A delegated chain is the sequence of identities and permissions passed from one actor to another when a request is relayed through multiple services or agents. In identity security, it records who acted on whose behalf, preserving accountability, limiting privilege spread, and supporting audit, policy enforcement, and incident investigation.
What a delegated chain captures
A delegated chain records the path of delegated authority as a request moves through services or agents, so the system can distinguish the original initiator from each intermediary acting on its behalf. It is less about transport and more about preserving a trustworthy permission lineage.
This matters when multiple components can invoke downstream actions, because the security question is not only “did the request succeed?” but “which identity exercised which permission at each step?”
Why delegated chains matter for accountability
Delegated chains help preserve attribution when a service forwards a request, when an integration broker calls another API, or when an agent acts with borrowed authority. Without that lineage, audit records blur together and it becomes harder to prove which actor was responsible for a sensitive action.
That accountability is what makes delegated chains useful in incident investigation, access review, and policy enforcement. They support the distinction between delegation and impersonation, especially where the downstream system must know whether it is seeing the caller’s authority, a constrained delegated token, or a more direct form of trust transfer.
How delegated chains shape authorization decisions
A delegated chain is most valuable when each hop can narrow privilege instead of widening it. The chain can carry claims such as the acting principal, the original subject, and any downscoped permissions so downstream services can enforce least privilege at each step rather than accepting a broad upstream identity.
In practice, the chain should make it possible to evaluate whether a service is authorized to act for someone, and if so, under what limits. That is what prevents a relayed request from becoming an open-ended privilege pass-through.
For implementations that use token exchange and on-behalf-of delegation, NHIMG’s OAuth Token Exchange and Delegation Guide is the clearest companion reference for act claims, subject tokens, and delegated access chain.
Where delegated chains fail in real systems
Delegated chains break down when intermediaries drop provenance, when tokens are reused outside their intended context, or when systems treat delegated authority as if it were full impersonation. They also fail when logs capture the final action but not the full chain of custody, leaving no reliable way to reconstruct who actually exercised privilege.
In agentic or service-to-service environments, the same weakness can cascade across multiple hops, because one over-broad delegation can be repeated and amplified by later components. The result is often excessive access, poor forensic clarity, and weaker policy enforcement at the point of action.
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 API Security Top 10 address the attack and risk surface, while NIST SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-9 — Service Identification and Authentication | Delegated chains depend on services proving and preserving who is acting for whom across hops. |
| AC-3 — Access Enforcement | A delegated chain exists to constrain what each actor may do when authority is relayed. | |
| AU-3 — Content of Audit Records | Delegated chains need audit records that preserve actor lineage and authorization context. | |
| Recommendation — Use IA-9 to authenticate service-to-service calls and preserve authority lineage across delegated requests. Enforce AC-3 so each hop only receives the permissions needed for the delegated action. Record original subject, intermediary actor, and delegated context in audit logs for each sensitive action. | ||
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | Delegated chains can spread excessive privilege if delegated authority is not downscoped at each hop. |
| Recommendation — Downscope delegated permissions to prevent overprivileged non-human identities from propagating access. | ||
| OWASP API Security Top 10 | API5 — Broken Function Level Authorization | Delegated chains often traverse APIs where each function must verify the caller's delegated authority. |
| Recommendation — Verify function-level authorization on every hop so delegated requests cannot trigger unauthorized actions. | ||
Related resources from NHI Mgmt Group
- How should security teams reduce supply chain risk when third-party integrations hold delegated access to critical SaaS data?
- What breaks when an AI agent platform cannot revoke delegated access across the full agent chain?
- Why do delegated identities and CI/CD runners create supply chain risk?
- Delegated Access Chain