werkrevisor/docs/prs/2026-10-07-PR#43-cost-lower-bound.md

PR#43: the statistics show an unknown model cost as a lower bound

WARNING: This document describes only the change applied in this PR. It may already be outdated once the next PR is merged. Historic PR documentation is not maintained along with new PRs; treat it as a snapshot.

The Problem

When the model call of a review fails, e.g. after a timeout, PR-Agent reports no usage, so its cost is unknown. The list of recent reviews on the statistics page then shows the cost as ≈ 0.0001 USD + LLM unknown. The text in the cost column is no amount and widens the column.

Non-Goals

• No change of the sums: they keep the count of reviews with an unknown cost.

The Solution

• The cost column shows the known part as a lower bound, e.g. ≥ 0.0001 USD.
• A tooltip on the amount says that the cost of the model call is unknown.
• werkrevisor 0.21.3.

Prerequisite PRs

• PR#40: werkrevisor 0.21.1, a failed advising model leaves the verdict to Jev, merged.