Identity passthrough preserves the real actor across the request, so downstream systems can apply precise authorization and audit rules. Shared credentials collapse many actors into one account, which hides who did what and makes least privilege almost impossible to prove. For retail, that difference determines whether agent activity is traceable or effectively anonymous.
How identity passthrough differs from shared credentials
Identity passthrough keeps the originating actor attached to the transaction so downstream systems can make decisions about that specific actor, not just about an application or service container. Shared credentials, by contrast, present one reusable secret or account to many requests, which simplifies integration but removes actor-level distinction. In AI agent workflows, that difference determines whether the system can prove who acted and under what authority.
Identity passthrough also supports finer-grained authorization because the receiving system can evaluate the real principal, its delegated scope, and any policy constraints tied to the original request. Shared credentials usually flatten those distinctions into a single identity, so every caller inherits the same access path even when the underlying intent, task, or risk differs. That is why passthrough is the better model when the receiving system must enforce precise, per-actor control.
For AI agents, the practical distinction is not just technical plumbing. Passthrough allows traceability, attribution, and better separation between users, agents, and actions, while shared credentials make activity look like it came from one undifferentiated actor. If the workflow needs auditability, least privilege, or per-user accountability, shared credentials create a structural mismatch.
Why the authorization and audit outcomes are so different
Identity passthrough preserves the chain of authority from the human or upstream system into the agentic action. That means downstream services can enforce rules such as user-specific entitlements, delegated scopes, approval requirements, or context-sensitive restrictions. It also makes logs and incident investigations more useful because the event trail retains the original actor instead of collapsing everything into a service account.
Shared credentials break that chain. Once multiple agents or users operate under one account, authorization becomes coarse, and audit data stops answering the most important question: which actor actually did this? That is especially problematic where policy decisions depend on individual ownership, approval, separation of duties, or repudiation resistance. The system may still function, but it loses the ability to distinguish legitimate use from misuse at the actor level.
In practice, passthrough is closer to delegated authority, while shared credentials are closer to pooled access. AI Agent Authorisation Guide is useful background when you need to design task-scoped access and per-action policy decisions around that distinction.
What breaks when agents share one account
Shared credentials create a single blast radius for every caller that can reach them. If the secret leaks, every workflow using it is exposed; if one agent is compromised, the attacker inherits the same access as every other actor using that secret. The operational convenience is real, but it comes at the cost of weak accountability and a much harder containment story.
They also make governance harder over time. You cannot easily prove least privilege when many different tasks, environments, or teams all rely on the same credential, because the access path is broader than any one actor actually needs. Rotation, revocation, and offboarding become blunt instruments rather than targeted controls, which increases the chance of accidental service disruption or lingering access.
That is why broad reuse patterns deserve scrutiny in AI agent programs. Top 10 Agentic AI Identity Issues and OWASP Non-Human Identity Top 10 both reinforce the same operational lesson: shared access materialises risk fastest when identity boundaries are vague and credentials outlive the task they were meant to serve.
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 sets the technical controls, and ISO/IEC 27001:2022 defines the regulatory obligations.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | Shared credentials usually collapse many actors into one overbroad account. |
| Recommendation — Avoid pooled access and scope each agent credential to the minimum needed authority. | ||
| OWASP Agentic AI Top 10 | ASI03 — Identity & Privilege Abuse | Passthrough vs shared credentials changes how agent authority is assigned and abused. |
| Recommendation — Preserve actor identity and enforce per-action authorization for agent requests. | ||
| NIST SP 800-53 Rev 5 | IA-2 — Identification and Authentication (Organizational Users) | Downstream systems need reliable actor identification to distinguish requesters. |
| IA-5 — Authenticator Management | Shared credentials hinge on secret lifecycle, rotation and revocation risk. | |
| AU-2 — Event Logging | Passthrough is materially better when audit trails must retain actor attribution. | |
| Recommendation — Authenticate the real actor rather than collapsing many users into one shared account. Manage credential issuance, rotation and revocation tightly to limit shared-secret exposure. Log the originating principal so actions remain attributable in investigations. | ||
| ISO/IEC 27001:2022 | A.5.15 — Access control | The subject is fundamentally about how access is represented and constrained. |
| A.8.5 — Secure authentication | Identity passthrough and shared credentials differ in how authentication is represented downstream. | |
| A.8.15 — Logging | Auditability depends on whether logs retain the originating actor or only a shared account. | |
| Recommendation — Define access rules that preserve actor-level accountability wherever possible. Use authentication methods that preserve trustworthy identity assertions end to end. Record the originating principal and action context in security logs. | ||
Practitioner Guidance
What to prioritise: Use identity passthrough when the downstream system must know which actor initiated the action, and reserve shared credentials only for narrow technical cases where actor-level accountability is genuinely unnecessary.
What to verify: Confirm that downstream authorization, logging, and incident response can still answer three questions clearly: who acted, what authority they had, and whether the action can be separated from other users or agents.
Common mistake: Treating shared credentials as “simpler” identity management when they are often just deferred governance debt. They reduce implementation work up front but usually increase investigation time, privilege sprawl, and revocation complexity later.
Practitioner takeaway: If an AI agent can cause business impact, preserving the real actor through passthrough is usually the difference between controlled delegation and anonymous pooled access.
Related resources from NHI Mgmt Group
- What is the difference between workload identity and API keys for AI agents?
- What is the difference between managed identities and hardcoded secrets for AI agents?
- What is the difference between human identity governance and AI agent governance?
- What is the difference between logging actions and logging intent for AI agents?