is the FPID required for first party tracking

Technically: no.

Strategically: maybe.

It is not required essentially; you can do Target + Analytics + Web SDK with just:

CNAME first‑party collection, and
Standard Adobe IDs (ECID, Visitor id, AAUID etc.)

CNAME is enough to:
Get calls through ad blockers in many cases

Make cookies first‑party (but short‑lived on Safari)

When FPID becomes worth it

You are on or moving to AEP Web SDK / Edge and want:

More stable device identity across Safari / ITP beyond 7 days

Less inflation of unique visitors (because ECID keeps changing when cookies die)

More stable profiles and segments in AEP / CJA / Target over time

Hope that helps!

Thank you! 

Sarthak Bhatt | Senior Product Consultant | Customer Experience | Adobe  

Hi ​@Michael_Soprano 

these are two things.

FPID

• a FPID service is running on your own web servers
• returns a true first-party cookie which lifetime cannot be limited by any browser

Hence you do not need a CNAME domain for the FPID service to work.

CNAME 

• a subdomain through which you send your Edge network requests which in their response Adobe returns a presumably first-party cookie (kndctr cookies)
• without the CNAME, the lifetime is heavily restricted since it is a third-party cookie
• NOTE:
  • with the CNAME, most browsers accept it as first-party cookie
  • however some browsers notice that the receiving IP behind your CNAME is Adobe and not your own website, and still treat it as third party cookie with limited lifetime  (e.g., through Safari’s ITP).

Best practice should always be aiming for a FPID cookie which you can then also make use of in other marketing pixels and server-side forwarding (CAPI) for better user identification.

Note though, that this user identification underlies the usual cookie consent limitations i.e., your FPID cookie must be categorized as for instance “Analytics or Tracking” cookie and the use is restricted to the given consent.