What Is a Non-Human Identity (NHI)?

A non-human identity (NHI) is a digital identity assigned to software rather than a person — such as an API key, OAuth token, service account, SSH key, or certificate. Machines, microservices, CI/CD pipelines, and AI agents use these credentials to authenticate to other systems. In most environments, non-human identities now vastly outnumber human ones.

How non-human identities work

Every time one piece of software talks to another — an app calling a payment API, a deployment script pushing to a cloud account, an AI agent querying a database — it needs to prove who it is. People do this with usernames, passwords, and multi-factor authentication. Software does it with a non-human identity: a secret credential that stands in for an account.

That credential might be a long-lived API key, a short-lived OAuth access token, a service account JSON file, an SSH key pair, or a TLS client certificate. Whatever the format, the principle is the same: possession of the secret is the identity. Anyone — or anything — holding it can act as that machine.

Why non-human identities matter

The scale is the first problem. A single engineer might have one or two human logins, but the services they ship can spawn dozens of machine credentials. Analysts estimate NHIs outnumber human identities by an order of magnitude or more, and the non-human identity access management market is growing rapidly as organizations adopt microservices, cloud automation, and AI agents.

The second problem is governance. Human accounts are offboarded when someone leaves; non-human identities often live indefinitely. They are routinely over-permissioned, rarely rotated, and frequently lack a clear owner who knows what they do. Worse, their secrets get hardcoded into source code, pasted into Slack, or saved in config files — which is exactly how secret sprawl begins.

For attackers, this makes NHIs an ideal target. A leaked machine credential is often valid for months, grants broad access, and triggers no MFA prompt. That is why secret scanning and NHI governance have become core parts of modern application security.

Common types of non-human identity

• API keys and tokens — used by apps and integrations to call third-party services.
• Service accounts — cloud or platform accounts created for automation rather than people.
• SSH and signing keys — authenticate machines and verify code.
• Certificates — establish trust between services (mTLS, code signing).
• AI-agent credentials — the fastest-growing category, as autonomous agents act on behalf of systems.

Frequently asked questions

What is an example of a non-human identity?

Common examples include API keys, OAuth tokens, service accounts, SSH keys, TLS certificates, and the credentials CI/CD pipelines, microservices, and AI agents use to authenticate.

What is the difference between a human and a non-human identity?

A human identity belongs to a person and is usually protected by a password plus MFA. A non-human identity belongs to software and authenticates with a secret like a key or token — often with no MFA and a far longer lifespan.

Why are non-human identities a security risk?

They are numerous, often over-permissioned, rarely rotated, and frequently ownerless. Their secrets leak into code and chat, making them long-lived, high-value targets.