# Emboss — PDF Form-Filling and Fax Delivery API

> Emboss — PDF Form-Filling and Fax Delivery API is a paid API for AI agents from api.getemboss.ai, paid per call via x402, $0.03/call, status unknown (last checked 2026-10-17).

Fill a PDF form with AI-proposed answers sourced from supporting documents, then deliver the completed form by fax to a specified phone number.

## Facts

- Endpoint: POST https://api.getemboss.ai/pay/fax?utm_source=zero.xyz
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/emboss-pdf-form-filling-and-fax-delivery-api-db393567
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FHh-Q93pL6eVxfGnRMRhB

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 emboss-pdf-form-filling-and-fax-delivery-api-db393567 -d '<json body>'
```

Example prompt: Fill out this intake form at https://clinic.example.com/intake.pdf using my insurance card and ID documents I uploaded earlier, then fax the completed form to +12125550199.

## When to prefer this

Choose this endpoint when you need to both AI-fill a PDF form AND deliver it by fax in one workflow — particularly for healthcare, legal, or insurance use cases where fax is the required delivery channel. If you only need to fill a PDF without faxing it, use the sibling fill-only endpoint. Prefer this over manual faxing services when you also want AI-sourced field proposals with citations from supporting documents.

## Known failure modes

- Invalid or unreachable pdf_url returns an error before processing begins
- Fax number not in valid E.164 format causes request rejection
- More than one of pdf_url, pdf_base64, artifact_id, or sources provided simultaneously causes a validation error
- Referenced artifact_id not found or token mismatch returns unauthorized error
- PDF has no detectable form fields, resulting in an empty proposal
- Fax delivery failure to unreachable or invalid destination number
- Payment not completed via x402 results in 402 response before job is queued

## How this service works

Turn a blank PDF and your data into finished forms. Emboss proposes each answer with its source, fills and verifies the PDF, and returns a receipt.

## Output

Returns a JSON object containing a job_id, initial status ('ready'), a quote_id, a status_url for polling job progress, a proposal_id and proposal_url for reviewing AI-proposed answers with their sources, and a commit_token to authorize the final fill-and-send step.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "pattern": "^\\+[1-9][0-9]{6,14}$",
   "description": "Destination fax number in E.164 form."
  },
  "pdf_url": {
   "type": "string",
   "format": "uri",
   "description": "public https URL of the PDF form to process"
  },
  "sources": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "artifact_id"
    ],
    "properties": {
     "pages": {
      "type": "string",
      "description": "An optional page range, such as 1-3,7."
     },
     "artifact_id": {
      "type": "string",
      "description": "A prior artifact's id."
     },
     "artifact_token": {
      "type": "string",
      "description": "The bearer token for an anonymous artifact_id."
     }
    }
   },
   "maxItems": 20,
   "description": "A list of prior artifacts, faxed together as one packet, in place of pdf_url/pdf_base64/artifact_id -- exactly one of sources, pdf_url, pdf_base64, or artifact_id is required."
  },
  "pdf_base64": {
   "type": "string",
   "description": "the PDF form as base64 (alternative to pdf_url)",
   "contentEncoding": "base64"
  },
  "artifact_id": {
   "type": "string",
   "description": "The id of a previously registered artifact to fax, in place of pdf_url/pdf_base64 -- exactly one of pdf_url, pdf_base64, or artifact_id is required."
  },
  "artifact_token": {
   "type": "string",
   "description": "The bearer token for artifact_id, required whenever the artifact has no owner account (an anonymous caller's own prior result)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "job_id": "<uuid>",
  "status": "ready",
  "quote_id": "<uuid>",
  "status_url": "https://api.getemboss.ai/pay/jobs/<uuid>?token=<token>",
  "proposal_id": "<uuid>",
  "commit_token": "<token>",
  "proposal_url": "https://api.getemboss.ai/proposals/<uuid>?token=<token>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/emboss-pdf-form-filling-and-fax-delivery-api-db393567/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.getemboss.ai](https://www.zero.xyz/host/api.getemboss.ai/llms.txt)