Asset inventory

Shadow and zombie APIs: detection and cleanup

Find undocumented endpoints, deprecate safely, and keep your inventory tight.

Published: February 3, 2026 • Author: APISAST

Why they appear

Shadow APIs come from rogue teams or forgotten prototypes; zombie APIs linger after migrations. Both widen your attack surface and often skip auth and observability.

Discovery tactics

  • Compare ingress logs against the official OpenAPI inventory.
  • Scan source repos for router definitions that lack spec coverage.
  • Use eBPF or service mesh telemetry to spot untracked services.
  • Run external scanners and correlate findings with your spec.

Mitigation

  • Deprecate with timelines and clear RFC 7807 errors for retired routes.
  • Disable or rate-limit legacy endpoints; add auth immediately.
  • Automate weekly inventory checks in CI with SAST testing for APIs.
  • Assign ownership for every service and spec.
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