How should security teams build a continuous inventory for machine identities?

Why This Matters for Security Teams

A continuous inventory is the difference between knowing a machine identity exists and knowing whether it can still be used. Service accounts, API keys, workload identities, and certificates tend to proliferate faster than people can track, and manual reviews miss the identities that are created by automation, embedded in CI/CD, or inherited through third-party integrations. NHI Management Group research shows that only 5.7% of organisations have full visibility into their service accounts, which is why discovery has to be continuous rather than periodic. For context on lifecycle and Zero Trust expectations, see the Ultimate Guide to NHIs and the NIST Cybersecurity Framework 2.0.

The practical failure mode is not simply “missing assets.” It is missing ownership, missing expiry dates, and missing revocation paths, which means security teams cannot answer basic questions fast enough during an incident or audit. A live inventory should therefore behave like a control plane, not a spreadsheet. It needs to reconcile what scanners see, what endpoint telemetry reveals, and what identity and secret-management systems already know, then keep those records current as applications change. In practice, many security teams encounter expired or over-privileged machine identities only after a breach or service disruption has already exposed the gap.

How It Works in Practice

The strongest pattern is to treat inventory as an always-on reconciliation process. Active discovery finds identities that still exist in cloud accounts, code repositories, certificates, and directories. Endpoint telemetry shows where workloads actually run and which binaries, agents, and services are using credentials. API integrations then enrich the record with authoritative metadata from IAM, PAM, secrets managers, certificate authorities, ticketing systems, and cloud control planes. That is the operational model NHI Management Group recommends for modern NHI governance, and it aligns with lifecycle thinking in the Ultimate Guide to NHIs.

Each inventory record should minimally include identity type, owner, business service, source system, credential or certificate type, issuance date, expiry or rotation date, privilege scope, last-seen timestamp, and revocation state. For machine identities used by autonomous software entities or AI agents, the record should also capture workload identity and runtime policy context, because behaviour changes as the toolchain changes. That is where identity becomes operational control rather than documentation.

• Use discovery to find candidates, then de-duplicate them against the authoritative source of truth.
• Normalize ownership so every identity maps to a named team, not just a platform.
• Attach TTL, rotation policy, and revocation workflow at creation time, not after review.
• Feed changes into PAM, RBAC, and secret managers so the inventory stays actionable.

For implementation detail, pair this with the control expectations in NIST Cybersecurity Framework 2.0 and, where automation is involved, validate runtime decisions against policy rather than static labels. The guiding idea is that the inventory should explain who can act, with what secret, on which system, and until when. These controls tend to break down when identities are created and destroyed inside ephemeral pipelines or containers faster than the reconciliation jobs can ingest telemetry.

Common Variations and Edge Cases

Tighter inventory control often increases operational overhead, so organisations have to balance completeness against the cost of constant reconciliation. In mature environments, that tradeoff is usually worth it because the alternative is stale ownership and unmanaged expiry. In more dynamic environments, current guidance suggests using shorter polling windows, event-driven updates, and automated enrichment rather than trying to force a weekly review cycle onto infrastructure that changes every minute.

There is no universal standard for every edge case yet. For short-lived jobs, the inventory may need to track the workload template rather than each ephemeral instance. For third-party integrations, the record should distinguish between the external owner of the application and the internal owner of the connected trust relationship. For agentic systems, the inventory should capture the agent’s tool access and issuance path, not just the token it happened to use at a point in time. That distinction matters because autonomous systems can chain actions, request new access, and alter their own execution path faster than traditional review processes assume. The JetBrains GitHub plugin token exposure illustrates how quickly a single exposed token can turn into broad inventory drift when it is not tied back to ownership and expiry controls.

For teams building toward Zero Trust, the right question is not whether an identity exists, but whether it is still valid, still needed, and still constrained. That mindset also matches the governance direction in the NIST Cybersecurity Framework 2.0. In practice, inventory efforts fail when discovery, ownership, and revocation are run by different teams with no shared reconciliation process.

Related resources from NHI Mgmt Group

• How should security teams govern machine identities in manufacturing environments?
• How should security teams reduce secret sprawl in machine identities?
• How should security teams govern machine identities separately from other NHI types?
• How should security teams govern machine identities in software supply chains?