Increment the project version and consolidate the agent session changelog into a formal release entry.

Argument

$ARGUMENTS must be one of: patch | minor | major Default to patch if no argument is provided.

Step 1 — Detect current version

Search for the version string in this priority order:

1. pyproject.toml → [project] version = "..." or [tool.poetry] version = "..."
2. setup.cfg → version = ...
3. setup.py → version="..."
4. src/<package>/__init__.py or <package>/__init__.py → __version__ = "..."

Report the file found and current version before proceeding.

Step 2 — Compute new version

Apply SemVer rules to the detected version:

• patch: increment Z in X.Y.Z
• minor: increment Y, reset Z to 0
• major: increment X, reset Y and Z to 0

Step 3 — Harvest and categorise session entries

Read .claude/AGENT-CHANGELOG.md. For each new session entry, which is more recent than the current version, summarise the major changes and classify according to the keep a change log headings:

markdown
1## Version [<X.Y.Z>] - <YYYY-MM-DD>
2### Added
3  new features, scripts, models, datasets, analysis pipelines
4### Changed
5  modifications to existing behaviour or interfaces
6### Deprecated
7  functionality flagged for future removal
8### Removed
9  deleted files, functions, or data
10### Fixed
11  bug fixes, data corrections, broken tests
12### Security

If an object changes multiple times, or is created and removed within the new session entries DO NOT record these into the CHANGELOG. CHANGELOG version entry should reflect the current state of the package at the time the version is incremented.

AGENT-CHANGELOG.md = a full record of all changes iterations and tests made during development CHANGELOG.md = a record of the major changes which remain at the time of version increment.

If ambiguous, default to Changed. Only include headings that have entries.

Step 4 — Write the root CHANGELOG.md release block

Prepend a new version block to CHANGELOG.md in the project root (create if absent).

Step 5 — Lint the changelog

Run markdownlint --fix CHANGELOG.md to auto-fix any formatting issues.

Step 6 — Update the version in source

Write the new version string back to the exact file and line detected in Step 1.

Step 7 — Archive and reset the agent session log

1. Copy .claude/AGENT-CHANGELOG.md → .claude/archive/sessions-to-vX.Y.Z.md
2. Reset .claude/AGENT-CHANGELOG.md to:

markdown
1# Agent Session Log
2
3Run `/version-increment` to consolidate into the project CHANGELOG.md.
4
5---

Do not delete individual files in .claude/sessions/ — they are the permanent record.

Step 8 — Print release summary

Version bumped: X.Y.Z → A.B.C  (patch|minor|major)
Version file:   pyproject.toml
CHANGELOG.md:   N entries consolidated under [A.B.C]
Session log:    archived to .claude/archive/sessions-to-vA.B.C.md

Suggested next steps:
  git add CHANGELOG.md pyproject.toml .claude/
  git commit -m "chore: release vA.B.C"
  git tag -a vA.B.C -m "Release vA.B.C"