API reference¶ Problem definition Problem Datafits Penalties Solvers Solver sklearn adapters celer adapters Wrapping an arbitrary callable Criteria Criterion CriterionResult HeldOutMSE HeldOutLogistic CrossVal Sure Hypergradient implicit_forward() Outer-search loops grad_search() hoag_search() Result and state dataclasses SolverResult IterationRecord SearchState SearchResult Type aliases Scalar Array Hyperparam DesignMatrix IndexArray sklearn-compatible wrappers LassoHO ElasticNetHO LogisticRegressionHO The four extension surfaces are documented separately in Protocols & extension points.