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Module to execute warmup of the cache when app starts.


By default, the module is already included in @tramvai/module-server and no additional actions are needed.

import { createApp } from '@tramvai/core';
import { CacheWarmupModule } from '@tramvai/module-cache-warmup';

modules: [CacheWarmupModule],


Module is executed only when NODE_ENV === production.

  1. When app starts the module will request list of app urls from papi-route bundleInfo.
  2. For every url from the response it sends 2 requests: one for mobile and one for desktop device. But only 2 requests are running simultaneously in total.


In order to emulate mobile or desktop device next user-agent strings are used:

/** Chrome on Mac OS */
'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36',
/** Chrome on Mobile */
'Mozilla/5.0 (Linux; Android 7.0; SM-G930V Build/NRD90M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.125 Mobile Safari/537.36',


This module logs with id cache-warmup

How to

How to disable cache warmup?

Run application with env variable CACHE_WARMUP_DISABLED=true to prevent cache warmup in local or testing environments.