the migration tag this upload advances to (e.g. "v1").
Optionalold_the tag the server must currently be at — optimistic concurrency; omit on the first deploy.
Optionalnew_classes to create with the SQLite storage backend (Agents SDK requirement).
Optionalnew_classes to create with the legacy key-value backend (Paid plan only).
Optionalrenamed_Optionaldeleted_
A Durable Object migration, INLINE in the script-upload metadata (NOT the D1
Migrationin resources.ts — that is SQL run against a database; this is a declarative tag that tells Workers a DO class exists and which storage backend it uses). NB the wire field isnew_tag(+ optionalold_tag), unlike wrangler.jsonc which usestag.new_sqlite_classesis what the Agents SDK + the Workers free plan require;new_classesis the legacy KV backend.