The regulated problem

An agent processing EU personal data must honour GDPR Article 5(1)(b) purpose limitation and keep sessions, memory, and artifacts inside a permitted region — with a guarantee it fails closed rather than leaking data across a boundary when residency can't be satisfied.

How Regulus handles it

Purpose limitation at the tool boundary

The GDPR profile encodes Article 5(1)(b) as runtime policy. The policy and privacy plugins evaluate purpose and redact PII on every tool call — turning a written principle into an enforced control.

Residency that fails closed

RegulusVertexAiSessionService and RegulusGcsArtifactService extend Google's own session and artifact services to pin writes to the resolved region. If residency can't be satisfied, the data-residency plugin denies the write rather than allowing it.

Retention resolved across profiles

When GDPR composes with other profiles, the retention compactor applies the strictest retention that wins, so events older than the resolved policy are compacted automatically.

Install in 60 seconds See the audit envelope

Regulus is the open-source EU + UK compliance plane for Google ADK, a project by Neul Labs.