Rendered from docs/obligations/0092-how-a-probe-reaches-a-harvesting-tier-and-what-a-transcript.md in the Headwater corpus. Every document on this half of the site is typed by the taxonomy the descriptor names: corpus.json.

How a probe reaches a harvesting tier, and what a transcript costs to keep

Context

Q8 rules that cadence follows the purpose of the run, and it leaves three things open.

Obligation

How a probe reaches a harvesting tier, which has no tier to try it on. The retention policy for transcripts, whose size nobody has measured. Whether any adopter ever pays for a campaign.

Discharge

The third is a business-model question, and Q11 places it rather than answers it. The first two wait on a tier and on a measurement, and neither exists.

Discharge, 2026-09-20

All three threads are now answered, and this record closes. #165 shipped the route from a probe to a tier: two tiers exist in .headwater/probe.yml, and --tier selects one. #515 settled the retention policy for a probe transcript. Spec 15 states it: the transcript and the probes never expire, and nothing in that part sets the window in which a reader can still build the named grader. The third was already answered when this record was drafted, by the reference to Q11 two paragraphs above.

Neither #165 nor #515 was #87's to close. #87 asked a narrower question this record never named: whether a budget prices only a probe run, or every mechanism that reaches a model. HW-DR-0076 answers it. It rules that the coherence sweep sits outside the budget mechanism this record's route thread already described.