Select

select chooses one or more valid parent generations from the durable archive. It is required and runs before a child checkout is created.

Contract

Implementation interface:

class SelectOperator:
    def pick(self, archive, ctx) -> SelectResult: ...

The result contains parent generation IDs. A selector must use valid archive parents; it must not invent a generation or select an ineligible row.

Variants

Variant	Selection policy
greedy	highest-scoring valid parent
newest	newest valid parent
random	uniform random valid parent
score_weighted	random parent weighted by nonnegative score
ahe_latest	newest structurally valid AHE generation, independent of score
pareto	GEPA selection from per-task Pareto frontiers
score_child_prop	HyperAgents score-proportional selection with a child-count penalty

Configuration

operators:
  select:
    variant: greedy
    timeout_s: 600

Stochastic selectors use the experiment/operator seed so a frozen workspace can reproduce their decision process. Method-specific variants may write selection diagnostics; for example, pareto writes:

runs/gen-N/select/pareto.json

Choosing a variant

• Use greedy for a simple hill-climbing baseline.
• Use ahe_latest when artifact-valid iteration matters more than current aggregate score.
• Use pareto when per-task coverage defines the population.
• Use score_child_prop when high-scoring parents should be favored without repeatedly expanding the same lineage.