Meta Conversions API

Credentials

business.facebook.com → Events Manager → select your data set (pixel).
Settings → section Conversions API → Set up manually → Generate access token.
Note the pixel id (data set id) shown in the same place.

PUT /v1/projects/{project}/destinations/meta
{
  "enabled": true,
  "mode": "test",
  "transport": "direct",
  "settings": { "pixelId": "1234567890123456", "apiVersion": "v26.0", "testEventCode": "TEST12345" },
  "secrets": { "accessToken": "EAAB…" }
}

With "transport": "composio" and an adConnectionId, events go through Composio's METAADS_SEND_CONVERSION_EVENTS using the Meta ad connection – no separate token is stored. The connection's token must have access to the pixel.

What is sent

POST https://graph.facebook.com/{apiVersion}/{pixelId}/events with one event per conversion:

Field	Value
`event_name`	the definition's Meta `eventName`
`event_time`	conversion time (Unix seconds)
`event_id`	the conversion's event id (deduplication with the browser pixel)
`action_source`	`chat` for `whatsapp_manual`; `website` for quiz/booking/event/goal/lead conversions with a user agent; otherwise `system_generated`
`event_source_url`	the page of the conversion (only with `action_source: website`)
`user_data.em`, `ph`, `fn`, `ln`, `external_id`, `country`	SHA-256 hashes, normalized per Meta's rules
`user_data.client_ip_address`, `client_user_agent`	request context, when your server passed it
`user_data.fbc`	the `_fbc` cookie, or built from the session's `fbclid` (`fb.1.<ms>.<fbclid>`)
`user_data.fbp`	the `_fbp` cookie (only after consent, or passed by your server)
`custom_data.value`, `currency`	from the conversion or definition, when the value is above 0

An event needs at least one match key (em, ph, external_id, fbc, fbp or IP); otherwise the status is skipped ("no customer identifiers"). Meta accepts events up to 7 days old; older conversions are skipped (3x keeps one hour of margin).

Deduplication with the browser pixel

If you also fire the pixel in the browser, pass the same event name and the same id (eventID in fbq('track', 'Lead', {}, { eventID })) as the conversion's eventId. Meta then counts one conversion. In the browser, x3.conversion(definition, { eventId }) takes your id (or resolves with the generated one); from your server pass eventId to conversions.create.

Testing

Events Manager → Test events → copy the test code into settings.testEventCode.
Set the destination mode to test (or live with the test code – events then still land in Test events).
POST /v1/projects/{project}/destinations/meta/test or trigger a real conversion.
Check that the event appears as Server and – when the pixel fired – as deduplicated.
Remove the test code and set mode: "live".

Typical errors

Error	Meaning
`190 Invalid OAuth access token`	token revoked or expired – generate a new one
`100 Invalid parameter` with `event_time`	conversion older than 7 days
`2804050 … test_event_code`	the test code no longer exists – remove it

#Meta Conversions API

#Credentials

#What is sent

#Deduplication with the browser pixel