ok: true });
Expand Down Expand Up @@ -163,9 +175,26 @@ async function handler(req: NextApiRequest, res: NextApiResponse) {
referenceId: scheduledSMS.sid,
},
});
} else {
await prisma.workflowReminder.update({
where: {
id: reminder.id,
},
data: {
retryCount: reminder.retryCount + 1,

@codeant-ai codeant-ai Bot Feb 13, 2026

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Suggestion: Incrementing the retry counter using retryCount: reminder.retryCount + 1 is a non-atomic read-modify-write that can lose increments when multiple cron executions overlap, so this should use Prisma's atomic increment operation to be concurrency-safe. [race condition]

Severity Level: Major ⚠️ 
- ⚠️ Lost increments under concurrent cron executions.
- ❌ SMS retry limit enforcement becomes inaccurate.
- ⚠️ Affects POST /api/cron/workflows/scheduleSMSReminders endpoint.
Suggested change
retryCount: reminder.retryCount + 1,
retryCount: {
increment: 1,
},
Steps of Reproduction ✅ 
1. The cron endpoint `/api/cron/workflows/scheduleSMSReminders` is implemented by
`handler` in `packages/features/ee/workflows/api/scheduleSMSReminders.ts:21-202` and
exported via `apps/web/pages/api/cron/workflows/scheduleSMSReminders.ts:1`.

2. On each POST, the handler loads unscheduled SMS reminders via
`prisma.workflowReminder.findMany` at `scheduleSMSReminders.ts:47-60` (filtering by
`method: WorkflowMethods.SMS`, `scheduled: false`, and `scheduledDate`), then loops over
them and calls `twilio.scheduleSMS` at lines 158-166.

3. When `twilio.scheduleSMS` resolves to a falsy value without throwing (e.g. transient
failure where the provider returns no SID), execution enters the `else` block at
`scheduleSMSReminders.ts:168-187`, which updates the row using `data: { retryCount:
reminder.retryCount + 1 }`.

4. If the cron endpoint is invoked concurrently on multiple app instances (or re-invoked
before the previous run finishes) so that two handlers load the same reminder (both
reading `retryCount = 0` from the `findMany` at lines 47-60) and both experience the same
non-throwing failure, then both `update` calls in the `else` block race: each computes
`retryCount: 0 + 1` and writes `1`, resulting in only a single increment being persisted
instead of two. Because cleanup logic at `scheduleSMSReminders.ts:28-44` deletes reminders
only when `retryCount > 1`, this lost increment can cause more send attempts than intended
before the reminder is cleaned up.
Prompt for AI Agent 🤖 
This is a comment left during a code review.

**Path:** packages/features/ee/workflows/api/scheduleSMSReminders.ts
**Line:** 184:184
**Comment:**
	*Race Condition: Incrementing the retry counter using `retryCount: reminder.retryCount + 1` is a non-atomic read-modify-write that can lose increments when multiple cron executions overlap, so this should use Prisma's atomic `increment` operation to be concurrency-safe.

Validate the correctness of the flagged issue. If correct, How can I resolve this? If you propose a fix, implement it and please make it concise.
👍 | 👎

},
});
}
}
} catch (error) {
await prisma.workflowReminder.update({
where: {
id: reminder.id,
},
data: {
retryCount: reminder.retryCount + 1,

@codeant-ai codeant-ai Bot Feb 13, 2026

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Suggestion: The retry counter increment in the error handler also uses retryCount: reminder.retryCount + 1, which can drop increments under concurrent runs of the cron job, so it should likewise use an atomic increment to ensure retries are counted correctly. [race condition]

Severity Level: Major ⚠️ 
- ⚠️ Retry counts inaccurate when provider errors occur.
- ❌ SMS reminders may exceed intended maximum retry attempts.
- ⚠️ Affects POST /api/cron/workflows/scheduleSMSReminders endpoint.
Suggested change
retryCount: reminder.retryCount + 1,
retryCount: {
increment: 1,
},
Steps of Reproduction ✅ 
1. The same cron handler in
`packages/features/ee/workflows/api/scheduleSMSReminders.ts:21-202` iterates over
unscheduled SMS reminders and calls `twilio.scheduleSMS` (lines 158-166); if this call
throws (e.g. network error), execution jumps to the `catch` block at lines 189-198.

2. In the `catch` block, the reminder's `retryCount` is updated via
`prisma.workflowReminder.update` with `data: { retryCount: reminder.retryCount + 1 }` at
`scheduleSMSReminders.ts:190-197`, using the `retryCount` value that was originally read
in the `findMany` at lines 47-60.

3. If two instances of the cron endpoint `/api/cron/workflows/scheduleSMSReminders` run
concurrently and both load the same reminder (each seeing the same `retryCount` value from
`findMany`) and both encounter a thrown error from `twilio.scheduleSMS`, they will each
execute the `catch` block and issue concurrent `update` statements writing `retryCount` to
the same computed value (e.g. both write `1` instead of incrementing from `0` to `2`).

4. Because cleanup at `scheduleSMSReminders.ts:28-44` relies on `retryCount > 1` to stop
retrying and delete reminders, these lost increments from the non-atomic `retryCount:
reminder.retryCount + 1` in the `catch` block can allow additional unintended retry
attempts or leave reminders in the system longer than the intended maximum number of
failures.
Prompt for AI Agent 🤖 
This is a comment left during a code review.

**Path:** packages/features/ee/workflows/api/scheduleSMSReminders.ts
**Line:** 195:195
**Comment:**
	*Race Condition: The retry counter increment in the error handler also uses `retryCount: reminder.retryCount + 1`, which can drop increments under concurrent runs of the cron job, so it should likewise use an atomic `increment` to ensure retries are counted correctly.

Validate the correctness of the flagged issue. If correct, How can I resolve this? If you propose a fix, implement it and please make it concise.
👍 | 👎

},
});
console.log(`Error scheduling SMS with error ${error}`);
}
}
Expand Down
2 changes: 2 additions & 0 deletions packages/prisma/migrations/20240508134359_add_retry_count_to_workflow_reminder/migration.sql
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Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
-- AlterTable
ALTER TABLE "WorkflowReminder" ADD COLUMN "retryCount" INTEGER NOT NULL DEFAULT 0;
1 change: 1 addition & 0 deletions packages/prisma/schema.prisma
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Original file line number Diff line number Diff line change
Expand Up @@ -997,6 +997,7 @@ model WorkflowReminder {
cancelled Boolean?
seatReferenceId String?
isMandatoryReminder Boolean? @default(false)
retryCount Int @default(0)

@@index([bookingUid])
@@index([workflowStepId])
Expand Down