Abstract
This is about finitary constructions of structures/models synthesised from given local pieces with a specification of their desired pairwise overlap structure. The core construction uses groupoids with specially designed acyclicity features as a generic backbone for the realisation of such amalgamation patters. This leads to generic and symmetry preserving extensions of local to global coherence (in the spirit of path-independence requirements towards global relational consistency) with applications to hypergraph coverings, modal and guarded logics, and extensions of local to global symmetries in finite models.