eligo — I choose (Latin)

Best-of-N image generation that selects the best candidate by a measurable reward, rather than returning a single one-shot result.

eligo is Latin for "I pick out / I choose" — the root of elect and elite. Choosing is the tool's one job. Where revelo reveals and viser sees, eligo chooses: given a prompt, it generates n candidate images through a [Backend], scores each against the prompt with a [Scorer] (the reward), and returns the highest-scoring one. An optional bounded re-roll replaces the single worst candidate once. That generate → score → select loop is the smallest honest agentic pattern: a numeric reward drives a decision.

Scope (deliberately bounded)

eligo is a selection library, not a model zoo or an editor. It owns the loop and the contracts ([Backend], [Scorer]); concrete model inference (a Stable Diffusion backend, and CLIP scoring via ONNX Runtime) are pluggable implementations behind those traits. The default build ships a deterministic mock backend/scorer so the loop is testable without model weights.

use eligo::{best_of_n, GenerateConfig};
use eligo::mock::{MockBackend, MockScorer};

let backend = MockBackend::default();
let scorer = MockScorer;
let cfg = GenerateConfig::new("a red bicycle").with_candidates(4);
let selection = best_of_n(&backend, &scorer, &cfg).unwrap();
assert_eq!(selection.all.len(), 4);
// The chosen candidate is the highest-scoring one.
let top = selection.all.iter().map(|c| c.score).fold(f32::MIN, f32::max);
assert!((selection.best().score - top).abs() < f32::EPSILON);