Because the agent is not the user, and the user is not the process. Workload identity proves which runtime is acting, while delegated credentials represent whose authority it is using. If those are merged, revocation, auditing, and scope control become ambiguous, especially when the agent calls external services on the user's behalf.
Why separate the agent’s workload identity from the user’s delegated access?
The clean separation is what keeps accountability, revocation, and auditability intact. A runtime identity answers which process is acting, while delegated access answers whose authority it is using. In practice, that distinction prevents an agent from becoming a permanent proxy for a human, and it avoids ambiguous logs, overbroad scope, and hard-to-revoke access chains.
When teams collapse those two layers, they usually lose the ability to explain whether an action came from the agent’s own runtime, a user grant, or a mix of both. That matters most when the agent integrates with external systems, because the security decision is not just “is the call allowed,” but “is it allowed for this actor, in this context, for this purpose, and for how long?”
For a broader model of how AI agents should be identified, delegated to, and retired, see Agentic AI Identity Guide and AI Agent Authorisation Guide.
What breaks when runtime identity and user authority are merged?
The main failure mode is control ambiguity. If the same token, session, or account is doing double duty, revocation becomes imprecise, because you cannot cleanly remove the user’s delegated permission without also disrupting the agent’s runtime function, or vice versa. That creates hidden persistence, especially where long-lived credentials or shared secrets are reused across tasks.
Auditing also becomes weaker. A system may show that “the agent acted,” but not whether the action was part of a specific user-delegated task, a standing privilege, or an inherited session. Without that separation, it is difficult to answer basic governance questions such as who approved the action, which scope was used, and whether the agent exceeded the user’s intent.
Cloud and workload identity patterns make the distinction concrete: a runtime should authenticate as the workload, while delegated authority should be represented separately through scoped, short-lived delegation. SPIFFE and SPIRE are useful for the workload side, while Cloud Workload Identity Guide covers keyless workload access patterns that avoid static credentials.
How should delegated access be structured for AI agents?
The safest pattern is to treat delegation as a bounded authorization event, not as a new permanent identity. The agent should have its own workload identity for runtime authentication, then receive time-limited, task-scoped authority for a defined action set. That keeps the agent’s existence, the user’s intent, and the privileged operation separately visible.
That structure is especially important when the agent calls SaaS, cloud APIs, internal tools, or external services on the user’s behalf. In those cases, a single shared credential can hide whether the call was made by the agent for one approved task or reused later for a different purpose. Separate identities also make step-up approval and selective revocation practical, because you can remove delegation without dismantling the whole runtime.
For implementation depth on secure agent runtime identity and authorization paths, NHI Authentication Guide and Zero Trust for AI Agents show how to keep verification and privilege decisions separate.
Risk and Threat Considerations
When workload identity and delegated user access are collapsed, the result is often excessive privilege and unclear ownership, which creates both abuse potential and operational blind spots. The same token can then be reused outside its intended context, and an agent compromise can inherit human authority in ways that are hard to detect or unwind.
Failure mechanism: Shared or overloaded credentials blur the boundary between “who is running” and “whose authority is being exercised,” so revocation, scope reduction, and forensic reconstruction all become less reliable.
Impact: A compromised or overreaching agent can continue acting after the user believes access was removed, and security teams may be unable to prove whether a high-risk action came from the agent’s runtime or the user’s delegated grant.
Relevant control patterns are well captured in IAM and IGA Basics and the broader NHI risk taxonomy in Ultimate Guide to NHIs, Standards.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and OWASP Agentic AI Top 10 address the attack surface, NIST SP 800-53 Rev 5 and CIS Controls v8 set the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-04 — Insecure Authentication | Separate runtime and delegated auth to prevent ambiguous agent access paths. |
| NHI-05 — Overprivileged NHI | AI agents often accumulate more privilege when user and workload authority are merged. | |
| NHI-07 — Long-Lived Secrets | Merged access models often rely on reusable credentials that resist clean revocation. | |
| Recommendation — Use short-lived, distinct credentials for workload and delegated user access. Limit agent permissions to the smallest task-scoped privilege set. Replace durable shared secrets with expiring, independently revocable delegation. | ||
| OWASP Agentic AI Top 10 | ASI03 — Identity & Privilege Abuse | The question is about separating agent identity from delegated user authority. |
| Recommendation — Enforce per-action authorization and separate agent identity from user delegation. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Delegation and workload access depend on controlled credential issuance and revocation. |
| IA-9 — Service Identification and Authentication | Workload identity is the agent's runtime authentication layer. | |
| AC-6 — Least Privilege | Delegated access should be narrowly scoped to the task the agent is performing. | |
| Recommendation — Manage credential lifetime so agent and user authority can be revoked independently. Authenticate the agent as a distinct service or workload principal. Grant only task-specific permissions needed for the delegated action. | ||
| ISO/IEC 27001:2022 | A.5.15 — Access control | The subject is fundamentally about controlling and separating access paths. |
| A.8.5 — Secure authentication | Distinct authentication paths are needed for workload identity and user delegation. | |
| Recommendation — Separate access rules for runtime authentication and delegated authority. Use separate authentication mechanisms for agents and users. | ||
| CIS Controls v8 | CIS-6 — Access Control Management | The issue is scope, revocation, and control of access rights for agents. |
| Recommendation — Track and revoke agent access separately from the user account. | ||
Practitioner Guidance
What to prioritise: define two distinct records for every agent, one for runtime authentication and one for delegated authority, and require them to expire independently. If a control cannot tell you which layer is being revoked, it is not yet safe enough for production use.
What to verify: confirm that logs, approval flows, and token issuance clearly show the workload principal, the user principal, the scope granted, and the task or request that justified the delegation. If any of those fields are missing, post-incident review will be incomplete even if the transaction succeeded.
Practitioner takeaway: The goal is not to make agents less capable, it is to make their capability attributable. Separate identities let you scale delegation without turning every user approval into a standing machine privilege.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on October 10, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org