Frequently Asked Questions

Ignoring Routes

Ignore routes without config

I have a lot of routes I don't want Scully to handle.
How can I deal with this?

Scully will use the default plugin for any route that is not specified. When you want to have another way to handle defaults, you can replace this plugin with another one.
For example, if you want to ignore all undefined routes you can do:

registerPlugin('router', 'default', findPlugin('ignored'));

In case you want to have some more control, you can create a custom plugin:

  async (route: string): Promise<HandledRoute[]> => {
    if (route === 'somethingSpecial') {
      return [{ route, type: 'somethingElse' }];
    if (route === 'somethingSpecial/:id') {
      const data = httpGetJson('someEndPoint'); // fetch some json
      const { createPath } = routeSplit(route);
      const routes: HandledRoutes[] = [];
      for (const row of data) {
        routes.push({ route: createPath(, type: 'default' });
      return routes;
    return [];
  { replaceExistingPlugin: true }


How do I fix plugin build errors related to the `express-serve-static-core` module?

Building a plugin results in a fatal error Cannot find module 'express-serve-static-core', originating from node_modules/@scullyio/scully/lib/utils/serverstuff/staticServer.d.ts

To correct this, add the skipLibCheck and skipDefaultLibCheck flags to your tsconfig.json => compilerOptions like this:

  "compileOnSave": false,
  "compilerOptions": {
    "skipLibCheck": true,
    "skipDefaultLibCheck": true
Scully doesn't seem to find the plugins I just declared

Running scully gives a fatal error: Unknown type "myPlugin" in route "/aRoute"

I get this error:

you started scully outside of a scully project-folder,
or didn't install packages in this folder.
We can't find your local copy to start.
This can also happen on windows with PowerShell and mixed case path-names

This might happen when you started scully from within a different project, a subfolder that is too deeply nested. Or you are on Windows, using Powershell and have a uppercase character in your path. Scully will first try to start the local version, but if it can't find that, it errors out with this error. The solution is that you should start Scully inside the root of your project with:

npx scully

That will use the local version of scully, and should solve the issue.

Route Parameters

No configuration for route found

If you run Scully and the following warning is displayed, you need to teach Scully how to use the project's route parameters.

No configuration for route `/user/:userId` found. Skipping

The above error is given because Scully does not know all the possible values for :userId. Teach Scully how to get the list of :userIds from your app. Scully can turn /user/:userId into a list of meaningful pre-renderable routes like so:


Even small Angular projects have routes that contain route parameters. To stop Scully from skipping these routes, configure a route plugin. Route plugins teach Scully how to fetch data and merges it into routes using parameters.

The easiest way to understand route plugin is by understanding the jsonPlugin. It simply fetches data from any API that you specify, and it returns a list of properties that can be used to replace the route parameter. Checkout the jsonPlugin docs to see an example of how easy this configuration is.

Language params in routes

I have a routing structure which looks like this:
:lang can have few values ('it', 'en', etc.)
I prefer to store :lang in the config, without a dedicated endpoint.
How can I solve this?

As the Scully config file is typescript, you can post-process the routing object.
A very crude solution would be something like this:

import { ScullyConfig } from '@scullyio/scully';

const preLangConfig: ScullyConfig = {
  /** settings */
  routes: {
    ':lang/route1': { type: 'default' },
    ':lang/route2': { type: 'default' },
    ':lang/route3': { type: 'default' },
    ':lang/route4': { type: 'default' },
export const config = {
  routes: Object.fromEntries(
    // make sure you use a node-version that supports this, or use a reduce.
    Object.entries(preLangConfig.routes).reduce((all, [route, config]) => {
      if (route.includes(':lang')) {
        ['it', 'en', 'nl', 'sp'].forEach(
            lang // <-- language array
          ) => all.push([route.split(':lang').join(lang), config])
      } else {
        all.push([route, config]);
      return all;
    }, [])


It takes the preLangConfig and iterates over all the routes. When it finds the :lang parameter, it creates an entry with every value provided in the language array. That way the final config will have a route for every language available.

Docker and CI/CD

Using Scully inside Docker, GitLab, or other CI/CD environments > When I run Scully in XXX it gets stuck.

In all the cases we have seen around this, it is a problem with puppeteer running inside XXX. Most often it is missing the Chrome dependency. A lot of information about this is on the puppeteet troubleshooting page

We heard back from several users that a dockerfile like the below one works for them.

FROM node:12-alpine

RUN apk add --no-cache \
      chromium \


As a base docker config, and then make sure to set the environment correctly in the container that runs Scully: In order to use this I create my projects' Docker file like this:

FROM aboveConfig
ENV SCULLY_PUPPETEER_EXECUTABLE_PATH '/usr/bin/chromium-browser'
... more docker stuff here
... in the end:
RUN npx scully

Also, make sure you add the following to your config:

  puppeteerLaunchOptions: {
    args: ['--no-sandbox', '--disable-setuid--sandbox'],

File locations

Dist folder > Scully tells me I can't use the `dist` folder

As in some cases the Angular CLI puts the distribution files directly in the dist folder, and the Scully outputs its result in a subfolder of that by default. As most operating systems will raise objections if you are trying to copy a folder into a subfolder of that same folder. Scully will raise an error. To fix this error, you should open your angular.json and find the property outputhPath Then change that from:

  "architect": {
    "build" : {
      "outputPath": "dist",


  "architect": {
    "build" : {
      "outputPath": "dist/someName",

Scully Command Line Interface

Why are the pair of hyphens - `--` - used when running `npm run Scully`?

The pair of hyphens i.e. -- indicates to node js that this is the end of node options and every option after that should be passed to the script being run, in this case Scully.