🔮 Sanity Create is here. Writing is reinvented. Try now, no developer setup

Implementing a document type with automatic field population from an external API call.

3 replies
Last updated: Aug 18, 2022
I want to implement a document type so that users could fill one field and the rest of the fields would be populated automatically from an external api call based on that
I followed these docs to create a document action:
https://www.sanity.io/docs/document-actions This seems to support what I want to do, but I think using the publish button drop down menu is not the best UX. Ideally I would like something similar to the button that generates a slug based on the value of another field, so that the action would be close to where the editor has to input the item #. Is this passible with document actions? Or should I be doing this some other way?
Jul 5, 2022, 4:11 PM
You can also accomplish this with a custom input component. This is a very simple example component I made a while back that fetches from a specified url, then writes to another field in the document.

import React from 'react';
import { Card, TextInput, Button } from '@sanity/ui';
import { FormField } from '@sanity/base/components';
import PatchEvent, { set, unset } from '@sanity/form-builder/PatchEvent';
import { useId } from '@reach/auto-id';
import { withDocument } from 'part:@sanity/form-builder';
import { studioClient } from '../../lib/utils/studioClient';

const UrlWithButton = React.forwardRef((props, ref) => {
  const {
    type, // Schema information
    value, // Current field value
    readOnly, // Boolean if field is not editable
    markers, // Markers including validation rules
    presence, // Presence information for collaborative avatars
    compareValue, // Value to check for "edited" functionality
    onFocus, // Method to handle focus state
    onBlur, // Method to handle blur state
    onChange, // Method to handle patch events,
  } = props;

  // Creates a change handler for patching data
  const handleChange = React.useCallback(
    // useCallback will help with performance
    event => {
      const inputValue = event.currentTarget.value; // get current value
      // if the value exists, set the data, if not, unset the data
      onChange(PatchEvent.from(inputValue ? set(inputValue) : unset()));

  //Fetches the URL specfied then uses the JS client to write to the current document
  const handleClick = async () => {
    const res = await fetch(value).then(res => res.json());
        fetchObject: {
          fieldToWrite: res.data[3].breed,

  const inputId = useId();

  return (
      description={type.description} // Creates description from schema
      title={type.title} // Creates label from schema title
      __unstable_markers={markers} // Handles all markers including validation
      __unstable_presence={presence} // Handles presence avatars
      compareValue={compareValue} // Handles "edited" status
      inputId={inputId} // Allows the label to connect to the input field
      <Card padding={2}>
          id={inputId} // A unique ID for this input
          space={[3, 3, 4]}
          value={value} // Current field value
          readOnly={readOnly} // If "readOnly" is defined make this field read only
          onFocus={onFocus} // Handles focus events
          onBlur={onBlur} // Handles blur events
          onChange={handleChange} // A function to call when the input value changes
      <Card padding={2}>
export default withDocument(UrlWithButton);

Jul 6, 2022, 4:55 PM
user M
I just ran across this incidentally but what a cool use case.
Aug 17, 2022, 2:57 PM
user S
Aug 18, 2022, 4:06 PM

Sanity– build remarkable experiences at scale

Sanity is a modern headless CMS that treats content as data to power your digital business. Free to get started, and pay-as-you-go on all plans.

Was this answer helpful?