Treat the agent as its own identity subject, not as an extension of the human user. Bind every delegated action to a specific purpose, merchant context, and expiry condition, then log the proof that links the agent's activity back to the authorising user.
Delegated identity should be governed as a scoped authority, not a proxy for the user
Agentic commerce works only when the agent has a clearly bounded mandate. Security teams should treat delegated identity as a separate control plane with its own subject, permissions, and expiry, rather than letting the human’s full trust implicitly flow through every checkout, purchase, or negotiation action.
The practical test is whether the delegation can be described without ambiguity: who authorised it, what merchant or marketplace it applies to, what the agent may do, and when that authority ends. Agentic Commerce Identity Guide is useful because it centres the mandate model behind agent payments and verifiable intent.
That separation matters because the merchant sees the agent in the transaction path, but the governance question is still about provenance and scope. If the delegated action cannot be tied to a specific purpose and context, then the agent is effectively operating on open-ended authority, which is the wrong trust model for commerce.
What the policy should bind on, and what should remain immutable
Good delegated identity policy binds the action to three things: purpose, merchant context, and expiry. Purpose prevents a general token from being reused for unrelated buying or account management. Merchant context prevents the same delegation from being replayed across stores, platforms, or subsidiaries. Expiry ensures authority does not outlive the commercial need that created it.
Security teams should also decide which elements are immutable after issuance. The authorising user, the agent subject, the merchant boundary, and the maximum transaction scope should not be modifiable by the agent itself. Where the business needs more flexibility, use a new delegation record rather than widening the original one.
For implementation design, this is where task-scoped access and just-in-time authority matter most. AI Agent Authorisation Guide is directly relevant because it focuses on per-action policy decisions, least privilege, and approval gates for agent behaviour.
Delegation also needs lifecycle control. A merchant mandate that cannot be expired, rotated, or revoked on demand will eventually become overbroad, especially when it is reused across workflows. Agentic AI Identity Guide supports the identity lifecycle view, including delegation, ownership, and retirement of agent authority.
Proof, attribution, and auditability are part of the control, not an afterthought
Every delegated action should produce evidence that links the agent’s activity back to the human authoriser. That evidence needs to be durable enough for dispute handling, fraud review, and internal investigation. At minimum, teams should retain the delegation record, the merchant context, the policy decision applied at the moment of action, and the transaction or tool call identifier.
This is where logging must capture attribution, not just event volume. Teams need to be able to reconstruct why the agent was allowed to act, under whose authority, and whether the action stayed inside the approved boundary. AI Agent Observability, Audit and Incident Response Guide is the most direct match for action attribution, audit trails, and incident response evidence.
For commerce-specific governance, the proof model should also support merchant-side disputes and payment traceability. That means the log record should preserve a human-readable explanation of the mandate, not just opaque token metadata. When the proof is weak, every downstream control gets harder, from chargeback analysis to abuse detection.
Risk and Threat Considerations
Delegated identity in agentic commerce creates a concentrated trust path: if scope is too broad, an agent can spend, commit, or negotiate outside the user’s intent without any obvious break in the transaction flow. The main risk is not only outright compromise, but also silent overreach caused by stale mandates, reusable tokens, or merchant scope that is too wide.
Failure mechanism: The delegation is treated as a reusable proxy for the person instead of a bounded authority with explicit purpose, merchant context, and expiry. That allows misuse, replay, or over-automation to look legitimate at the point of sale even when it no longer matches the authorising intent.
Impact: Financial loss, dispute exposure, failed accountability, and weak non-repudiation follow when teams cannot prove which human authorised the action, what was allowed, and whether the agent stayed within scope. At scale, the same weakness can turn into broad merchant or platform abuse.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10 and OWASP Non-Human Identity 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 |
|---|---|---|
| OWASP Agentic AI Top 10 | ASI03 — Identity & Privilege Abuse | Delegated commerce identity is fundamentally about preventing agent privilege from exceeding user intent. |
| ASI09 — Human-Agent Trust Exploitation | The question centers on how human intent is safely represented and not overextended by an agent. | |
| Recommendation — Enforce per-action authorization and bound delegated privilege to the merchant and purpose. Require explicit mandate proof and confirmation boundaries before agents can act on behalf of users. | ||
| NIST SP 800-53 Rev 5 | IA-9 — Service Identification and Authentication | Agent-to-merchant delegation depends on authenticating non-human actors that act with authority. |
| AC-6 — Least Privilege | Delegated identity must constrain agent actions to only the minimum authority needed for each transaction. | |
| AU-2 — Event Logging | The answer depends on retaining proof that links agent activity back to the authorising user. | |
| Recommendation — Authenticate the agent as a distinct subject before granting commerce authority. Limit each delegation to the smallest viable commerce scope and duration. Log mandate issuance, policy decisions, and transaction identifiers for attribution. | ||
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | An agent acting for commerce can become dangerously overprivileged if delegation is too broad or reusable. |
| NHI-07 — Long-Lived Secrets | Delegated commerce authority becomes risky when tokens or credentials outlive the intended purchase window. | |
| Recommendation — Constrain non-human commerce credentials to merchant-specific, purpose-bound permissions. Replace long-lived delegated credentials with short-lived, revocable authority. | ||
Practitioner Guidance
What to verify: Confirm that every delegated commerce flow has an explicit owner, a bounded purpose string, a merchant or domain restriction, and a hard expiry. If any one of those fields is missing, treat the delegation as incomplete and do not let it reach production checkout paths.
What to measure: Track the share of delegated actions that are backed by a fresh policy decision and a unique mandate record, not a long-lived bearer credential. Also watch for delegated identities that are reused across merchants or survive beyond the original purchase window, because those are early signs that scope control is eroding.
Common mistake: Teams often secure the payment rail but leave the delegation layer vague. The better control is to make the agent’s authority narrow enough that the transaction can be trusted even when the merchant, the model, or the workflow changes.
Practitioner takeaway: In agentic commerce, the security boundary is the mandate, not the model. If you can’t prove what the agent was authorised to do, where it applied, and when it expired, you do not have governed delegation.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Free weekly newsletter
Subscribe to the NHI & AI Identity Journal
The latest on NHI and Agentic AI security – articles, research, breaches, news and events every week.
Bonus 33% off our NHI Course when you subscribe.
Reviewed and updated by the NHIMG editorial team on October 6, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org