Meta Conversions API.

Mirrors browser-pixel conversions from the server so they still land when the visitor blocks the pixel, and deduplicates against the browser fbq('track', …, {eventID: id}) through a shared event_id.

Credentials

%{pixel_id: "123…", access_token: "EAA…", test_event_code: "TEST1234"}

test_event_code shows the event in Events Manager's test tool without it counting — the only way to verify the payload shape without spending real attribution on a guess.

fbc

Meta matches a server conversion to the ad that paid for it through fbc, built from the fbclid captured at the click:

fb.1.<unix_ms>.<fbclid>

Pixelex.Attribution captures the fbclid; fbc/2 builds the string. Pass the raw click id as user_data.fbclid and this does the rest. Without it a conversion is attributed to nothing, which is the same as not sending it.