Non-Human Identity (NHI)
Machine and service credentials that authenticate non-human actors—AI agents, service accounts, API keys, OAuth tokens, workload identities—to systems and other services. Non-human identities now vastly outnumber human ones in most enterprises (Gartner estimates 45:1 by 2026), and the ratio is accelerating with AI agent deployments where each agent may hold multiple tokens across CRM, email, calendar, storage, and internal APIs. NHI security is a fast-growing category because agent credentials are typically over-privileged, rarely rotated, hard to audit, and inherit blast radius from every tool they touch—making them a prime target for both direct compromise and Prompt Injection-driven abuse. The emerging fix is to give each agent its own Agent Identity and have it act through Delegated Authority (On-Behalf-Of) (OAuth OAuth Token Exchange (RFC 8693)) rather than a borrowed user token, with autonomous agents authenticated by Workload Identity (SPIFFE/SPIRE).
Written by Max Zeshut
Founder at Agentmelt · Last updated Sep 9, 2026
Example
A support AI agent is deployed with a single Slack bot token, a Salesforce integration user, a Zendesk API key, and an OpenAI/Anthropic key—four non-human identities. In a mature NHI program each is: scoped to only the actions the agent actually takes (least privilege), rotated on a fixed schedule, monitored for anomalous usage (a burst of `users.list` calls at 3am), and revocable in one action if the agent is compromised. In an immature program, one leaked key gives the attacker persistent, unmonitored access to four systems.
Frequently asked questions
- How is NHI different from traditional IAM?
- Traditional IAM assumes a human on the other end—password rotations, MFA, SSO, offboarding tied to HR events. Non-human identities have none of those signals: no manager, no offboarding, no natural expiration. They tend to accumulate over years, drift out of inventory, and share credentials across environments. NHI security tools (Astrix, Entro, Oasis, Aembit, Clutch) focus on discovery, secret rotation, least-privilege scoping, and behavioral monitoring specific to service accounts and tokens.
- What's the relationship between NHI and AI agents?
- Every AI agent that takes actions holds one or more non-human identities—the tokens it uses to call CRMs, send email, execute code, access files. Because agents often chain many tools, the average agent's blast radius is the union of all its NHI scopes. Combined with Prompt Injection risk, this makes NHI-scoping and NHI-monitoring load-bearing controls for production agent deployments.