Purpose Against social cognitive and social exchange theories, this research paper aims to investigate the significance and interaction between perceived knowledge, involvement, trust and brand community engagement in brand communities (BC). Design/methodology/approach BC participants (n = 503) completed a cross-sectional survey for this research. Analysis was performed using PLS-SEM via SmartPLS (v. 4.1.0.2) and the novel Necessary Condition Analysis (NCA). Findings An integrative KITE model with positive and significant relationships of key BC constructs was established. The perceived BC knowledge influenced involvement and engagement. Furthermore, the constructs of involvement and trust were discovered to have a positive and significant impact on engagement, with trust having a substantial effect on BC engagement. The indirect effects of the trust construct via the BC knowledge and BC involvement constructs were also significant. Originality/value This research advances the existing conceptual approaches by introducing knowledge as the key BC constructs. The study illustrates that members’ knowledge about a BC facilitates their involvement in the BCs. The vital role of trust is revealed in the KITE model, as it is significantly related to BC knowledge, BC involvement and BC engagement with at least medium to large effect sizes. Notably, the role of trust is enhanced as it is the only necessary must-have (instead of “should-have”) condition to achieve high levels of BC engagement. Furthermore, the KITE model provides insights for marketers to develop a valuable BC.