# 24K Labs PDF Form Fill

> 24K Labs PDF Form Fill is a paid API for AI agents from api.24klabs.ai, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-13).

Fills a PDF form with provided field values and returns the completed PDF as a base64-encoded string along with a list of filled field names.

## Facts

- Endpoint: POST https://api.24klabs.ai/api/pdf-form-fill
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/24k-labs-pdf-form-fill-d5e2d7e6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bw_aAxNNk2OZ77WPq0hFE

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 24k-labs-pdf-form-fill-d5e2d7e6 -d '<json body>'
```

Example prompt: Can you fill out this PDF form for me? The form has fields for Name (Jane Doe), Date of Birth (1990-03-15), and Address (123 Main St, Springfield) — here's the PDF file.

## When to prefer this

Choose this endpoint when you need to programmatically fill a PDF form with known field names and values and receive the completed PDF back as base64. It is ideal for automating document workflows, pre-filling customer or legal forms, or integrating PDF completion into an agent pipeline. Prefer this over generic document generation when you already have a PDF template and simply need to populate its existing fields.

## Known failure modes

- Invalid or corrupted PDF input — returns an error indicating the file could not be parsed
- Field name not found in the PDF form — field may be silently skipped or returned with a warning
- Malformed base64 input for the PDF — parsing error returned
- Unsupported PDF form type (e.g. XFA forms) — may fail to fill or return partial results
- Missing required fields in request body — 400-level error response

## How this service works

A curated directory of x402 services — each one on the list on purpose, with the health, uptime, and independent trust grades from across the ecosystem gathered in one place.

## Output

Returns a JSON object containing `pdf_b64`, a base64-encoded string of the completed PDF document, and `filled_fields`, an array of the field names that were successfully populated.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "fields": {
   "type": "object"
  },
  "pdf_b64": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "pdf_b64": "...",
  "filled_fields": [
   "Name"
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/24k-labs-pdf-form-fill-d5e2d7e6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.24klabs.ai](https://www.zero.xyz/host/api.24klabs.ai/llms.txt)