Bug: External libraries (chroma.js) and preloaded js not loading in Retool Mobile

I've added chroma.js as a Library under App Settings. It works fine in the editor and in user mode. However, in the mobile app, any transformer that uses the library will return undefined. Same goes for Preloaded JS functions.


  • Retool Mobile v3.66.0 version number 2339
  • Google Pixel 8 running Android version 14
  • Out-of-the-box libraries (moment, lodash, numbro) work fine
  • Retool Mobile console error: "[functionName] is not defined"

I tried a basic mobile app and imported the chroma.js file you linked above and was able to get it working (in both the editor + the mobile app) with a transformer like:

const color = {{ textInput1.value }}

return chroma(color).darken().hex()

By any chance could you share your transformer code?

I went so far as to create a single transformer to test libraries one by one. When I included:

let color = chroma('white').hex()

in the transformer, that killed the app. The mobile console error was 'chroma is not defined'

Just to confirm, this is what the Libraries section looks like for you?