What Is a Non-Human Identity (NHI)? Definition and Governance

Defining Non-Human Identity

A non-human identity is any digital identity that authenticates and acts on behalf of a system rather than a person. This category includes long-standing constructs such as service accounts and API keys, as well as newer forms like workload identities and AI agent identities that may be created dynamically at runtime. NIST SP 800-207, the Zero Trust Architecture standard, formally recognizes non-person entities as a distinct subject category that must be authenticated and authorized alongside human users. This distinction matters because NHIs typically authenticate through API keys, certificates, tokens, or workload identity federation rather than the passwords and multi-factor authentication mechanisms used for people. The result is a fundamentally different trust and control surface that most identity programs were not built to address.

How NHIs Differ From Human and Service Account Identities

Human identity governance relies on HR-driven joiner-mover-leaver triggers: a person is hired, changes roles, or leaves, and provisioning systems respond accordingly. Traditional service accounts break that model somewhat, since they are typically static, long-lived, and manually provisioned by an engineering team rather than tied to an HR event. AI agent identities introduce a further layer of complexity. They may be created dynamically, chained together, or delegated at runtime, meaning an agent can act on behalf of another agent or a user without a corresponding standardized creation or decommissioning trigger. This makes it harder to answer basic governance questions: who owns this identity, when should it expire, and what is it currently permitted to do.

Identity Types Compared

The table below summarizes how human identities, traditional service accounts, and AI agent identities differ across the attributes that matter for governance design.

Why Existing IAM and IGA Approaches Fall Short

Most identity and access management and identity governance and administration platforms were architected around directory-based human identities. They assume a relatively stable population of subjects with predictable lifecycle events and do not natively model machine-specific attributes such as originating workload, credential type, or delegation chain. Credential and secret rotation for NHIs is frequently handled by separate vault or secrets-management tooling that is disconnected from the core identity governance system, which fragments oversight rather than consolidating it. Federation between cloud-native workload identity systems and enterprise IAM platforms is often incomplete, creating visibility gaps across hybrid environments. The consequence, documented in guidance from organizations including OWASP through its Non-Human Identities project, is a recurring set of risks: improper credential offboarding, overprivileged access, and identities that persist long after the workload or agent they supported has been retired.

Core Components of an NHI Governance Framework

Enterprises that treat non-human identity as a distinct control domain typically assemble the following building blocks.

• A single inventory or system of record for all NHIs across cloud, SaaS, and on-premises environments
• Ownership assignment at provisioning time, so every NHI maps to an accountable human or team
• Least-privilege permissioning that extends to dynamically created or chained agent identities, not only static service accounts
• Automated credential and secret rotation policies to reduce reliance on long-lived static keys
• Runtime authorization checks that constrain agent actions as context changes, supplementing provisioning-time grants
• Audit logs that capture which NHI performed an action, under what delegated authority, and on whose behalf

Operational Practices for Managing NHIs at Scale

• Distinguish static from dynamic identities: Provisioning and deprovisioning logic must account for the difference between long-lived service accounts and agent identities instantiated at runtime.
• Model delegated authority explicitly: When an agent acts on behalf of another agent or a user, the identity architecture needs to represent multi-hop authorization rather than a single subject-to-resource relationship.
• Separate provisioning-time and runtime enforcement: Permissions granted at creation are not sufficient; enforcement points that evaluate authorization at the moment of action are architecturally distinct and necessary.
• Normalize machine logs into existing SIEM pipelines: Logging schemas built for human session activity often miss machine-specific attributes needed for attribution, so these fields must be captured and standardized.
• Set recertification cadences for NHIs: Credential issuance and permission grants for non-human identities should be reviewed on a defined schedule, comparable to human access recertification.