Methods and systems for delivering data contents among peer nodes in a decentralized data delivery network are disclosed. The network comprises peer-to-peer (P2P) connections implemented on top of a content delivery network (CDN) having CDN servers that provide fragments of data files to network nodes. Such a hybrid network comprises viewer peer nodes, edge cacher peer nodes, tracker servers, and optionally a payment server. A viewer peer node sends a peer list request to a tracker server for peer discovery in accessing a data file, and in response the tracker server provides a peer list by selecting active cacher nodes based on network locations and/or geolocations of neighboring nodes, and a content data type of the desired data file. A software development kit (SDK) is provided for integration into existing third-party content viewers so that the functionality of the hybrid network is available to users via existing content viewers.