history

Launcher reads the single App definition

id: LK-20260716-launcher-definition-metadata
date: 2026-07-16
sequence: 78
type: refactor
compatibility: compatible
component: `labkit_launcher` | `1.5.0 -> 1.5.1`
scope: App discovery
scope: Product metadata ownership

Context

The launcher discovered entrypoints independently from App runtime creation, but obtained versions by parsing a separate package version.m. That kept the old metadata file alive even after Runtime V2 gained a single definition contract.

Decision and rationale

Keep discovery lightweight and self-contained while changing its source of truth. The launcher now reads AppVersion and Updated literals from the App's definition.m; it does not execute the definition or start the App.

Changes

• Preferred definition.m product metadata during public and private App discovery.
• Added a synthetic private-App catalog test with no version.m file.
• Retained a documented internal fallback only for Apps awaiting migration.

User and data impact

Launcher catalogs continue to show version and update dates. A migrated App does not need a second metadata file solely for discovery.

Compatibility and migration

The change is compatible. Existing Apps remain discoverable through the temporary fallback; migrated Apps use only their definition. The fallback is removed after the last App migration.

Validation

The launcher catalog test creates an isolated App definition, points private discovery at it, and verifies the returned version and date without a version.m file.

Evidence

• LabKit Launcher explains definition-backed discovery.
• Runtime and Lifecycle defines the App product metadata fields.

Known limitations and follow-up

P-code packaging metadata will be audited with the deployment workflow before the transitional parser fallback is removed.