Conversions API (CAPI)

Meta recommends using CAPI alongside the pixel rather than treating it as a complete replacement. The two methods complement one another’s missing data. If the same event_id is not supplied for the corresponding browser and server event, one purchase can be counted twice, making deduplication a common implementation pitfall. Ecommerce platforms such as Shopify and Cafe24 offer integrations that can simplify deployment without extensive development resources.

Business applications and impact#

Combining CAPI with the pixel can reduce conversion data loss from platform tracking restrictions and cookie blocking, supporting bidding performance and ROAS.

Implementation guidance and considerations#

Use matching event_id values for the same browser and server event and implement deduplication so that a single conversion is not counted twice.

Code example#

curl -X POST \
  "https://graph.facebook.com/v19.0/{PIXEL_ID}/events" \
  -d 'data=[{
    "event_name": "Purchase",
    "event_time": 1716800000,
    "event_id": "order_8841",
    "user_data": {"em": ["<hashed_email>"]},
    "custom_data": {"currency": "KRW", "value": 89000}
  }]' \
  -d 'access_token={ACCESS_TOKEN}'