Best LLM API Gateways 2026
LLM gateways route, cache, and observe your model traffic. They're a critical layer — but a gateway is not a spend firewall. Here's the honest shortlist.
The shortlist
LiteLLM — the open-source proxy standard: routing, fallbacks, and budgets across 100+ providers.
Portkey — gateway plus observability and guardrails.
Cloudflare AI Gateway — global edge proxy with caching and rate limits.
OpenRouter — a single API across many models with usage analytics.
sipi.bot — not a gateway. A pre-spend decision layer that sits in front of any of them.
How to choose
Pick a gateway for routing and observability needs. The gateway decides where requests go; it doesn't decide whether a purchase may happen.
Rate limits cap requests, not dollars. A gateway-optimized retry loop can still spend $12,400.
The gap every list misses
None of the gateways enforce merchant allowlists, category budgets, or approval workflows on money-moving transactions. That's the firewall layer — and it composes with every gateway above.
At a glance
| Tool | Best at | Not for |
|---|---|---|
| LiteLLM | Open-source routing + budgets | Cross-merchant policy |
| Portkey | Gateway + guardrails | Pre-spend decisions |
| Cloudflare AI Gateway | Edge caching, rate limits | Dollar-level enforcement |
| OpenRouter | Multi-model single API | Payment approval |
| sipi.bot | Pre-spend enforcement | Traffic routing |
FAQ
Is a gateway enough for agent spend control?
No. Gateways manage request flow; they don't decide whether a transaction is within policy before it settles. You need both layers.
Can sipi.bot work with LiteLLM?
Yes — the common stack is sipi.bot → LiteLLM → provider. The firewall decides, the proxy routes.
Which gateway is best for agents?
It depends on your stack — LiteLLM is the open-source default, Cloudflare for edge, OpenRouter for multi-model simplicity. Add a firewall regardless.
Related
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