Prefill

Create a prefill, then send the prefill blob directly to your own storage by PUTting it to the url in the returned upload object with its headers. The blob is a JSON document of shape { "fields": [{ "id": "<field id>", "value": "<value>" }] }. Each id is a field id from GET /documents/{document_id}/fields; each value is a string for text and checkbox fields, a base64 data URL (for example data:image/png;base64,...) for signature and picture fields, or one of the listed options when the field is constrained. Signatures look best as a transparent PNG at roughly a 3:1 aspect ratio (for example 1200x400). Unknown ids are ignored and read-only fields ignore prefill values. Returns an embed_url a recipient opens to review and submit. Requires your own storage (S3, Azure Blob Storage, or SharePoint) that allows read access (write-only storage cannot serve the blob back to recipients) and a document with configured fields.

post/documents/{document_id}/prefills

Request

  • Base URL: https://api-docs.simplepdf.com/api/v1
  • URL: https://api-docs.simplepdf.com/api/v1/documents/{document_id}/prefills
  • Auth: HTTP bearer

Path parameters

document_idstring uuid required

Request body

contextobject nullable

Optional correlation metadata delivered inline to the submission webhook. Do NOT put sensitive information here. PII belongs in the prefill blob (customer storage).

Example request

{
  "context": {
    "agent": "intake-bot",
    "user_id": "u_123",
    "environment": "production"
  }
}

Response

Successful response

idstring required
created_atstring required
embed_urlstring required

Link a recipient opens to review and submit the prefilled document (standalone or embedded).

Example response

{
  "id": "05666d45-96d0-42ce-b24b-f1f1af228f57",
  "created_at": "2026-03-21T10:00:00.000Z",
  "upload": {
    "url": "https://customeraccount.blob.core.windows.net/prefills/...?sv=...&sig=...",
    "headers": {
      "Content-Type": "application/json",
      "x-ms-blob-type": "BlockBlob"
    }
  },
  "embed_url": "https://api-docs.simplepdf.com/documents/05666d45-96d0-42ce-b24b-f1f1af228f57?prefill=..."
}

Changes

No recorded changes to this operation across all 1 revision of this API.