Keycloak Row-Level Security

Keycloak Row-Level Security is not a feature you toggle. It is an architecture you design. Keycloak handles identity, tokens, and claims. Row-level security (RLS) lives inside your database. The key is making them talk in real time without losing milliseconds or clarity.

First, understand the layers. Keycloak issues OAuth2 or OpenID Connect tokens with custom claims—such as roles, department IDs, or tenancy identifiers. These claims must be passed unchanged to the application tier. Your application then maps claims to database session settings. In PostgreSQL, that means setting GUC parameters or using SET SESSION variables before queries run.

The RLS logic in the database references these variables in policies:

CREATE POLICY department_rls
ON documents
FOR SELECT
USING (department_id = current_setting('app.department_id')::int);

This policy ensures that queries only return rows matching the department claim from Keycloak. No client bypass exists because it’s enforced at the database level.

Integrating Keycloak with RLS has sharp edges.

• Token parsing: Strip values from JWTs securely.
• Session binding: Ensure the claim-to-session mapping is atomic to prevent leakage between users.
• Revocation: Keycloak token introspection endpoints can be used to validate sessions before each request, but balance it against performance.
• Caching: If claims rarely change, cache parsed tokens for speed while respecting expiry.

For multi-tenant applications, add the tenant ID to claims and enforce via RLS policies. This creates isolation without separate databases. Each row belongs to a tenant, and policies prevent cross-tenant reads or writes.

Auditing is essential. Enable database logs for RLS policy hits and misses. Pair this with Keycloak event logging to trace how identities translate to data visibility.

The payoff: one identity provider, one unified policy set, rows locked down to only the right eyes. No redundant authorization logic scattered across services. The control lives with the database, and Keycloak drives the context.

Want to see Keycloak Row-Level Security in action without weeks of setup? Spin it up on hoop.dev—connect your database, link Keycloak, apply policies, and watch it go live in minutes.