The control fails because each gateway answers a different question. Content security checks the prompt, routing checks the connection, and runtime authorization checks whether the agent is allowed to perform the action. If identity is not evaluated at execution time, an agent can pass every upstream check and still complete an unauthorised business action.
Why This Matters for Security Teams
One AI gateway can be useful for centralising traffic, but it cannot safely collapse three different security questions into one decision point. Content filtering looks at what was said, routing looks at where the request goes, and access control must decide whether the identity behind the request can actually perform the action. That distinction matters because agentic systems are goal-driven, can chain tools, and can pivot from a harmless prompt into an unsafe business action if runtime authorization is missing.
Security teams often inherit gateway-centric designs because they appear to simplify governance, yet the simplification is mostly cosmetic. A gateway that only inspects prompts or tokens does not understand task intent, approval context, or the privileges implied by downstream tool calls. Guidance from the OWASP Non-Human Identity Top 10 and NHIMG’s Ultimate Guide to NHIs both point to the same operational issue: identity and authorization must be handled where the action occurs, not only where the request enters.
In practice, many security teams encounter unauthorised tool use only after an agent has already routed through the “approved” gateway and executed the wrong business action.
How It Works in Practice
A safer pattern separates content security, routing, and authorization into distinct controls. The gateway can still inspect prompts, redact obvious secrets, and route traffic, but it should not be treated as the final authority for whether an agent may read a record, send a message, approve a payment, or invoke a privileged API. That decision belongs to runtime policy evaluated against the actual workload identity, the requested action, and current context.
For autonomous systems, the identity primitive should be the workload itself, not a human session borrowed at login time. Current practice increasingly relies on cryptographic workload identity such as SPIFFE/SPIRE or short-lived OIDC tokens, paired with policy-as-code so authorization can be evaluated at request time. NIST’s SP 800-53 Rev 5 supports the broader control model, while the LLMjacking research shows why static credentials are dangerous when attackers can move from exposed secrets to active abuse in minutes.
- Use the gateway for content inspection and safe routing, not as the final authorization engine.
- Issue just-in-time, short-lived credentials per task, then revoke them automatically when the task ends.
- Evaluate policy at execution time using action, identity, data sensitivity, and approval state.
- Log tool calls separately so security teams can see what the agent actually did, not just what it asked for.
The operational goal is simple: a prompt may be allowed, but the downstream action still needs a separate decision that can fail closed. This approach aligns with NHIMG’s analysis in The State of Secrets in AppSec, where fragmented secret handling shows how quickly centralised control breaks down when identities and credentials are not tightly scoped. These controls tend to break down in multi-tool agent meshes because chained actions create more decision points than a single gateway can reliably govern.
Common Variations and Edge Cases
Tighter gateway control often increases latency and operational overhead, requiring organisations to balance faster developer workflows against stronger execution-time enforcement. That tradeoff is real, especially in environments where teams want one platform for prompt filtering, DLP, and policy enforcement. Current guidance suggests those functions can coexist, but they should not be conflated into one trust decision because the failure modes are different.
There is no universal standard for this yet, but best practice is evolving toward layered controls: gateway inspection for content risk, workload identity for provenance, and real-time policy evaluation for authorization. This matters most when agents can call external tools, chain requests, or act across systems with different privilege domains. NHIMG’s 52 NHI Breaches Analysis and Replit AI Tool Database Deletion both show how quickly automation can turn a small permission gap into a material incident.
The edge case that repeatedly surprises teams is shadow automation: an agent uses an approved gateway but later invokes tools through a different path, different token, or different environment boundary. In those setups, gateway-only controls create a false sense of safety because the access decision was never bound to the action itself.
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, CSA MAESTRO and OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST AI RMF and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | A2 | Addresses agent autonomy and tool abuse when one gateway is trusted too broadly. |
| CSA MAESTRO | T1 | Covers trust boundaries for agent workflows and execution-time governance. |
| NIST AI RMF | Supports governance for AI systems whose actions change with context and runtime state. | |
| OWASP Non-Human Identity Top 10 | NHI-01 | Gateway-only designs fail when non-human identities are not governed at execution time. |
| NIST CSF 2.0 | PR.AC-4 | Least privilege and access management are directly implicated by gateway-only authorization. |
Bind each agent action to runtime policy and deny tool use unless intent and identity are verified.
Related resources from NHI Mgmt Group
- What breaks when organisations rely on NLA as their main access control?
- What breaks when organisations rely on periodic access reviews for AI systems?
- What breaks when organisations rely on traditional file access logs for AI-assisted work?
- What breaks when security teams rely on content guardrails to control AI agents?