Optimizers

Six optimizers are available, each suited to a different problem shape. See Choosing an optimizer for how to pick one, or Understanding optimization for how the optimization loop works.

Parameters by optimizer

The parameter set below describes what you pass in the platform’s optimization request when you create a run, not arguments to the class constructor; see Run an optimization for one optimizer’s parameters going into a request end to end. Optimization Objective (task_description) is present on every optimizer’s form, though nothing is prefilled into it.

Optimizer	Class	Use it when	Parameters (label / code key / default)
Random Search	RandomSearchOptimizer	First look at a prompt’s headroom	Number Variations (num_variations), 3
Bayesian Search	BayesianSearchOptimizer	Tuning few-shot examples on solid instructions	Min examples (min_examples), 2 Max examples (max_examples), 4 No.of trials (n_trials), 5
ProTeGi	ProTeGi	Parallel candidate fixes from failing examples	Beam size (beam_size), 4 Number of gradients (num_gradients), 4 Errors per gradient (errors_per_gradient), 4 Prompts per gradient (prompts_per_gradient), 1 Number of Rounds (num_rounds), 3
Meta-Prompt	MetaPromptOptimizer	One prompt refined over rounds, not parallel candidates	Optimization Objective (task_description) Number of Rounds (num_rounds), 4
PromptWizard	PromptWizardOptimizer	Wording itself, not one instruction, is the ceiling	Mutated Rounds (mutate_rounds), 3 Refined Iterations (refine_iterations), 2 Beam size (beam_size), 2
GEPA	GEPAOptimizer	Widest search of the six, 40 metric calls prefilled	Max Metric Calls (max_metric_calls), 40

Every parameter listed above must be passed on the optimization request. The values shown are what the form prefills when you pick that optimizer, and you can change any of them before you start the run. A request missing any listed parameter, or carrying a parameter that isn’t listed for that optimizer and isn’t task_description, is rejected before the run starts; see Common errors and fixes for the exact error.

task_description is the one parameter allowed outside a row’s own list: it can additionally be passed on any optimizer’s request, even where its row above doesn’t list it for that optimizer, and Meta-Prompt is the one optimizer that requires it as part of its own parameter set.

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