PR title rewriting

Off by default. When enabled, Rusty Bot rewrites the PR title into Conventional Commits format (type(scope)?!?: subject) before the review runs — useful when squash-merging into a repo that derives changelog or release notes from PR titles.

Enabling it

RUSTY_RENAME_TITLE_TO_CONVENTIONAL=true

Or enable per-repo via the dashboard for the self-hosted GitHub App.

How it works

1. Before the review starts, the bot inspects the current PR title
2. If the title already matches the Conventional Commits regex (type(scope)?!?: subject), it is left untouched
3. Otherwise, a dedicated agent picks a type (feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert), an optional scope, a cleaned subject line, and a breaking-change flag based on the diff and metadata
4. The new title is written back to the PR via the platform API and used for the rest of the run

Length handling

PR titles are capped at 256 characters (the tighter of GitHub’s 256 and Azure DevOps’ 400 limits). When the generated title would exceed that, the bot:

1. Drops the scope (feat(longscope): subject → feat: subject)
2. If still too long, truncates the subject and appends an ellipsis, preserving the type prefix and any breaking-change marker

Tuning

Variable	Description
RUSTY_TITLE_TEMPERATURE	Temperature override for the title-rename agent (falls back to RUSTY_LLM_TEMPERATURE)

Safety

Already-conventional titles are never modified. The agent reuses wording from the original title and only adjusts the prefix, scope, and casing. The rewrite is wrapped in a try/catch — if the LLM call fails, the schema validation fails, or the formatted title fails the post-format sanity check, the failure is logged and the review continues with the original title.