Dispatcher-email backfill.

The problem

The carrier-dispatcher email field is blank on most loads, so nothing automated can email the right person. The right address usually exists, buried in the rate confirmation's recipient line in the activity log.

How it works

• A read-only scan of 396 loads, about 1,000 API calls with zero errors, proved the shape first: 69 percent auto-fillable, 26 percent a real human decision, 5 percent no rate confirmation yet.
• The fill writes only when the field is blank and the rate confirmation went to exactly one external address.
• Never-overwrite is enforced twice: a free pre-filter on the snapshot, then a fresh re-read immediately before the write. The TMS has no compare-and-swap, so the write is a single attempt, no retry, bounding the honest residual race to seconds.
• Shipped dark behind a default-off flag. The first live cycle earns the go-ahead, not the other way around.

// write only when the field is blank and the answer is unambiguous; re-read immediately before the write

The result

A pipeline that can fill about 7 in 10 blank dispatcher emails with zero overwrites, waiting behind a flag until the owner says go. Also the enabler for the ETA bot's fresh-thread fallback.