Agent authorization needs both gateway and token models

At a glance

What this is: This is a practitioner analysis of two runtime authorization models for AI agents, concluding that gateway and token-based approaches solve different governance problems.

Why it matters: It matters because IAM, NHI, and agentic AI teams need to align authorization design with system sensitivity, auditability, and data-path privacy instead of standardising on a single control pattern.

By the numbers:

• Only 5.7% of organisations have full visibility into their service accounts.
• 80% of identity breaches involved compromised non-human identities such as service accounts and API keys.
• 96% of organisations store secrets outside of secrets managers in vulnerable locations including code, config files, and CI/CD tools.

👉 Read C1.ai's analysis of gateway and token authorization for AI agents

Context

Agent authorization decides how a software actor gets permission to act at runtime. In this case, the primary identity subject is the AI agent, and the article compares a proxy gateway model with a standards-based short-lived token model for controlling access to applications.

The governance issue is broader than a single product choice. IAM and NHI programmes have to decide whether they want central visibility, direct access, or both, depending on system sensitivity, audit expectations, and whether a provider can sit in the data path without creating its own risk.

Key questions

Q: How should security teams choose between gateway and token authorization for AI agents?

A: Choose the model based on the system’s sensitivity and control objective. Use a gateway when you need deep inspection, real-time policy enforcement, and full transaction logs. Use short-lived tokens when direct access, lower latency, and data-path privacy are more important. In mature programmes, both models should coexist under one policy framework.

Q: Why do AI agents complicate traditional IAM controls?

A: AI agents complicate traditional IAM controls because they do not behave like human users with short, predictable sessions. They can act continuously, chain actions, and reuse the same identity across many systems. That creates a governance problem centered on access duration, revocation, and blast radius, not just authentication.

Q: What do organisations get wrong when they standardise one authorization model for all agents?

A: They confuse consistency with control effectiveness. A single proxy model can create unnecessary inspection overhead, while a single token model can remove visibility where auditors need it most. The better approach is to map authorization design to application sensitivity, data handling requirements, and the level of forensic evidence the business expects.

Q: How do teams govern runtime access for agents without creating standing privilege?

A: Issue access as short-lived, task-scoped credentials and tie each grant to a specific policy decision. Then review token scope, lifetime, and revocation paths as part of identity governance, not as an afterthought. That keeps the agent’s authority narrow enough to limit blast radius if the session is abused.

Technical breakdown

Gateway authorization as a proxy control point

In the gateway model, every agent request passes through a policy enforcement layer before the application sees it. That layer validates identity, evaluates access policy, and can log the full transaction, including request intent and application response. Architecturally, this creates strong observability and makes it easier to answer forensic questions about what an agent did. The trade-off is that the proxy becomes part of the runtime path, so security and privacy both depend on trust in the intermediary.

Practical implication: Use a gateway when deep inspection, centralized enforcement, and transaction-level auditability are more important than direct-path privacy.

Token-based agent authorization and short-lived scope

The standards-based model described here issues short-lived, scoped tokens after identity verification, then lets the agent call the application directly. The key security property is that no standing key needs to persist beyond the token lifetime, which reduces exposure if the agent or surrounding environment is compromised. Because the token carries the permission boundary, the authorization decision is pushed into issuance time rather than mediated at every call. This is closer to workload-style identity governance than session proxying.

Practical implication: Use token-based authorization where latency, data privacy, and minimal standing credential exposure outweigh the need for full proxy inspection.

Why hybrid agent authorization is the realistic pattern

The article’s core point is that the two models solve different problems, so a single mechanism rarely fits all systems. High-sensitivity environments often need proxy-level inspection, while other applications need direct access and architectural privacy. In identity terms, this is a governance decision about where enforcement lives, how much telemetry you retain, and which systems justify real-time mediation versus tokenized autonomy. The architectural choice should follow the application risk profile, not the vendor’s preferred control plane.

Practical implication: Design policy so each agent and application pair is assigned the authorization model that matches its sensitivity, audit needs, and operational tolerance.

NHI Mgmt Group analysis

Agent authorization is now an NHI architecture decision, not just an API design choice. The article shows that runtime access for agents sits in the same governance family as service account and workload identity control, because the key question is where authority is expressed and how it is revoked. Once agents touch production systems, IAM teams have to treat authorisation as part of the identity lifecycle, not a one-off integration decision.

Gateway mediation and token issuance solve different trust problems, so forcing one pattern everywhere creates governance debt. Gateway models maximise visibility and enforcement, while short-lived tokens minimise standing credential exposure and reduce data-path intrusion. The mistake is to treat those as mutually exclusive when the real risk is mismatched control selection across environments. Practitioners should read this as a signal to classify applications by sensitivity before choosing an agent authorization pattern.

