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OneView automatically prevents duplicate events from being processed using idempotency keys. No configuration required.

What is Deduplication?

Deduplication prevents the same event from being processed multiple times, ensuring each conversion is counted exactly once in your workspace and sent to advertising platforms only once.
Understanding deduplication vs. merit-based routing:
  • Deduplication: Prevents the same event from being processed multiple times (e.g., page refresh fires the same event twice)
  • Merit-based routing: Prevents the same conversion from being sent to multiple platforms (e.g., both Google and Meta claim the same purchase)
Both work together to ensure accurate conversion tracking.

How Deduplication works

OneView uses idempotency keys to identify and block duplicate events. When you send an event with the same idempotency key within the deduplication window (14 months), OneView processes it only once.
ScenarioFirst EventDuplicate EventResult
Same idempotency keyProcessedBlockedEvent counted once
Different idempotency keyProcessedProcessedBoth events counted
Key outside windowProcessed (expired)ProcessedBoth events counted
Idempotency keys are valid for 14 months. After this period, the same key can be reused for a new event.

When duplicates occur

Event duplication happens when the same user action triggers multiple tracking calls:
CauseExampleImpact
Page refreshesUser refreshes thank-you pageSame purchase event sent twice
Back-button navigationUser navigates back, then forwardEvent fires again
Multiple implementationsBoth GTM Web and backend send eventDuplicate tracking calls
Single-page appsRoute changes trigger multiple timesSame event fired multiple times
Without deduplication, a single purchase might be counted multiple times, inflating your conversion numbers and causing platforms to optimize on incorrect data.

Idempotency keys

An idempotency key is a unique identifier that ensures the same request produces the same result, preventing duplicate processing.
Best practices for idempotency keys:Use a combination of identifiers that uniquely identify the event:
  • E-commerce: user_id + order_id + event_type
  • Lead forms: user_id + form_id + timestamp
  • Page views: client_id + page_url + timestamp
The key should be deterministic—the same event should always generate the same key.

Deduplication window

OneView maintains idempotency keys for 14 months to prevent duplicates across extended customer journeys.
TimeframeBehavior
Within 14 monthsSame key blocks duplicate events
After 14 monthsKey expires, can be reused
The 14-month window covers most customer journeys, including long B2B sales cycles and repeat purchases. If you need a longer window, contact support.

Common questions

Include an Idempotency-Key header or field with each event request using a unique identifier. For example:
  • E-commerce: user_id + order_id + event_type
  • Lead forms: user_id + form_id + timestamp
  • Page views: client_id + page_url + timestamp
OneView automatically uses this key to prevent duplicate processing.
OneView generates a deterministic idempotency key based on your event payload. However, explicitly providing an idempotency key gives you more control and ensures consistent deduplication across different implementations.
Deduplication and merit-based routing work together:
  1. Deduplication ensures the same event isn’t processed multiple times in OneView
  2. Merit-based routing ensures the conversion is sent only to the platform that wins attribution
Both are automatic and require no configuration.
Everything happens automatically in your workspace, and you will only see the final result in your reports.

Next steps