8 LLM Gateways APIs

LLM Gateways APIs let you add llm gateways capabilities without building from scratch. Every entry below is profiled with trust signals — pricing model, authentication requirements, CORS support, rate limits, and live uptime checks — so you can compare options and pick production-safe choices instead of guessing from a link list.

llm routingai gatewaysmodel proxyobservabilityfallbacksinference
APIPricingAuthCORSHealth
Cloudflare AI Gateway API
AI application control-plane API for model routing, caching, observability, analytics, and provider management.
FreemiumAPI KeyNoProfile
Helicone AI Gateway API
OpenAI-compatible AI gateway and observability API for routing, logging, caching, analytics, and model usage tracking.
FreemiumAPI KeyNoProfile
LangDB AI Gateway API
OpenAI-compatible AI gateway API with model routing, thread management, analytics, and multi-provider access.
FreemiumAPI KeyNoProfile
LiteLLM Proxy API
OpenAI-compatible LLM proxy and gateway for routing requests across many model providers from one API surface.
Open SourceAPI KeyUnknownProfile
OpenRouter API
Access and route requests across many AI models and providers through one OpenAI-compatible API.
FreemiumAPI KeyYesProfile
Portkey AI Gateway API
Universal AI gateway API for routing, fallbacks, caching, guardrails, and observability across major model providers.
FreemiumAPI KeyNoProfile
Requesty AI Router API
OpenAI-compatible AI router for using many model providers with failover, load balancing, budgets, and team controls.
FreemiumAPI KeyNoProfile
Vercel AI Gateway API
Unified AI model gateway for accessing many providers through AI SDK, OpenAI-compatible, Anthropic, and Responses-style APIs.
FreemiumAPI KeyNoProfile

How to choose a llm gateways API

Start with pricing and auth: free tiers and no-auth APIs are fastest to prototype with. Then check CORS if your app calls the API from the browser, and health before you commit — a great API that's been down for a week will block your launch. Each profile below shows all of these signals plus rate limits where documented.