Meta Conversions

Server-side Meta Conversions API integration. The tracking-meta app sends a Purchase event when an order is confirmed, so conversions are attributed even when the browser Pixel is blocked.

How it works

1. OnOrderConfirmed observes orders and, on the not confirmed → confirmed transition, schedules the reactor with the order number.
2. meta.purchase.create loads the order, builds the event, and POSTs it to https://graph.facebook.com/{apiVersion}/{pixelId}/events.

De-duplication

The server event's event_id is the order number, the same value the browser Pixel sends for its own Purchase. Meta collapses the two into a single conversion, so running both the Pixel and this app does not double-count.

Customer data & privacy

Customer parameters (em, ph, fn, ln, ct, zp, country, external_id) are normalized (lowercased and trimmed) and SHA-256 hashed to lowercase hex per Meta's spec before being sent. external_id is the order's customer number.

fbp, fbc, the client user-agent and the client IP are sent raw, as Meta expects. Any field that is missing is omitted rather than sent empty — that only affects Meta's event match quality, never whether the event is accepted.

Tracking ids

The identifiers come off the order under the shared cart: namespace, having been stamped on the cart by the storefront:

Meaning	Order field
Meta browser id (_fbp)	cart:tracking:fbp
Meta click id (_fbc)	cart:tracking:fbc
Client user-agent	cart:client:userAgent
Client IP	cart:client:ip
Storefront origin	cart:storefrontUrl

The user-agent, client IP and storefront origin are captured automatically when the cart is created; only fbp and fbc need storefront code. Without them the event still works off the hashed customer data, at lower match quality.

event_source_url is taken from cart:storefrontUrl, falling back to the channel registry's storefrontBaseUrl.

Conversion value

custom_data.value is reported excl. tax, but incl. shipping — the standard for Meta's Purchase event. For tax-inclusive orders the tax is stripped (orderTotal − orderTaxTotal); tax-exclusive totals are already net.

Per-item contents[].item_price stays at the catalog listing price, since those feed product matching rather than bidding optimization.

Different platforms, different values

The Google Analytics app excludes shipping from its conversion value and reports it separately, following GA4's own convention.

Settings

Setting	Secret	Description
enabled	no	Master switch. When off, the reactor does nothing.
pixelId	no	Meta Pixel / Dataset ID that receives the events.
accessToken	yes	Conversions API access token from Events Manager.
apiVersion	no	Graph API version, e.g. v19.0 (default).
testEventCode	no	Optional. Routes events to the Test Events view.

The app is inert until enabled is on and both pixelId and accessToken are set, so installing it has no effect until it is configured.

Verifying

Set testEventCode and place a test order, or schedule the reactor directly for a known order number. The event then appears under Events Manager → Test Events.

See Also

• Conversion Tracking — the app family and shared conventions
• Storefront Integration — capturing fbp and fbc
• Cart Dynamic Fields — how the ids reach the order