What problem does it solve? Building neural-mass models of brain activity requires choosing the right dynamical model, wiring structural connectivity with delays, adding stochastic drive, mapping latent activity to BOLD/EEG/MEG observables, and fitting parameters—each step with its own API pitfalls. This Skill guides an agent through the complete BrainMass workflow so simulations, network coupling, and parameter fitting follow the correct contracts. ## Core Features & Use Cases - Model discovery and simulation: Use brainmass.list_models() to select from phenomenological, physiological, seizure, decision, and oscillator models, then run them through the uniform Simulator with monitors, transients, and batched stochastic trials. - Delay-coupled whole-brain networks: Wrap an N-region model in brainmass.Network with structural connectivity, conduction delays, and diffusive, additive, sigmoidal, or Jansen-Rit coupling. - Observation models and fitting: Map neural activity to BOLD (HRF convolution or Balloon-Windkessel), EEG/MEG lead fields, then fit trainable Param values with gradient, Nevergrad, or SciPy backends via Fitter and reusable objectives (FC, FCD, RMSE). - Use Case: Fit a Hopf oscillator's bifurcation parameter to match the amplitude of an empirical signal, or build a connectome-based whole-brain network and compare simulated functional connectivity against measured data. ## Quick Start Ask the agent to simulate a Hopf neural-mass model with BrainMass, add Ornstein-Uhlenbeck noise, and run eight batched trials while monitoring the x state variable.