Core concepts
Learn the deployment, environment, routing, cache, and observability terminology used by Easel.
Project
A project connects source code and platform configuration to a deployable application. It contains build settings, environment variables, domains, security controls, and deployment history.
Deployment
A deployment is an immutable version of an application built from a specific source revision and configuration. Every successful deployment receives a unique URL.
Environment
An environment selects the settings used to build and run a deployment. Easel currently distinguishes Preview and Production configuration.
An environment is not a long-running server and is not the same thing as a deployment.
Preview deployment
A Preview deployment is built with Preview configuration. Branch and pull-request URLs can move forward to the latest ready deployment associated with that source context.
Production deployment
A Production deployment is built with Production configuration. It may be assigned to production domains automatically or remain staged until promoted.
Current deployment
The Current deployment is the Production deployment receiving traffic for production domains. Promoting or rolling back changes this assignment without modifying the deployment itself.
Deployment URL
A deployment URL identifies one immutable deployment. Branch, pull-request, and production URLs are aliases that may point to different deployments over time.
Static asset
A static asset is a file produced by the build and served without application compute, such as HTML, JavaScript, CSS, fonts, and images.
Function
A Function runs server-side application code, including server-rendered routes, API handlers, loaders, actions, webhooks, and supported framework background work.
Request and invocation
A request is one HTTP exchange received by Easel. An invocation is an active Function execution session. One invocation may serve more than one request.
CDN cache
The CDN cache stores complete HTTP responses and is evaluated before a Function is invoked.
Runtime Cache
Runtime Cache stores application values accessed from Function code. It is separate from HTTP response caching.
Redirect and rewrite
A redirect returns a 3xx response that tells the client to request another URL. A rewrite changes the internal destination while preserving the browser-visible URL.
Region and edge location
An edge location receives and delivers requests. A compute region runs dynamic application code. These locations are not necessarily the same.
Request ID
A request ID uniquely identifies an Easel request and can be used to correlate response headers, request details, logs, traces, cache diagnostics, and security events.