Changelog

Core principle

Keep consumer-visible notes complete and grounded in verified changes while preserving curated wording and released history.

Procedure

1. Establish the requested scope, repository conventions, changelog path and Git state. Choose Unreleased maintenance or specified-release notes; keep reviews read-only. If the user limits work to supplied state, run no discovery commands and mark unsupplied facts unknown. This skill applies across languages and publishing systems; it requires no Kotlin plugin, credentials, API snapshots or release approval. If no changelog exists and creation was not explicitly requested, report that it was skipped and finish. For explicitly requested creation, resolve its format and history scope first.
2. Establish the comparison range from repository tag conventions and ancestry, or supplied evidence. For Unreleased maintenance, compare against the latest applicable release, preserving the repository's incremental prerelease baseline. For specified-release notes, use the supplied target version; resolve a missing or ambiguous target before editing. For a specified prerelease, retain the repository's incremental baseline from the preceding applicable release. Keep an active prerelease cycle expanded. A final release uses the previous stable release as the baseline for the whole cycle, not only the latest RC delta; a first stable release covers history from the start. Resolve ambiguous tags rather than choosing the lexically highest one. Unreleased maintenance needs no next development version.
3. Compare existing notes with complete in-scope history, diffs and relevant issue/PR evidence. Preserve accurate curated wording; add missing consumer-visible changes, correct inaccuracies and omit internal-only changes. Attach each citation and credit only to an entry describing that change; give an uncovered change its own entry. Include relevant breaking changes and migration guidance. Resolve uncertain coverage or report the specific gap rather than inventing a claim or declaring completeness. For a final stable release, read stable-release notes completely before editing and follow its coverage and history procedure.
4. Verify links and attribution. For each PR-supported change, link its number directly to the canonical pull URL, for example [#123](https://github.com/OWNER/REPO/pull/123). Link matching issues where appropriate using explicit Markdown URLs; bare numbers are insufficient. For a verified non-maintainer PR author, include their verified name or username linked to their GitHub profile. Establish authorship from the PR and maintainer status from repository evidence. Supplied facts count as evidence; query a provider only when facts are missing and access is authorized. Report unverifiable URLs, authorship or maintainer status, and missing profile URLs for verified non-maintainers. Maintainers need no profile credit. Preserve accurate curated text apart from requested links and credit; never invent identities or classifications.
5. Apply only authorized changelog edits. Keep Unreleased maintenance under its existing heading. For specified-release notes, preserve repository heading, date and anchor conventions; finalize the heading only when requested. When called by release-kotlin-library, leave heading finalization to its release helper unless the caller explicitly requests changelog-only finalization. Leave Git mutations (including pulls and commits), version files, snapshots and publication to the caller. A reviewable changelog does not authorize those actions.
6. Inspect the actual diff against the reviewed changes, verify citation placement and preserved released history, and run git diff --check when command execution is permitted. Use repository documentation validation when required by its instructions or the changed formatting; report any unavailable validation. A heading check alone cannot establish semantic completeness.

Finish gate

Show the actual notes or a directly reviewable diff, the comparison baseline and reviewed scope, validation performed and unresolved evidence or coverage gaps. For a read-only review, show findings or proposed notes without claiming edits. For a missing changelog, report the skip without claiming reconciliation. For a final release, verify every surviving coverage-ledger row appears in the stable summary and the original prerelease history remains intact before claiming the notes complete. Hand these results to the calling release workflow when applicable; that caller owns remaining release gates and approval.