Add rich file preview support for PDF, Word, Excel, and more to your Retool app

This tutorial will show how to add our files component to your Retool app, enabling rich inline preview of virtually every file format. Have Retool ready, and let's get started.

1. Weavy API Key

First, we need an API key to communicate with the Weavy backend.

2. Authentication

We'll import this workflow, get the authenticated user in your Retool app, sync it with Weavy, and return an access token.

  • Download WeavyRetoolWorkflow.JSON (link below)
  • Go to Workflows in Retool
  • Click Create New and select From JSON
  • Choose to Upload a file in the modal and then Create workflow
  • All settings are already included, so all you have to do is Deploy (up to the right)
    • If the Deploy button is disabled, it's either already deployed (look for the text Latest version deployed), or some of the settings might not have loaded correctly - refresh, and it should be working.
    • Any message about no triggers configured can be ignored.
Download WeavyRetoolWorkflow.JSON

3. Get access token

Now, we'll put the workflow to work in your app to get an access token for the logged-in user.

Navigate to your app, go to Code in the left panel, to add a query, select Import Workflow

  • Name it getAccessToken
  • Select WeavyRetoolWorkflow from the Select Workflow dropdown
  • Change Workflow parameters to JSON and add values as below;
    • avatar: {{ current_user.profilePhotoUrl }}
    • email: {{ current_user.email }}
    • fullname: {{ current_user.fullName }}
    • uid: {{ current_user.sid }}
  • Expand Run behavior and select Automatic
  • Click Save & Run
  • If successful, you should see an access token in the output window



4. Add custom component

Search for Custom component in the components search bar.

Drag and drop it onto the canvas and do the following in the inspector:

For Content;

  • Remove all code in Model
  • Remove all code in IFrame Code

Check the following for Interaction;

  • Downloads
  • Forms
  • Modals
  • Popups
  • Fullscreen
  • Top-level navigation
  • Storage and cookies

5. Pass access token

This will trigger the workflow, return an access token, and pass it to the custom component. Update Model with;
Modify Model in the inspector - copy and paste this code
  "token" : {{ getAccessToken.data.access_token }}

6. Add the files view

In the IFrame code for the custom component, we'll initiate the Weavy context and pass the access token to the token factory for authentication.

Once authenticated, we can render the files component from Weavy.

Modify IFrame Code in the inspector - copy and paste this code
<script src="WEAVY_URL/uikit-web/weavy.js"></script>    
    const weavy = new Weavy();
    weavy.url = "WEAVY_URL";
    window.Retool.subscribe(function (model) {
      weavy.tokenFactory = model.token ? async (refresh) => model.token : undefined;

  :root { 
    --wy-theme-color: #3170F9; 
    font-family: "Inter var", sans-serif
  html, body { 
    padding: 0px; 

<div style="height:100%;display:flex;background:#fff">
    <wy-files uid="weavy-retool-files"></wy-files>
  • Line 6 - getting the access token from the workflow passed through the model.
  • Line 24 - rendering the files component.

7. Done!

The Custom Component with the Files component should load instantly - but toggle to Preview mode to see the full experience.

Note that this is fully working now and available for all your users if you want - rich file preview support added, just like that.


What's next?


Build workflow and custom component

A step-by-step guide to building a workflow and rendering a building block with the logged-in user.

The next step is to fetch the logged-in user of your Retool app, create a workflow to sync the user with Weavy and generate an access token so all of your users can start using our building blocks contextually.

Best way to learn step by step how it works

Import complete workflow and app

Use our JSON templates and import to quickly have it up and running to experiment.

We created a prebuilt workflow that fetches information about the current user in Retool, communicates with the Weavy API, and renders all our building blocks in an app.
The fastest way to get up and running with access tokens, etc.
Easy to extract to your own apps/modules