Review credits explained
How ADO Pilot converts a pull request diff into review credits, and what code is excluded from the count.
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A review credit (RC) is the unit ADO Pilot bills in. One RC covers roughly 500 lines of changed code, and every review costs at least 1 RC. This page explains the formula, walks through worked examples, and lists the code that does not count toward your bill.
What is a review credit?
A review credit (RC) is the unit ADO Pilot bills in. Every PR review costs at least one RC, and longer diffs cost more in proportion.
The formula:
RC = ceil(billing_diff_lines / 500)
Where billing_diff_lines is the sum of additions and deletions in the PR diff, after exclusions are applied (binary files, paths matching the org's exclusion list, and per-line normalization for very long lines).
A 650-line diff therefore costs ceil(650 / 500) = 2 RCs. A 90-line diff costs 1 RC (the minimum). An empty diff — for example, when a PR is updated with a commit that touches only excluded files — costs 0 RCs and consumes none of your monthly allocation.
The "billing diff" is the diff Azure DevOps shows in the PR view: additions plus deletions, after binary files and excluded paths are stripped. ADO Pilot uses the same numbers the ADO UI shows, so a quick glance at the PR's "Files" tab tells you the upper bound on the RC cost before you submit.
How many RCs does a PR cost?
| PR diff size (billing lines) | RC cost |
|---|---|
| 1 to 500 | 1 |
| 501 to 1,000 | 2 |
| 1,001 to 1,500 | 3 |
| 1,501 to 2,000 | 4 |
| 2,001 to 2,500 | 5 |
Worked example. A PR adds 410 lines and deletes 240 lines across non-excluded files. Billing diff is 410 + 240 = 650 lines. RC cost is ceil(650 / 500) = 2 RCs. Re-running the review on the same commit does not charge again — only new commits trigger a new review.
What code does not count?
ADO Pilot excludes generated, vendored, and binary content from the billing diff so you are not charged to review files no human edits by hand.
- Binary files. Images, archives, and other non-text blobs contribute 0 lines.
- Default exclusion patterns. Lockfiles such as
package-lock.json, minified bundles such as*.min.js, and other generated artifacts are excluded by default. See the default exclusion list. - Custom exclusions. Patterns you add at the org, project, or repo level are also stripped before the count.
- Long-line normalization. A line longer than 200 characters counts as multiple billing lines. This is a safety guardrail that prevents a single minified file from costing 1 RC when it should cost dozens.
Empty diffs and abandoned reviews
If a PR update touches only excluded files, the billing diff is empty and the review costs 0 RCs.
If you push a new commit while a review is still running, ADO Pilot abandons the in-flight review and starts over on the new commit. The abandoned run is not billed.