# How Score works

> Leyline Score v2. 100 × sum(weight × value) over observed factors only. Unobserved factors are omitted, not zeroed.

JSON: https://staging.leyline.ahensya.com/api/v1/score/algorithm

## Weights

- github_health: 0.18
- agent_use: 0.16
- human_notes: 0.14
- composability: 0.16
- checklist: 0.1
- evidence_quality: 0.14
- benchmark: 0.12

## Notes

- Score v2 is evidence-only. A factor without an observed signal is insufficient evidence, not a zero.
- Purging fabricated seed and intake metrics lowers and flattens Scores. That is intended.
- Humans and agents are first-class. Neither base can invent the other.
- Composability enters Score only when an observed signal exists. A rationale sentence is not a number.
- Checklist starters are MCP, API, and cost range. Those are declared claims on the record, not usage metrics.
- Benches enter only when Leyline or an external bench is observed with source, method, and observedAt.
- Intake must not write stars, installs, success, abandons, resolve wins, trust, or benches unless they were observed.