What is an AI gateway?
Last updated 2026-08-19
An AI gateway is a service that sits between your application and model providers, giving you one endpoint and one key surface for many models, with controls the raw provider APIs do not offer: rate and spend caps, failover, usage visibility, and sometimes routing. Every gateway does the traffic plumbing. The evaluation question is what the gateway is accountable for: access products are done when the request goes through, and optimization gateways like Finest are priced on whether the bill actually went down.
What every gateway gives you
One integration instead of one per provider. Keys your team can issue and revoke without touching provider consoles. Caps that stop a runaway loop at a number you chose. A usage surface finance can read. Failover when a provider degrades. This layer is real, it is table stakes, and most products in the category do it competently.
The divide: access or outcomes
Access gateways monetize the pipe: a platform fee, a percentage on credits, or a subscription, owed whether or not the gateway improved your economics. Optimization gateways monetize the result. Finest is the strict version of the latter: tokens at the host's published rate with no markup, substitutions only under sealed published evidence per task class with your requested model as the verbatim default, and a fee of 25% of the saving proven on each request's receipt.
Neither model is dishonest. But they answer differently the one question worth asking before production traffic flows: what does this vendor earn when my bill does not improve. For an access product, the same as always. For Finest, nothing.
A short evaluation checklist
- Fee shape
- Markup, platform fee, subscription, or contingent on savings. Get it in one sentence.
- Default behavior
- What happens to a request the gateway has no opinion about. The safe answer is: exactly what you asked for.
- Proof
- Per-request evidence of what ran and what it cost against your intended model, not a monthly dashboard.
- Exit
- How many lines of code to leave. On Finest, FINEST_DISABLE=1 is one.
Questions people ask
- Do I need an AI gateway?
- Once more than one team, key, or model touches production, the plumbing alone pays for itself: caps, key hygiene, and visibility. Whether you also want optimization depends on whether the bill is a problem someone owns.
- Does an AI gateway add latency?
- A gateway adds a network hop. Whether that is measurable depends on the deployment, and it is the right measurement to run in your own region. What a gateway must never add is silent behavior change, which is why the requested-model-verbatim default matters.
- Is Finest an AI gateway?
- Yes: OpenAI-compatible and Anthropic-compatible endpoints, keys, caps, and visibility, plus the part most gateways do not price: evidence-bound optimization with a fee only on proven savings.
In 2 minutes, start cutting your API spend without sacrificing quality. Free if you don’t save money.
No model markup. You pay the host’s rate. 25% of what it proves it saved on a request. No saving, no fee.