meeko preview

meeko preview starts the production build with its adapter's runtime to check that what you will deploy works: it compiles nothing, so first run meeko build with the same adapter.

Usage#

meeko build --adapter static
meeko preview --adapter static

http://localhost:4173

Type#

meeko preview [directorio] [--adapter <node|cloudflare|bun|deno|static>]

Options#

Result#

• Node and static print the URL and serve in this process until Ctrl+C. As with meeko start, loopback and 0.0.0.0 are displayed as http://localhost:4173 and, with 0.0.0.0 or ::, Red: lines follow with network addresses. Bun and Deno outputs print the same; Deno only lists the network with --allow-sys=networkInterfaces, included in -A.
• Bun, Deno and Cloudflare inherit the child process's console, which writes its own output; meeko preview forwards SIGINT and SIGTERM to it and exits with the child's exit code.
• static serves the requested file, the folder's index.html or 404.html with status 404 (or Not Found if the build has no 404.html, because app/error.meeko is missing), without exposing _headers or _meeko/, and applies contentSecurityPolicy and headers as hosting would with headerFiles. Only accepts GET and HEAD (another method gives 405 with Allow: GET, HEAD) and everything carries cache-control: no-cache.

Examples#

A static site before uploading#

meeko build --adapter static
MEEKO_PORT=5000 meeko preview --adapter static

curl -sI http://127.0.0.1:5000/
# HTTP/1.1 200 OK
# content-type: text/html; charset=utf-8
# cache-control: no-cache
curl -s -o /dev/null -w "%{http_code}\n" http://127.0.0.1:5000/no-existe
# 404

Bun or Deno#

meeko build --adapter bun
meeko preview --adapter bun

The build already contains all dependencies: what works here works by copying only .meeko/output/bun/ to the server. With Deno, preview grants all permissions (-A); in production, --allow-net, --allow-env and --allow-read for the folder suffice.

Cloudflare Workers locally#

pnpm add -D wrangler
meeko build --adapter cloudflare
MEEKO_PORT=8787 meeko preview --adapter cloudflare

preview uses the application's Wrangler or, if absent, the one from the Meeko installation.

The configured adapter#

With server: { adapter: "deno" } in meeko.config.ts, neither command needs --adapter:

meeko build
meeko preview

Common mistakes#

Preview a different adapter from the one built#

meeko build --adapter static
meeko preview

Without --adapter, preview takes the configured adapter (default node) and looks for another build: No hay build de producción en …\.meeko\output\node\index.mjs; ejecuta meeko build. For other adapters the message names their file, such as No hay build de producción en …\.meeko\output\deno\main.js; ejecuta meeko build --adapter deno or No hay build estático en …\.meeko\output\static; ejecuta meeko build --adapter static.

meeko build --adapter static
meeko preview --adapter static

Cloudflare without Wrangler#

meeko build --adapter cloudflare
meeko preview --adapter cloudflare

If neither the application nor Meeko finds Wrangler: Wrangler no está instalado; añádelo con pnpm add -D wrangler para previsualizar el build de cloudflare.

pnpm add -D wrangler
meeko preview --adapter cloudflare

--adapter without a name#

meeko preview --adapter

Falta el nombre del adaptador en --adapter de preview, with usage information and exit code 1. An unknown name gives Adaptador desconocido: …; usa node, cloudflare, deno, bun o static.

meeko preview --adapter bun

Notes#

• For testing, not production. With Node, preview and start are the same server; with static, the preview server only imitates hosting and must not be exposed to the Internet. With Deno, -A grants more permissions than required.
• Runtimes. bun and deno must be in PATH. If the executable is missing, the error is Bun no está instalado o no está en el PATH; instálalo desde https://bun.sh para previsualizar el build de bun (or the Deno equivalent). A version manager with shims, such as mise or asdf, may intercept the command and display its own error.
• Windows and POSIX. The child process launches without its own window on Windows, using the parent's console, and receives forwarded SIGINT and SIGTERM. If the child terminates due to a signal, preview exits with code 1.
• Sessions. With Node, Bun and Deno, preview runs in production mode: it needs MEEKO_REDIS_URL or sessions in server/runtime.ts, like meeko start.
• CSP. preview applies server.contentSecurityPolicy and server.headers just as production does (with static since 1.3; with server adapters since 1.7). Check here that CSP does not block anything before deployment.

Related#

• meeko buildChecks the project and writes production output to .meeko/output/<adaptador>/, including the client, server and prerendered pages.
• meeko startStarts the Node production server using meeko build output, without Vite or application sources.
• createBunServerThe fetch and websocket handlers for serving a Meeko application with Bun.serve, using Bun's native WebSocket for Socket and its payload, backpressure and idle limits.
• serveDenoServes a Meeko application with Deno.serve, with Socket over Deno.upgradeWebSocket, graceful shutdown on signals and the process failure policy.
• createWorkerServes a Meeko application from a Cloudflare module Worker, created once per isolate with its bindings, forwarding Socket upgrades to their room's Durable Object.
• Static siteMeeko as a full-stack framework
• BunMeeko as a full-stack framework
• DenoMeeko as a full-stack framework
• Cloudflare WorkersMeeko as a full-stack framework