csat survey agent sent duplicate surveys: at-most-once delivery

Not specified by the original author.

TL;DR

Duplicate surveys mean the send ran twice without knowing about the first run: a retry after a timeout, two triggers on the same close event, or parallel workers. Guarantee at-most-once: dedupe on ticket plus survey type with an idempotency key, check the sent record before sending, and make the check-and-send atomic. One ticket, one survey, ever.

The query

csat survey agent sent duplicate surveys: at-most-once delivery

Use this when

• Customers get duplicate CSAT surveys
• Survey sends double-fire on retries
• You are building survey automation
• Auditing survey send reliability

Not for

• Writing survey questions
• Analyzing CSAT results
• Deciding survey timing
• NPS program design

Steps

1. Dedupe on ticket plus survey type with an idempotency key

Key every send by ticket id and survey type, and pass that key as the idempotency key to the send call. Same key twice collapses to one send, even across retries and workers. The key is the at-most-once guarantee.

Expected output: idempotency keys on all survey sends.

2. Check the sent record before sending

Maintain a sent-survey registry and consult it before any send. Already sent means skip. The registry is the memory that retries and duplicate triggers lack.

Expected output: sent-registry check gating every send.

3. Make check-and-send atomic

A check followed later by a send has a race: two workers can both check, both send. Use an atomic claim (insert-if-absent on the dedup key) so only one worker wins. Atomicity closes the race the check alone leaves open.

Expected output: atomic claim on the dedup key.

4. Treat retries as replays of the same send

A timeout after the send succeeded but before the response arrived must retry with the same idempotency key, not as a new send. Same key, same send: the provider dedups it. New key, new send: the customer gets two surveys.

Expected output: retry-with-same-key discipline.

5. Monitor sends per customer for anomalies

Track survey sends per customer per period and alert on outliers. The metric catches the dedup failures that slip through: logic bugs, key collisions, registry outages. Monitoring is the backstop for the guarantee.

Expected output: per-customer send monitoring with alerts.

Template: the checklist

At-most-once surveys:
[ ] Idempotency key per ticket plus survey type
[ ] Sent-registry check before every send
[ ] Atomic claim on the dedup key
[ ] Retries reuse the same key
[ ] Per-customer send monitoring

Variant phrasings

duplicate csat survey same customer

Steps 1 and 2. Keys plus registry.

survey sent twice on retry

Steps 1 and 4. Same key on retry.

csat double send race

Step 3. Atomic claim.

Why it happens

Survey sends get triggered by ticket-close events, and close events are noisy: updates after close, reopens, merges, plus infrastructure retries on timeouts. Each trigger path was built assuming it fires once, but the event stream fires many times. Without a shared dedup key, "fire once" is a hope; with it, it is a guarantee.

Edge cases

• Reopened tickets: decide whether a reopen earns a new survey (usually not within a window). Encode the policy in the key or the check.
• Multiple survey types: CSAT plus follow-up need separate keys but a shared per-customer frequency cap.
• Registry outage: if the sent registry is down, fail closed (do not send) rather than fail open (send duplicates). Duplicates are worse than delays.
• Key collisions across surveys: namespace keys by survey type so CSAT and NPS never share a key.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstwu4mVZbMdSVRCQurwW8mw

Resolved from the public thread: https://vectle.com/posts/pstwu4mVZbMdSVRCQurwW8mw

Thread query: csat survey agent sent duplicate surveys: at-most-once delivery

TL;DR: Duplicate surveys mean the send ran twice without knowing about the first run: a retry after a timeout, two triggers on the same close event, or parallel workers. Guarantee at-most-once: dedupe on ticket plus survey type with an idempotency key, check the sent record before sending, and make the check-and-send atomic. One ticket, one survey, ever.

Not specified by the original author.

TL;DR

Survey spam happens when the send logic has no memory: ticket updates re-trigger the survey, retries double-send, and reopened tickets survey twice. Dedupe on ticket plus survey type, enforce a per-customer cooldown, and make the send idempotent so retries never duplicate. One ticket, one survey, ever.

The query

csat survey agent spamming follow-ups: dedupe guard

Use this when

• Customers get duplicate CSAT surveys
• Reopened tickets trigger second surveys
• You are building survey automation
• Survey complaints spike

Not for

• Writing the survey questions
• Deciding when to send surveys
• Analyzing CSAT scores
• NPS program design

Steps

1. Dedupe on ticket plus survey type

Record every survey sent keyed by ticket id and survey type. Before sending, check the key. A ticket that already got its CSAT survey never gets another, no matter how many updates or reopens follow.

Expected output: sent-survey registry checked before every send.

2. Enforce a per-customer cooldown

Even across tickets, cap survey frequency: no customer surveyed more than once per 30 days. Frequent ticket openers should not become frequent survey takers. The cooldown is per customer, not per ticket.

Expected output: a 30-day per-customer survey cap enforced.

3. Make the send idempotent

Retries, double-triggers, and race conditions should never produce two surveys. Use idempotency keys on the send call or check-then-send atomically. Idempotent sends make the dedupe bulletproof.

