Changelog

Subscribe to any query and get updates that keep the full type of the result. The client infers the row shape from your schema, so a subscription is as safe to use as a one-off read.

Live queries

• db.tasks.subscribe() returns a typed async iterator of rows.

• Updates are diffed on the server, so only changed rows are sent.

• Row-level rules run on every update, not just the first result.

Upgrading

Existing watch() calls keep working. Switch to subscribe() when you want inferred types and automatic reconnects.

Long migrations on large tables no longer fail with a lock timeout.

What changed

• The migration lock is now renewed while a step is running.

• tessera migrate apply reports which step holds the lock if another run is in progress.

• Added --lock-timeout for teams that want a stricter limit.

Every pull request can now get its own isolated copy of your data, so you can test a schema change against real rows without touching shared environments.

Preview branches

• Branches are created from any environment with tessera branch create.

• Copies share storage until they diverge, so creation takes seconds.

• Branches are deleted automatically when the pull request is closed.

Good to know

Branch data counts toward your storage limit while the branch exists. See the Preview branches guide in the docs for setup with your CI.

Functions now start up to 60% faster after a period of inactivity.

What changed

• Dependencies are snapshotted at deploy time instead of resolved on first call.

• The runtime keeps a small pool of warm workers per region.

• Median cold start dropped from 480ms to 190ms in our benchmarks.

A first-class, typed client for Python. It mirrors the TypeScript client so examples translate one to one.

Highlights

• Install with pip install tessera.

• Generated types from your schema through tessera generate --lang python.

• Async and sync clients, with the same query builder as TypeScript.

Session tokens now use the v2 format. Existing sessions keep working until they expire, and new sessions are issued in the new format.

Migration notes

• Custom code that decodes tokens should read the sub and exp claims from the new payload.

• The public key set is available at the same JWKS endpoint.

• Set sessionFormat: "v1" in tessera.config.ts to delay the switch by one release.

tessera init now scaffolds a project for your framework instead of a blank folder.

Templates

• Next.js, Remix, SvelteKit and plain Node are supported.

• The wizard adds .env entries and a working schema.ts.

• Run it inside an existing app to add Tessera without overwriting files.

Fixed duplicate presence events after a client reconnects.

What changed

• A reconnecting client now resumes its previous presence session instead of opening a second one.

• Stale sessions are cleaned up after five seconds.