Facebook Conversions API Diagnostic Guide

if you're experiencing issues with your facebook conversions api (capi) destination, this guide will walk you through common problems and how to resolve them each flow below addresses a specific issue with step by step troubleshooting instructions events not appearing in events manager symptoms expected server events (like purchase ) are not visible in meta events manager you’ve recently configured capi but see no activity how to troubleshoot confirm the capi destination is created in chord cdp and has an active connection with a back end source verify the pixel id and access token values for the destination correspond with the values listed in your meta business/events manager account go to meta’s test events tool and trigger a known action look for http 200 responses and verify no errors like 401 unauthorized → invalid token or app config 400 bad request → missing or incomplete payload retry with a minimal payload (just event name , event time , and user data ) to isolate the issue duplicate events or overcounting symptoms conversion counts appear inflated in meta ads manager same action appears twice under “received events ” how to troubleshoot check whether pixel and capi are both firing the same event confirm the event id field is included in both and matches exactly visit meta events manager → diagnostics tab to see any deduplication warnings use the test events tool and look for a single deduplicated instance of the event low match rate or inaccurate attribution symptoms meta ads manager reports poor attribution for key campaigns low conversion match rates despite capi being enabled how to troubleshoot confirm that user data includes identifiers like fbc / fbp array of hashed external ids including anonymous id and user id hashed email ( em ) hashed phone ( ph ) hashed zip code ( zp ) hashed country ( ct ) hashed first name ( fn ) hashed last name ( ln ) turn on advanced matching in the meta pixel settings optionally, a/b test campaigns with vs without capi enabled to evaluate impact best practices recap recommendation why it helps use capi + pixel covers blind spots, improves accuracy use matching event id prevents overcounting include full user data boosts attribution match rates monitor diagnostics tab flags misconfigurations test frequently verifies end to end setup