tryflowy.ai. The identity handoff fixes that: pass the visitor’s PostHog ids in the link, and Flowy continues the same journey. Once they sign up or sign in, everything they did before the click is attached to their account.
This only joins journeys within one PostHog project: it’s for Flowy-operated pages instrumented with the same project as Flowy itself. Ids from a different project don’t break anything: they just start a fresh anonymous visitor rather than continuing one.
The parameters
Put them in the hash fragment: a fragment never reaches server logs or the
Referer header:
?ph_distinct_id=…) are also accepted. When both carry a value, the fragment wins.
Decorating a link
get_distinct_id() returns the literal sentinel $posthog_cookieless; Flowy discards it on arrival.
What happens on arrival
- The parameters are read once and immediately removed from the address bar, so they never linger in a URL that could be copied or shared.
- They take effect only for a visitor who has accepted analytics cookies on Flowy. A visitor who accepts later and then signs in has the handed-off journey merged at that point instead.
- Invalid values are discarded: wrong characters, over-long ids, session ids that aren’t a fresh UUIDv7, and the
$posthog_cookielesssentinel.