AI Gateway
Last Updated: September 10, 2026 | By Mihail Sebastian | AI Dictionary
A central proxy between applications and AI models or tools that enforces authentication, quotas, logging, and guardrails on every request that crosses it.
What is an AI Gateway?
An AI gateway is a central proxy that routes every request between an organization’s applications or agents and the AI models and tools they call, and enforces authentication, quotas, logging, and guardrails at that single point.
It is where policy meets traffic. A rule written in a document depends on people remembering it; a rule configured in the gateway applies to every request, whether or not anyone remembers.
How an AI Gateway Works
Applications send AI requests to the gateway instead of directly to a model provider or tool. The gateway authenticates the caller, checks the request against policy, applies guardrails such as blocking prompts that contain customer records, and meters usage against quotas.
Approved traffic goes through; everything is logged either way. Those logs are the raw material of agent observability: who called what, with which inputs, at what cost.
A gateway does more than block. It grants controlled, temporary access to a tool outside the approved registry, scoped and time-boxed, with extra logging attached. That turns a flat “no” into “yes, under watch,” which keeps teams from routing around governance entirely.
AI Gateway vs AI Registry
The gateway is the runtime checkpoint; the AI registry is the record of what the checkpoint should allow. One sits in the traffic path as infrastructure, the other is a policy artifact consulted by people.
They work as a pair: the registry decides, the gateway executes the decision on every request.
| Criterion | AI Gateway | AI Registry |
|---|---|---|
| Role | Enforcement of policy on live traffic | Record of what is approved and who owns it |
| When it acts | At request time, during use | At intake and review, before use |
| What it holds | Logs, quotas, credentials, guardrail rules | Owners, approval status, risk class |
| Without it | Rules exist on paper, nothing applies them | Nobody knows what AI is in use |
Example of an AI Gateway
A developer’s agent tries to call an external web-scraping API that is not in the registry. The request reaches the gateway, which checks the tool’s status and finds no approval.
Instead of failing the request outright, the gateway offers the sanctioned path: a 30-day scoped exception, limited to that agent, with every call logged, while the tool goes through registry intake. The developer keeps working; the security team gets a complete trace instead of a blind spot.
When the same agent later exceeds its token quota during a runaway loop, the gateway cuts the traffic at the limit. The incident costs one afternoon of debugging rather than an unbounded API bill.
Related AI terms: Guardrails · AI Registry · Agent Observability · Security · Shadow AI
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