Build an OpenID Connect (OIDC) PII Catalog to Protect User Data

A single misconfigured claim in your OpenID Connect flow can leak more than you think.
It can expose the personal data you swore to protect.

OpenID Connect (OIDC) has become the default standard for authentication and identity in modern applications. It moves user profile information in JSON Web Tokens and API calls. But hidden in those claims are patterns of PII – personally identifiable information – that many teams never catalog, track, or control.

That’s the problem: if you can’t see where your PII flows, you can’t guarantee it’s safe.
Tokens pass through callbacks, stored in logs, cached in browsers, picked up by API gateways. Each claim — name, email, birthdate, address, even custom fields — can be PII. Each one has its own risk profile. Without a PII catalog for your OIDC integration, you don’t know your own exposure.

An OIDC PII catalog is simple in concept. It’s an authoritative list of every claim, attribute, and data element your system receives from your identity provider. It should flag which are PII, note how they are stored, and track their lifecycle across your services. This catalog turns OIDC from a black box into a transparent, auditable process.

A secure catalog answers these questions fast:

• Which claims do we request from the IdP?
• Which contain direct identifiers like email or phone?
• Which contain indirect identifiers like location or unique user codes?
• Where does each claim’s data go after login?

With this in place, you can review your scopes and claims, limit data requests to the minimum necessary, and apply the right encryption, masking, and retention rules. You avoid over-collection, reduce legal exposure, and keep data governance clean.

Security teams can plug in auditing and alerting to detect unexpected claims. Developers can map how claims power features without risking compliance. Managers can answer regulators with evidence, not guesswork.

The payoff is speed and safety. When engineers know exactly which OIDC claims carry PII and where they flow, they can deploy identity changes without long review cycles. Product can add secure login features without triggering data chaos.

The fastest way to see this in action is to build a live OIDC PII catalog right now. hoop.dev makes it possible to connect your identity provider, pull claims, and see the PII map in minutes. From there, you can edit scopes, tune security policies, and share the catalog with your team.

Start it today. Map your data. Protect your users.