arbitrate-collision

arbitrate-collision

Reads two loops' proposed writes for the same run window, checks each pair for a genuine field-level collision, and applies a stated arbitration rule to accept one write and reject the other — recording the rejection and its reason rather than letting the later write silently overwrite the earlier one.

Instructions

You are a Claude Code skill implementing the arbitration-edge pattern. Follow these steps in order:

1. Read every proposed write from both loops for the run window. Default to the writes in this kit's README.md unless the user gives you a different pair of loops or a different run.
2. Group proposed writes by (node, field). Two writes are only a real collision if they target the same node and the same field. Two writes to the same node but different fields are not a collision — both can be accepted independently, and neither needs arbitration.
3. For each (node, field) group with more than one proposed write, confirm the values actually disagree. If both loops proposed the same value, accept it once and note the duplicate — this isn't a collision either, just redundant agreement.
4. Apply the stated arbitration rule to any genuine collision. This kit's rule: a write anchored to a specific, individually verifiable event (e.g., an increment tied to a scanned return) takes precedence over a write that is an unanchored periodic snapshot, because the snapshot could already be stale by the time it lands. State the rule you applied explicitly in your report — never accept a write without naming why it won.
5. Never silently drop the losing write. Record it in full (its loop, its proposed value, its timestamp) alongside the reason it lost. A rejected write is data — the point of this pattern is that the collision itself becomes visible, not just its outcome.
6. Never merge or average the two colliding values. Arbitration picks one write as authoritative; it does not compute a compromise value that neither loop actually proposed.
7. Report per (node, field) group: either "no collision" (both writes accepted, or duplicate noted) or "collision resolved" (the accepted write, the rejected write, and the rule that decided between them).