PlanX is the flagship of the PlanX ecosystem: a self-contained urban analytics studio for city planners and researchers. It embeds real implementations of the methods urban analysts usually need separate tools for - space syntax segment angular analysis (integration, choice, NACH/NAIN), the full centrality family (degree, closeness, straightness, eigenvector, betweenness), urban morphology (building form metrics, morphological tessellation, Spacematrix GSI/FSI/OSR, street orientation entropy), network accessibility (OD cost matrix, service-area isochrones, nearest-facility allocation, multi-amenity 15-minute-city scores with population-weighted summaries), accessibility-equity analysis (population-weighted Gini, a Theil index split into between- and within-group inequality, P90/P10 ratio and access-poverty share, plus a Lorenz/concentration curve export and the Atkinson index at a chosen inequality-aversion - the spatial-justice view), microclimate screening (date-and-time shadow casting with an embedded NOAA solar-position model, whole-day sun-hours maps, clear-sky daily solar irradiation combining shadow-aware beam with SVF-weighted diffuse light, annual solar potential summing twelve representative average-day sweeps into a yearly kWh/m2 map with an optional 12-band monthly raster, sky view factor, frontal area index, and a vector heat-island risk grid built from buildings, green and water layers), plan standards QA (land-use balance against configurable per-capita standards, facility adequacy combining capacity with network distance, dasymetric density grids), location-allocation optimization (greedy maximal coverage and Teitz-Bart p-median on network distances, with candidate-site screening and support for existing facilities, plus a capacity-respecting allocation that sends demand to the nearest facility with free capacity and spills to the next when it is full, and a multi-objective land-use allocation optimizer that assigns parcels to land uses to maximise total suitability while meeting a target area for each use, with optional compactness and adjacency objectives that shape contiguous, compatible zones, and a land-use Pareto front that runs the allocation across a sweep of compactness weights and reports the non-dominated suitability-versus-compactness trade-off with its knee, instead of committing to one weighted run), and a Plan Dashboard with live score cards plus a one-click single-file HTML Plan Performance Report (inline SVG charts, balance bars and score maps - shareable with stakeholders). Everything is computed inside the plugin with NumPy (SciPy used automatically when available, identical pure-Python fallback otherwise): no QNEAT3, no GRASS dependency, no UMEP, no servers, no pip installs. All tools are Processing algorithms - model-designer and batch friendly - and every tool carries its own icon in the toolbox and the PlanX Studio dock. Developed with feedback from educational workflows at Dokuz Eylul University, Department of City and Regional Planning.