End-user flexibility is an essential resource for decarbonized energy systems, and can be exploited via distributed flexibility markets. To participate, end-users must weigh potential revenues against their primary objectives, subject to their operational constraints. This work presents a technology-neutral framework to simultaneously determine the optimal operation, flexibility bids and prices by extending original operation planning problems into two-stage stochastic ones. Recovery constraints are introduced to exclude potentially adverse bids. As case studies, diverse residential end-users, who minimize their cost and additionally place flexibility bids, are analyzed. The results reveal complex time-varying and system-specific dynamics of bid volumes and prices. For example, heating systems receiving flat electricity rates can effortlessly bid flexibility from forcing early heat generation, namely, positive flexibility for combined heat and power units and negative flexibility for heat pumps. However, under time-varying rates, bid patterns change and become synchronized, which can cause scarcity in markets with homogeneous participants. With this framework, end-users can assess technical and economic potentials, plan their operations and market participation. As operation planning also reckons with the expected flexibility demand of the system, bids in time of need are likely higher. Lastly, detailed potential assessments also aid operators in designing flexibility portfolios or markets. • Stochastic programming integrates uncertain flexibility calls in operation planning. • Bids respect operation constraints and objectives via the direct integration. • The introduced buffer prevents system-adverse recovery after the provision. • Optimal flexibility bids and related prices are time- and system-dependent. • The synchronization effect of time-varying electricity rates can cause bid scarcity. [ABSTRACT FROM AUTHOR]