Short-lived scoped tokens represent an identity blast-radius control, but only when the token boundary is actually enforced. The security value comes from limiting how long an agent can act and how far it can move if compromised. That aligns with OWASP-NHI thinking around standing privilege reduction and with Zero Trust assumptions that access should be explicit, bounded, and continuously justified. The implication for teams is that token design must be evaluated as a governance boundary, not just a convenience feature.

Identity policy must become system-specific if agent governance is to scale. The article is right to reject the false binary between gateways and tokens. In mature programmes, the control objective is not standardisation for its own sake, but consistent assurance across different risk tiers, which means per-system policy, not one authorization architecture imposed across all AI agents.

Runtime auditability and data privacy are both valid security objectives, but they cannot be maximised simultaneously by the same control pattern in every case. Gateway designs privilege forensic completeness, while direct token designs privilege architectural privacy and lower credential persistence. That tension is now a central IAM design question for agentic systems, and it will shape how organisations separate experimental agents from production-grade agents. The practical conclusion is to formalise control selection criteria before agent sprawl hardens into policy drift.

From our research:

• Only 5.7% of organisations have full visibility into their service accounts, according to Ultimate Guide to NHIs.
• 71% of NHIs are not rotated within recommended time frames, increasing the risk of compromise over time.
• For lifecycle context, see Ultimate Guide to NHIs , Lifecycle Processes for Managing NHIs for the governance controls that determine whether runtime access stays bounded.

What this signals

Agent authorization is becoming a policy-selection problem, not a binary architecture decision. Teams that can classify systems by sensitivity and audit need will avoid over-rotating every agent through a gateway or leaving everything to token issuance. The useful control pattern is to separate high-observability use cases from low-latency, privacy-sensitive ones and govern both under one identity policy.

With only 5.7% of organisations having full visibility into their service accounts, according to the Ultimate Guide to NHIs, agent runtime authorization will expose the same visibility gap if teams do not design for it explicitly. The problem is not just access, but knowing which runtime path produced which action. That makes telemetry design part of identity architecture, not an optional logging exercise.

This is where Zero Trust language becomes operational. The most defensible agent programmes will treat every access pattern as conditional, measurable, and revocable, then document when a gateway is justified versus when a scoped token is enough. That distinction will matter more as agents move from experimentation into regulated production use.

For practitioners

• Classify agents by sensitivity tier Assign each agent and application pair to a sensitivity tier before choosing an authorization pattern. Use a gateway where full transaction inspection is required, and use short-lived tokens where direct access and data-path privacy matter more.
• Define when proxy mediation is mandatory Write policy that names the systems, data classes, and audit conditions that require a gateway in the path. This prevents teams from forcing every agent through one control plane or allowing exceptions without review.
• Treat token scope as a governance boundary Limit token permissions to the smallest practical action set and shortest viable lifetime. Review how token issuance maps to the agent’s operational task so the access grant matches the intended blast radius.
• Separate audit needs from privacy requirements Document which use cases need end-to-end interaction logs and which need the provider out of the data path. That distinction should drive architecture decisions, not vendor preference or team habit.
• Review agent authorisation as lifecycle governance Include agent authorization design in joiner-mover-leaver and access review processes so runtime authority is periodically revalidated. That keeps standing assumptions from hardening into permanent access patterns.

Key takeaways

• Agent authorization is an identity governance decision, not just a technical integration detail.
• Gateway and token-based models address different security objectives, so forcing one pattern everywhere creates avoidable governance debt.
• Runtime access for agents should be assigned by system sensitivity, audit need, and blast radius, not by vendor preference.

Key terms

• Gateway-based authorization: A pattern where access decisions are enforced at the network or API gateway rather than inside each application. For AI agents, this means the gateway becomes the checkpoint for model calls, tool discovery, and tool execution, with a separate policy engine deciding whether each request is allowed.
• Persistent Token: A persistent token is a credential that remains valid across sessions and can continue authorizing access until it is revoked or expires. These tokens are risky in AI and SaaS environments because they often outlive the original workflow and are hard to track consistently.
• Identity Blast Radius: The amount of damage a compromised identity can cause across systems, data, and infrastructure. In NHI environments, it is shaped by permissions, network reach, and administrative capability rather than by the credential alone. Reducing blast radius is a containment strategy that limits lateral movement and data exposure.

What's in the full article

C1.ai's full blog covers the operational detail this post intentionally leaves for the source:

• A side-by-side explanation of how the gateway and token models behave in real deployments
• The article's specific reasoning for when proxy mediation creates unacceptable data-path exposure
• Practical examples of how teams can choose an authorization pattern per system and per agent
• The vendor's own framing of the enterprise managed authorization standard and its implementation context

👉 C1.ai's full post covers the runtime trade-offs, privacy implications, and model selection guidance in more detail.

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity lifecycle are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are responsible for identity security strategy or NHI governance in your organisation, it is worth exploring.