Turso

Turso is a database platform built on the SQLite lineage. Three related things carry the name. SQLite itself is the original engine. libSQL is Turso's MIT-licensed fork of SQLite, created because SQLite, though public domain, does not accept outside contributions. Turso Database is a newer rewrite of SQLite in Rust, also MIT, which runs in-process and has an experimental Postgres frontend. Turso Cloud is the managed platform that hosts databases of both kinds, adding branching, backups, analytics and an HTTP API. Embedded replicas are a distinctive part of the model: an application keeps a local copy of the database file, reads from it at local file speed, and forwards writes to the primary, with the replica synchronising afterwards. The distinguishing idea is per-tenant isolation at a price that makes it practical. In a shared Postgres, tenant isolation is a WHERE clause and a code review; a per-tenant database gives you a real boundary, per-tenant backup and restore, per-tenant deletion that actually deletes, and a noisy neighbour who can only affect themselves. Doing that on Postgres means either a schema per tenant, which becomes unmanageable in the thousands, or a cluster per tenant, which is unaffordable. A SQLite database is a file, so the marginal cost of the ten-thousandth is close to nothing. That is a genuine architectural capability rather than a repackaging, and it is why Turso appears in multi-tenant SaaS and in agent products that want a scratch database per session. The buyers are teams building multi-tenant applications and agent infrastructure who want isolation without operating a fleet of database servers. The trade-off is that you inherit SQLite's model wholesale. One writer per database means a single tenant's write concurrency does not scale, and there is no sharding a hot tenant. Cross-tenant queries do not exist, since ATTACH is deprecated on the cloud, so any report spanning customers has to be assembled elsewhere. Schema migrations fan out across every database and must be idempotent and resumable, and multi-database schemas, the feature intended to solve exactly that, is itself deprecated. So is Data Edge, the multi-region edge replication that was Turso's original pitch, which means a good deal of the writing about Turso describes a product that no longer works that way.