Google Cloud API Gateway

What Google Cloud API Gateway is

Google Cloud API Gateway provides a managed entry point for backend services, giving them a consistent REST API regardless of how the services are implemented. It handles API hosting, logging, monitoring, and security, and integrates with Google Cloud for traffic management, authorization, and monitoring concurrent API calls. Supported authentication options include API keys, Google authentication methods, Google ID tokens, and service accounts or JWT.

The gateway accepts OpenAPI 2.0 and OpenAPI 3.0 specifications, including all OpenAPI 3.0 patch versions. Documented backend integrations include Cloud Run, Cloud Run functions, and App Engine. It supports HTTP/REST, HTTP/JSON, and gRPC, along with request transformation and rate limiting. Logs capture request and response information, while monitoring tracks latency, traffic, and errors.

Documented limits include 50 APIs total, 100 API configurations per API, and 50 gateways per region. Request and response payloads can be up to 32 megabytes, except for gRPC transcoding, which is limited to 1 megabyte. New security settings enforce TLS 1.2 or later. Public Preview features include MCP support for making existing REST APIs available as tools to AI agents, and model routing for OpenAI-compatible prompts to models in Model Garden. Pricing is listed by API-call volume, including $3.00 per month for the 2M–1B calls tier and $1.50 per month for the 1B+ tier.

Who it suits

Google Cloud API Gateway suits developers and organizations that need a managed, secure API layer for backend services, particularly services using Cloud Run, Cloud Run functions, or App Engine. It also fits teams that need API traffic visibility, rate limiting, or OpenAPI-based configuration.

Limits

The documented service limits are 50 APIs total, 100 API configurations per API, and 50 gateways per region. Requests and responses are limited to 32 megabytes, with gRPC transcoding limited to 1 megabyte; the monthly request limit is 1,000,000,000 requests.

Getting started

1. Visit the Google Cloud API Gateway website.
2. Prepare an OpenAPI 2.0 or OpenAPI 3.0 specification.
3. Connect a documented backend such as Cloud Run, Cloud Run functions, or App Engine.
4. Choose authentication options such as API keys, Google authentication, Google ID tokens, or service accounts/JWT.
5. Configure traffic controls and monitoring for the API.

Verdict

Choose Google Cloud API Gateway when you need a managed API layer for supported backends, with authentication, traffic controls, and request monitoring. Look elsewhere if you need it to proxy to Google Cloud APIs such as BigQuery APIs, or if your gRPC transcoding payloads exceed 1 megabyte.