vellum-migration-checklist

# Vellum Migration Checklist

## When A Migration Is Required

Use a migration for shipped interfaces and persisted data:

- DB schema changes, indexes, backfills, or persisted row shape changes.
- Workspace file renames, moves, format changes, or namespace changes.
- Stored config or data that existing installs must keep reading.

Do not delete migration files. Migrations are append-only, even when their logic becomes obsolete.

## DB Migrations

For DB migrations:

1. Add a new file under `assistant/src/memory/migrations/`.
2. Make it idempotent and safe to retry after interruption.
3. Register it in the migration index or registry used by DB init.
4. Update schema modules if the runtime schema changed.
5. Add or update a focused `db-*migration*.test.ts` test.

Check for ordering drift and never reorder existing migrations.

## Workspace Migrations

For workspace migrations:

1. Add a new numbered file under `assistant/src/workspace/migrations/`.
2. Append it to `WORKSPACE_MIGRATIONS` in `assistant/src/workspace/migrations/registry.ts`.
3. Make the migration idempotent.
4. Add or update a focused `workspace-migration-*.test.ts` test.

Never reuse or reorder existing migration IDs.

## Release Notes Migrations

There is currently no release-note surfacing mechanism. The update-bulletin feature (workspace migrations appending to a workspace bulletin file, processed by a background conversation at daemon startup) was removed. Do not add new `0XX-release-notes-*` workspace migrations — the historical set is frozen by `workspace-release-notes-feature-flag-guard.test.ts`. If a release needs user-facing notes, design an explicit on-demand surfacing mechanism first.

## Verification

Run the focused migration test first. Add package typecheck when migration exports, schema types, or registry wiring changed:

```bash
cd assistant && bun test src/__tests__/workspace-migration-example.test.ts
cd assistant && bun test src/__tests__/db-example-migrations.test.ts
cd assistant && bunx tsc --noEmit
```

Replace example paths with the actual test files related to the change.