event-contract-matrixlisted

# Event Contract Matrix A discipline for documenting **who produces and who consumes each event** in an event-driven or pub/sub system. It keeps the event contracts a single source of truth, so a change to a producer or consumer is visible against the whole graph instead of being discovered per call site. **The defining constraint:** the matrix records the **many-to-many** relationship — each event lists its dispatch sites and its listeners — and explicitly notes sites that **deliberately bypass** the normal emit path. An event contract is not just "this event exists"; it is who can hear it. ## What the matrix records - **One row (or entry) per event**, listing: - the **producer(s)** that dispatch it — including any dispatch site that deliberately bypasses the standard emit path (e.g. containment-driven dispatch), so those are visible rather than a hidden surprise; - the **listener(s)** that receive it. - **The relationship shape**: many-to-many, so the matrix is a table of event → producers and event → listeners, not one large implicit graph. A dense many-to-many relation is best presented as a table rather than a sprawling graph — one event per row, producers and listeners as columns. ## Keeping it a single source of truth - **Update the matrix in the same change that changes an event contract** — a new event, a new producer, a new listener, or a new bypass site. Do not let the matrix drift from the code. - **Treat the matrix as the contract's home.** Where a con