How Does an LLM Gateway Work? A Practical Guide for Engineering Teams
Perplexity, Tuesday, October 27th, 2026
Perplexity explains how an LLM gateway routes, secures, caches, and logs model calls, and compares build, self-host, and managed options.
An LLM gateway is a reverse proxy between applications and model providers that handles credentials, routing, caching, and logging.
The guide walks a request through authentication, policy checks, cache lookup, routing with fallback, provider translation, and usage and cost logging.
It warns that gateways concentrate secrets, citing LiteLLM vulnerabilities fixed in version 1.83.9, and are a single point of failure, citing a June 2025 Cloudflare AI Gateway outage.
It compares building in-house, self-hosting open-source tools like LiteLLM, managed services like OpenRouter, and extending API gateways such as Kong or Azure API Management.