API Reference

/forms/{formId}/prefill

post
https://www.formstack.com/api/v2025/forms//prefill

Generate a prefilled form URL with specified field values

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Path Params
integer
required

The ID of the form

Body Params
string | null

Password for prefill

string | null

Internal use only. Used by Workflows (Copilot) to link form submissions back to workflow steps. Not applicable for standard API usage.

fields
array of objects

Array of field data to prefill with their values

fields
Responses

400

Invalid request body

403

Forbidden

404

Form not found

500

Unable to save prefill for form

Updated 4 months ago

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Response
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application/json

Updated 4 months ago