Glossary

This page provides brief definitions and links to more information of terms that are used in the Cloud Endpoints documentation.

API key: A code passed in by a client application when it calls an API. API keys identify the application or the Google Cloud project making the call to the API. See Why and when to use API keys for more information on using an API key with your Endpoints API.
Auth0: A service that lets you define how users authenticate to applications. See Auth0 for more information.
Cloud Endpoints Frameworks: Endpoints Frameworks for the App Engine standard environment consists of tools, libraries, and capabilities that let you generate APIs and client libraries from an App Engine application. See About Endpoints Frameworks for more information.
container: A software package that contains the libraries, frameworks, and settings. that an application requires to run. See What is a container for more information.
CORS: Cross-Origin Resource Sharing (CORS) is a specification that provides a way for web applications to access resources on a server in another domain (technically, in another origin). To learn more about CORS, see the Mozilla Developer Network (MDN) web docs and the Fetch Living Standard.
Docker: Open source software that lets you automate deploying applications inside software containers. See What is Docker for more information.
Extensible Service Proxy: The Extensible Service Proxy (ESP) is an Nginx-based high-performance, scalable proxy that runs in front of an OpenAPI or gRPC API backend and provides API management features such as authentication, monitoring, and logging. See About Endpoints and Endpoints: Architectural overview for more information.
Extensible Service Proxy V2: The Extensible Service Proxy V2 (ESPv2) is an Envoy-based high-performance, scalable proxy that runs in front of an OpenAPI or gRPC API backend and provides API management features such as authentication, monitoring, and logging. See About Endpoints and Endpoints: Architectural overview for more information.; ESPv2 supports version 2 of the OpenAPI Specification and gRPC Specifications.
Firebase authentication: Google's authentication service that supports end user sign-in for client applications by using credentials from popular federated identity providers such as Google, Facebook, or Twitter. See Firebase authentication for more information.
Google ID token: A JSON Web Token (JWT) that contains the OpenID Connect fields needed to identify a Google user account or service account, and that is signed by Google's authentication service, https://accounts.google.com.
gRPC: A high performance, open source universal RPC framework developed by Google. In gRPC, a client application can directly call methods on a server application on a different machine as if it was a local object. See Cloud Endpoints for gRPC APIs for information on using gRPC with Endpoints and the gRPC website for general information.
JWT: JSON Web Token is an open standard access token format for use in HTTP Authorization headers and URI query parameters. See Introduction to JSON Web Tokens for general information.
kubectl: A command-line interface for running commands against Kubernetes clusters. You use kubectl when deploying an API for Endpoints on a Kubernetes or Google Kubernetes Engine cluster. See Overview of kubectl for more information.
Kubernetes: Open source software that lets you automate the deployment, management, and scaling of containerized applications across clusters of hosts. See Kubernetes for more information.
NGINX: An open source, high-performance HTTP server and service proxy that ESP is based on. See the NGINX Wiki for more information. For information on ESP, see About Cloud Endpoints and Endpoints: Architectural overview.
OpenAPI: The Open API Initiative is an industry-wide effort to standardize the description of REST APIs. APIs that are described with the OpenAPI Specification (formerly the Swagger Specification) can be supported with common tools that create documentation, automate testing, and generate code for clients and servers. See OpenAPI overview for more information.
OpenAPI document: A configuration file in either YAML or JSON format that you use to describe your API.
surface: The public interface of an API. An API's surface consists of the methods as well as the parameters and return types used in the methods.