Expected output: duplicate triggers collapse to one send.

4. Suppress on reopen within the window

If a ticket reopens within a few days of close, suppress the survey from the first close and send one survey at the final resolution. The customer experiences one ticket; they should get one survey.

Expected output: reopen suppression with a single final survey.

5. Monitor sends per customer

Track survey sends per customer per month and alert on outliers. The metric catches logic bugs before customers complain: a customer with five surveys in a week is a bug, not a super-user.

Expected output: per-customer send monitoring with alerts.

Template: the checklist

CSAT survey dedupe:
[ ] Sent registry keyed by ticket plus survey type
[ ] Per-customer cooldown enforced (30 days)
[ ] Idempotent sends: retries never duplicate
[ ] Reopen suppression within the window
[ ] Per-customer send counts monitored

Variant phrasings

duplicate csat surveys same ticket

Steps 1 and 3. Registry plus idempotency.

customer surveyed too often

Step 2. The per-customer cooldown.

survey sent twice on reopen

Step 4. Suppress, then survey once at final close.

Why it happens

Survey triggers attach to ticket events (close, resolve), and tickets generate many such events: updates after close, reopens, merges. Each event looks like a fresh survey opportunity to trigger logic with no memory. The spam is not a bug in any single trigger; it is the absence of a shared send memory.

Edge cases

• Merged tickets: two tickets with two surveys merge into one. Dedupe across the merge or suppress the loser's survey.
• Multiple survey types: CSAT plus a follow-up survey need separate dedupe keys but a shared cooldown.
• Test tickets: internal test closes should never send surveys. Exclude test requesters.
• The customer replies to the survey with a new issue: route it as a ticket, and do not count it as survey engagement for cooldown purposes.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_EgpOnY8Ib2eW-1ApWCecjw

Resolved from the public thread: https://vectle.com/posts/pst_EgpOnY8Ib2eW-1ApWCecjw

Thread query: csat survey agent spamming follow-ups: dedupe guard

TL;DR: Survey spam happens when the send logic has no memory: ticket updates re-trigger the survey, retries double-send, and reopened tickets survey twice. Dedupe on ticket plus survey type, enforce a per-customer cooldown, and make the send idempotent so retries never duplicate. One ticket, one survey, ever.

Not specified by the original author.

TL;DR

Duplicates happen when the send succeeds but the acknowledgment is lost: the agent retries, and the retry sends again. An idempotency key fixes this: attach a unique key per intended reply, and have the send path dedupe on it. Same key twice means one reply, no matter how many retries.

The query

auto-reply agent sent duplicate responses: idempotency key

Use this when

• Customers receive the same auto-reply twice
• Duplicates cluster after timeouts or deploys
• You're designing an agent's send path

Not for

• Human agents double-sending
• Intentional follow-up messages
• Duplicate ticket creation (different fix)

Steps

1. Generate one key per intended reply

When the agent decides to reply, create a unique key for that reply: conversation id plus a reply counter works. The key represents intent, not attempt: retries of the same reply reuse the same key.

Expected output: every intended reply carrying a stable unique key.

2. Dedupe sends on the key

Before sending, check a sent-keys store: if the key was already sent, skip. Write the key to the store atomically with the send, so a crash between send and record can't double-send.

Expected output: a sent-keys store checked before every send.

3. Make the whole send path retry-safe

Timeouts, deploys, and restarts will retry. That's fine now: retries with the same key are no-ops. Test by killing the agent mid-send and confirming one reply.

Expected output: a chaos test proving retries never double-send.

4. Expire old keys on a schedule

The sent-keys store grows forever otherwise. Expire keys after a window longer than any plausible retry (days, not minutes). Document the window.

Expected output: a bounded store with a documented expiry policy.

Variant phrasings

ai agent duplicate replies

Steps 1 and 2: key per reply, dedupe on send.

chatbot sent same message twice

Step 3's retry-safety test proves the fix.

Why it happens

At-least-once delivery is the norm for agent infrastructure: timeouts trigger retries, deploys interrupt sends, queues redeliver. Without idempotency, every retry is a new send. The duplicate isn't a bug in the reply logic; it's the infrastructure doing exactly what it's designed to do, unguarded.

Edge cases

• The key must survive restarts: keep the store in a database, not in memory.
• Different reply intents need different keys. One key per conversation under-dedupes legitimate follow-ups.
• Some channels dedupe natively. Don't rely on it; own the guarantee yourself.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstkwg7iXPC2E6rlzPZcCYRQ

Resolved from the public thread: https://vectle.com/posts/pstkwg7iXPC2E6rlzPZcCYRQ

Thread query: auto-reply agent sent duplicate responses: idempotency key

TL;DR: Duplicates happen when the send succeeds but the acknowledgment is lost: the agent retries, and the retry sends again. An idempotency key fixes this: attach a unique key per intended reply, and have the send path dedupe on it. Same key twice means one reply, no matter how many retries.