External REST Data Source
Professional & EnterpriseThe Dropdown list and Autocomplete search box options on plain-text fields (single-line and multiline) can now be driven by an external REST endpoint instead of a SharePoint list. This lets you populate field choices from any HTTP GET API reachable from the browser.
1. Choosing the data source
In the field’s Dropdown list / Autocomplete configuration, a Data source toggle switches between:
- SharePoint list — the existing behavior, unchanged.
- REST endpoint — the new option, described below.
The rendered control is the same either way: a ComboBox for Dropdown list, a TagPicker for Autocomplete search box.
2. REST endpoint settings
| Setting | Description |
|---|---|
| Endpoint URL | Any HTTP GET endpoint. Supports [[fieldValue:FieldName]] and [[variable:VarName]] tokens, so the URL can include values from other fields or global variables (enables dynamic filtering). |
| Authentication | None, Bearer token, or API key header. The token/key value also supports tokens for dynamic substitution. |
| Path to array in response | Dot-notation path to the array inside the JSON response (e.g. value for OData, data.items for a custom API). Leave blank if the response root is already an array. |
| Display property name | The property on each response object used as the option label and stored value (the REST equivalent of “Fieldinternalname” in SharePoint mode). |
All the shared options still apply: Additional search fields, Sort by, Placeholder, Set field value (cascading updates), and Autofill if only one option.
3. Examples
OData-style endpoint
- Endpoint URL:
https://api.contoso.com/odata/Departments - Path to array in response:
value - Display property name:
Name
Response shape:
{ "value": [ { "Id": 1, "Name": "Finance" }, { "Id": 2, "Name": "HR" } ] }Custom API with nested array and dynamic filter
- Endpoint URL:
https://api.contoso.com/products?category=[[fieldValue:Category]] - Path to array in response:
data.items - Display property name:
title - Authentication: Bearer token →
[[variable:apiToken]]
As the user changes the Category field, the endpoint URL re-resolves and the product list updates.
4. Tips
- The endpoint must be CORS-accessible from the SharePoint origin and reachable from the user’s browser — these calls happen client-side.
- Keep secrets out of forms. If you must use a token, prefer a global variable populated at runtime over hard-coding a key in the configuration.
- Use Additional search fields so users can match on more than just the display property when typing in the autocomplete box.
- Combine with Set field value to cascade: selecting a value from the REST list can auto-fill related fields on the form.