Gateways and Governance Are Not the Same Layer
AI gateways solve a real infrastructure problem: routing requests across multiple model providers, caching responses, load balancing, and tracking token cost and usage. These are proxy-layer functions, and they are valuable on their own. Governance is a separate architectural requirement. It concerns whether a system can evaluate a request against a defined policy at the moment it is about to execute, and whether it can deny that request in real time rather than simply logging it afterward.
A platform can be an excellent gateway and still provide no runtime enforcement, no agent-level identity, and no least-privilege tool-call authorization. When evaluating Portkey, LiteLLM, or any similar platform, the first question is not what the dashboard shows, but whether the system can stop a non-compliant action before it happens.
Agent Identity and Least-Privilege Tool-Call Authorization
As AI systems move from single-turn completions to agents that call tools, query databases, and invoke other agents through protocols like MCP, the access-control question changes. A traditional API proxy model assumes one trusted caller operating under one API key. Multi-agent and MCP-based architectures introduce multiple semi-autonomous callers with different privilege requirements.
Genuine agent identity means each agent receives a distinct, verifiable credential, separate from the human or service account that deployed it, with permissions that can be scoped, rotated, and revoked independently. Least-privilege tool-call authorization means an agent can only invoke the specific tools and functions it has been explicitly granted, rather than inheriting blanket access tied to an underlying API key. Architects should determine whether a platform treats agent identity as a first-class construct or whether agents simply operate under the credentials of whatever key initiated the session.
Governance Criteria Across Gateway and Governance-Layer Architectures
The two categories address different points in the request lifecycle. The table below separates functions typically handled by a gateway or proxy from functions that belong to a runtime governance layer.
| Function | What it covers |
|---|---|
| Routing & caching | Request forwarding, load balancing, and cost tracking across model providers. |
| Runtime policy enforcement | Evaluating and blocking non-compliant tool calls at execution time. |
| Agent identity | Distinct, scoped credentials assigned to agents rather than shared API keys. |
| Auditability | Tamper-evident records of which policy rule permitted or denied an action. |
What Auditability Actually Requires
Logging is not auditability. A record showing that a request was sent and a response was returned confirms that a call happened, but it does not establish whether that call was authorized, under what rule, or by whom.
Genuine auditability in a governance context means producing tamper-evident, queryable records that capture the specific policy decision applied to each tool call: which rule permitted or denied it, which agent identity initiated it, and what scope of access was in effect at the time. This distinction matters directly for compliance review. An internal or external auditor asking whether least-privilege access controls are enforced needs evidence of a decision, not just evidence of traffic. Architects should confirm whether a platform's logs would hold up as evidence of policy enforcement, or whether they only demonstrate that the proxy layer was functioning.
Where Trussed AI Fits
Trussed AI is built as a runtime governance and security layer for enterprise AI agents, rather than as a routing or caching proxy. Its scope covers runtime policy enforcement, agent identity, least-privilege permissioning, tool approval workflows, MCP security, and audit logging tied to specific policy decisions.
This positions it to address the governance gaps described above: enforcing decisions at execution time, assigning agents distinct identities rather than shared keys, and producing audit records that document which rule applied to a given tool call. Organizations already using a gateway for routing and cost tracking do not necessarily need to replace it. The relevant question is whether that gateway also enforces policy and identity at the agent level, or whether a dedicated runtime governance layer is needed to close that gap before agents are granted broader tool-calling capabilities.