swathikchhuggingface/assay-playground

Assay playground

A synthetic warehouse with seven planted defects, and six metric definitions describing it. Every control edits a definition, never the data.

The checks are generated from the contract, so changing what a metric claims about itself changes which checks exist at all. Flip active_users to additive and a 1477% discrepancy appears from a single label — nothing is wrong with the data or the SQL.

Then press Restate a closed month to reproduce the finding almost nothing else reports: a month everyone considered finished, silently rewritten.

Assay is phase P0 — an invariant engine over metric definitions a team already has. No language model, no query interface, no dashboard.