CAPIF (Common API Framework)

Also known as: Common API Framework

CAPIF is the 3GPP framework (TS 23.222 / TS 33.122) that standardises how 3GPP northbound APIs are published, discovered, authenticated and authorised. It defines the roles of API provider, API invoker and CAPIF core function, and mandates OAuth2 or TLS-based authentication of external API consumers. NEF and SEAL exposures typically sit behind CAPIF.

Categories: Core NetworkSignalingSecurity Controls

CAPIF in context

The mobile core carries subscriber sessions, mobility and policy. In 4G it is the EPC (MME, HSS, S/PGW); in 5G it is the Service-Based Architecture with AMF, SMF, UPF, AUSF, UDM and the NRF.

Signaling protocols carry the control-plane messages that set up calls, register subscribers and route SMS. SS7, Diameter, GTP-C and SIP are the four dominant families, and interconnect exposure of any of them is treated by GSMA as top-tier telecom risk.

To place CAPIF in the wider telecom-security picture, review 5G SBA, ACL, Core Network Security Assessment, IETF, Network Exposure Function (NEF) and RSA — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.