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24K Labs PDF AcroForm Filler
x402
24K Labs PDF AcroForm Filler is a paid API for AI agents from api.24klabs.ai, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-14).
Fills AcroForm text field values in a base64-encoded PDF and returns the completed PDF as base64, reporting which fields were set.
Price / call$0.006
Success—
StatusUnknown
How this service works
Fill AcroForm text field values in a base64-encoded PDF and return the finished PDF as base64. Reports which fields were set. Optionally sets NeedAppearances for viewer rendering.
Output
Returns the completed PDF as a base64-encoded string, along with a report of which AcroForm text fields were successfully set. Indicates whether NeedAppearances was applied for correct rendering across PDF viewers.
Example use cases
Automated contract form completion
“I have a base64-encoded NDA PDF with AcroForm fields — fill in 'PartyName' with 'Acme Corp', 'EffectiveDate' with '2025-07-01', and 'Jurisdiction' with 'California', then give me the filled PDF back as base64.”
Government application form auto-fill
“Take this base64 PDF of a visa application form and populate the fields 'ApplicantName', 'PassportNumber', and 'DateOfBirth' with 'Maria Santos', 'X1234567', and '1990-03-15' respectively — return the completed form as base64 with NeedAppearances set to true.”
Invoice template population
“Here's an invoice template PDF encoded in base64 — fill the AcroForm fields 'InvoiceNumber' with 'INV-2025-004', 'ClientName' with 'Bright Ideas LLC', and 'TotalAmount' with '$4,750.00', and send me back the finished PDF as base64.”
Technical details
Endpoint
POSThttps://api.24klabs.ai/api/v1/pdf-form-fillWhen to prefer
Choose this endpoint when you need to programmatically fill AcroForm text fields in an existing PDF and receive the completed document as base64 — ideal for automating document workflows, contract completion, or form submissions without a PDF rendering library. Prefer this over general-purpose PDF tools if you specifically need AcroForm field targeting with per-field fill reporting and NeedAppearances control.
Side effects
- Invalid or malformed base64 input — returns error indicating decode failure
- PDF does not contain AcroForm fields — no fields set, report will be empty
- Field names not found in the PDF — fields silently skipped or reported as unset
- Corrupted or encrypted PDF — processing fails with an error
- Oversized PDF payload — may exceed request limits and return a size error
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| fields | object | |
| pdf_b64 | string |
Output
Schema · Response
{
"type": "json",
"example": {
"pdf_b64": "...",
"filled_fields": [
"Name"
]
}
}Tags
x402
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