ai-persistence/build-cloudflare-adapter

Export a factory function that builds a ChatPersistence from the request's D1 binding, since bindings are unavailable at module scope. Implement the messages, runs, interrupts, and metadata stores against d1.prepare(sql).bind(...), then pass the result to withPersistence middleware.

Use Drizzle if the app already depends on drizzle-orm and has a schema file, wrapping the binding with drizzle(env.DB, { schema }). Otherwise implement the four stores directly against raw D1 prepared statements, which mirror the node:sqlite walkthrough since D1 speaks SQLite.

Cloudflare D1 bindings only exist per request through the env argument, so a module-scope const cannot access them. The adapter must be a factory called inside the fetch handler; building it per request is cheap because stores hold no state beyond the binding.

Add a Durable Object LockStore only when middleware needs mutual exclusion across Worker isolates, since InMemoryLockStore provides none. It uses leases with expiry and alarms so a crashed owner cannot block a key forever.

Run runPersistenceConformance from @tanstack/ai-persistence/testkit against a Miniflare D1 binding with the migration applied, resetting between runs. Declare unimplemented optional runs methods in skipMethods and skipped generation stores in skip.