What Is Shadow API Discovery?

You can't protect what you don't know exists. Shadow APIs are endpoints running in production that aren't in your docs, gateway, or security review. That's the blind spot.

Where shadow APIs come from

• A v1 endpoint left running after v2 shipped (a 'zombie' API).
• A debug or internal route accidentally exposed to the internet.
• A microservice spun up by one team that security never reviewed.
• An undocumented mobile-app backend endpoint.

Why attackers love them

Shadow endpoints rarely get the same auth, rate limiting, or input validation as your documented API. Nobody's actively maintaining them, so they become soft targets for data exfiltration and abuse.

How discovery works

Spec-based inventories rely on an OpenAPI file that's usually stale. Traffic-based discovery instead watches real requests flowing through a proxy and reconstructs the true API surface from what's actually being called. New and changed endpoints surface automatically.

Karbon's shadow API discovery builds this inventory from live traffic and flags endpoints returning sensitive data, so you lock down the riskiest routes first.