Design and Analysis Tools for Target Trial Emulation // Design and analysis tools for target trial emulation using longitudinal observational data. Functions are provided for checking person-period data, expanding longitudinal data into sequentially nested trials, estimating inverse probability weights for intention-to-treat and per-protocol analyses, and assessing weight distributions and covariate balance. Additional functions fit weighted pooled discrete-time outcome models, obtain standardized risks and treatment contrasts, and estimate weighted Kaplan-Meier and Aalen-Johansen curves. Two worked examples based on fully synthetic data illustrate an active-comparator new-user study comparing sodium-glucose cotransporter 2 inhibitors with dipeptidyl peptidase-4 inhibitors and an analysis of sequentially nested trials comparing angiotensin receptor blocker and calcium channel blocker strategies.