Model routing with Google Cloud API Gateway

Summary

Google Cloud API Gateway adds model routing in Public Preview for AI applications that need to direct traffic among models without hardcoded endpoints or open-source proxies. The serverless ingress layer accepts OpenAI-compatible requests and uses routing rules in an OpenAPI 3.x specification, where x-google-api-management defines backends and routers map virtual model names to targets such as Gemini, Claude, or OpenAI OSS-GPT. After deployment, clients call a stable endpoint; the Gateway transcodes the request to the backend’s native schema, adds an Agent Platform authentication token, and forwards it, separating client authentication from provider credentials. The guide also notes that every backend in one router must share a host, and shows standalone routing alongside possible Agent Gateway integration for security governance.

Takeaways

1. 1

   Model routers map virtual model names to Gemini, Claude, or OpenAI OSS-GPT targets through OpenAPI configuration, with separate example routers for Gemini-Claude and OpenAI-Gemini.

2. 2

   All backends referenced by a single router must share the same host; routing changes the model and path on that host rather than routing across different hosts.

3. 3

   Applications use one stable Gateway endpoint and authenticate with an API key, while the Gateway handles native backend schemas and Agent Platform authentication.