# PDF Form Topology Analyzer

> PDF Form Topology Analyzer is a paid API for AI agents from x402.bakdupoffroad.com, paid per call via x402, $0.025/call, status down (last checked 2026-09-15).

Analyzes a base64-encoded PDF to extract form structure metadata including field counts, types, and AcroForm topology — without returning or retaining field content.

## Facts

- Endpoint: POST https://x402.bakdupoffroad.com/v1/document/form-topology
- Price: $0.025/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pdf-form-topology-analyzer-05cdad72
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_pwJ4rGhgDjhP4q0rHoSRQ

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 pdf-form-topology-analyzer-05cdad72 -d '<json body>'
```

Example prompt: Can you analyze the form structure of this PDF and tell me how many fields it has, what types they are, and whether it has any signature fields — here's the file as a base64 string: [base64data]

## When to prefer this

Choose this endpoint when you need a privacy-safe structural summary of a PDF form — field counts and types — without any risk of field value leakage. Ideal for preflight checks before automated form-filling pipelines, compliance audits requiring signature field detection, or document triage workflows that need to categorize PDFs by form complexity. Prefer this over full PDF parsers when you explicitly do NOT want field content returned or retained, and when per-call micropayment via x402/USDC on Base is acceptable.

## Known failure modes

- Invalid or malformed base64 input returns a parsing error
- PDF exceeds the service's advertised decoded-size limit, resulting in rejection
- Non-PDF file encoded as base64 may return an unsupported format error
- Payment failure or insufficient USDC balance returns HTTP 402
- PDF with no form fields returns topology with fieldCount of 0 and hasAcroForm false
- Network timeout on large PDF uploads

## How this service works

Private PDF preflight and authorized-video intelligence APIs paid per call with x402 USDC on Base.

## Output

Returns a JSON object containing: a job ID, form type (e.g. AcroForm), topology details (total field count, hasAcroForm flag, per-type field counts, widget page count, needsAppearances flag, signature field count), total page count, a SHA-256 hash of the source PDF, schema version, and economics metadata (net cost in micro-USD). Field names and values are deliberately omitted for privacy.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "pdfBase64": {
   "type": "string",
   "description": "A base64-encoded PDF, up to the service's advertised decoded-size limit. Customer text is never returned or retained.",
   "contentEncoding": "base64",
   "contentMediaType": "application/pdf"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "jobId": "00000000-0000-4000-8000-000000000000",
  "result": {
   "formType": "AcroForm",
   "topology": {
    "fieldCount": 12,
    "hasAcroForm": true,
    "fieldTypeCounts": {
     "text": 8,
     "button": 3,
     "signature": 1
    },
    "widgetPageCount": 2,
    "needsAppearances": false,
    "signatureFieldCount": 1
   },
   "pageCount": 2,
   "limitations": [
    "field names and values are deliberately omitted"
   ],
   "sourceSha256": "0000000000000000000000000000000000000000000000000000000000000000",
   "schemaVersion": "1"
  },
  "economics": {
   "netMicroUsd": 25000,
   "energyMicroUsd": 0,
   "revenueMicroUsd": 25000,
   "platformFeeMicroUsd": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pdf-form-topology-analyzer-05cdad72/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.bakdupoffroad.com](https://www.zero.xyz/host/x402.bakdupoffroad.com/llms.txt)