Tenant isolation
The set of architectural and database guarantees that ensure one user's data cannot leak to another user. In Ajeris, implemented via per-user database partitioning with row-level security plus an application-side context wrapper plus pre-launch security guards.
Why it matters
Multi-user products that share infrastructure (most SaaS) need isolation guarantees. A bug, a misconfiguration, or a vulnerability anywhere in the stack can leak data across tenants. For an AI agent that holds memories, conversations, tool credentials, and customer data, the radius of "what bad looks like" is large; the defenses have to be correspondingly strong.
The history of multi-tenant security incidents shows that single-layer defenses fail predictably. Three layers of defense (database + application + pre-launch checks) is the working pattern.
How Ajeris handles this
Three layers. First, per-user database partition with row-level security enforced by Postgres. Second, an application-side context wrapper that scopes every query to the current user. Third, pre-launch security guards that block any commit that introduces a tenant-leak vector. The guards run on every push and on CI; bypassing them requires explicit override.
