This post covers Kit v2026.6.4. The detailed notes below come from the project changelog.
Kit 2026.6.4 is a compiler, type-checker, LSP, security, package, and agent lifecycle
release. It completes linear ownership checking, closes object-capability gaps, fixes capability-aware
package checking, improves editor quick fixes and parser recovery, and adds supervised agent lifecycle
support. It also fixes kit:test release blockers and renames the internal nil sentinel to unit so
implementation terminology matches Kit's unit value, including generated wrapper handling.
The docs and release materials were refreshed for the new version as well: package dependency metadata no longer carries version-only dependencies, doc checking handles ADT constructors more cleanly, and the TODO cleanup work removed stale parser comments and remaining scan concerns.
Release Snapshot
- Release: v2026.6.4
- Date: June 4, 2026
- Changelog entries: 17
- Primary areas: agent lifecycle supervision, linear ownership, object capabilities, package capability checks, LSP recovery and quick fixes, documentation checking, package metadata cleanup, kit:test release readiness, nil sentinel cleanup
What Changed
Agent support now includes supervised lifecycle handling, giving agent-oriented packages a clearer path for startup, restart, and teardown behavior.
Linear ownership checking is now complete across the language surface. The checker tracks linear, affine, relevant, and borrowed uses through bindings, destructuring, branch paths, match macros, contracts, refinements, macro expansion, and imported aliases.
Capability hardening closes object-capability gaps and fixes package-aware capability checking. Normal
application code should derive authority from env.root and pass narrow tokens explicitly;
direct authority constructors remain reserved for tests.
The LSP has better quick fixes and parser recovery, so editor features keep working more reliably while code is incomplete or temporarily malformed during edits.
Release Highlights
- Add supervised agent lifecycle support.
- Complete linear ownership checking across expressions, patterns, macros, contracts, and imports.
- Close object-capability gaps and harden capability-aware package checking.
- Improve LSP quick fixes and parser recovery.
- Fix doc checker ADT constructor warnings.
- Remove version-only package dependencies and stale TODO scan concerns.
- Fix kit:test release blockers and refresh release metadata.
- Rename the internal nil sentinel to unit and fix generated wrapper nil sentinel handling.
Exact Changelog
The list below matches the 2026.6.4 changelog entry, with each short SHA linked to the
corresponding GitLab commit in kit-lang.
- Add supervised agent lifecycle support (7185271)
- Fix doc checker ADT constructor warnings (660fa7b)
- Close object capability gaps (f49a023)
- Complete linear ownership checking (1743014)
- Remove stale parser TODO comments (29525ac)
- Remove version-only package dependencies (428941e)
- Fix remaining TODO scan concerns (dcbf5ce)
- Add GitLab work item label guidance (077ce8b)
- Improve LSP quick fixes and parser recovery (7470bfb)
- Commit remaining release and safety updates (4fa0308)
- Refreshed CHANGELOG.md (8b41b99)
- Fix capability-aware package checking (c349461)
- Rename internal nil sentinel to unit (49b1821)
- Updated to Kit 2026.6.4 (f4cc3d1)
- Fix kit:test release blockers (413f60b)
- Refreshed CHANGELOG.md (0d61578)
- Fix generated wrapper nil sentinel (5965618)