# PostAgent Print & Mail

> PostAgent Print & Mail is a paid API for AI agents from api.postagent.sh, paid per call via x402, $1.24/call, status unknown (last checked 2026-10-12).

Prints and mails a physical US letter or postcard via USPS, paid in USDC using the x402 payment protocol

## Facts

- Endpoint: POST https://api.postagent.sh/v1/print?utm_source=zero.xyz
- Price: $1.24/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 1
- Tags: x402
- Canonical page: https://www.zero.xyz/c/postagent-print-mail-9eab8b4e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RO2lIMiJqU2_VzS7uCRUh

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 postagent-print-mail-9eab8b4e -d '<json body>'
```

Example prompt: Send this HTML invoice as a physical USPS letter to Jane Smith at 123 Main St, Austin TX 78701 — I already have a quote locked in, so go ahead and pay and mail it, and notify me at https://myapp.com/webhooks/mail when it's done.

## When to prefer this

Use this endpoint when you need to physically mail a document to a US address via USPS, especially when paying programmatically in USDC. Prefer this over email or digital delivery when legal proof of delivery (certified/registered mail) is required, when the recipient has no digital access, or when a physical postcard or letter is the required medium. It fits well into agentic workflows that handle invoicing, legal notices, government correspondence, or marketing mail entirely in code.

## Known failure modes

- Invalid or expired quote ID — must re-run POST /v1/quotes to get a fresh locked price
- Payment failure — USDC payment via x402 not completed or insufficient funds
- Invalid recipient address — address failed USPS verification (use POST /v1/verify first)
- Unsupported document format — file type not in PDF/HTML/Markdown/DOCX/image set
- Document ID not found — must upload via POST /v1/documents before calling /v1/print
- Webhook URL unreachable — optional webhookUrl returns non-2xx during registration

## How this service works

Print and mail physical US letters (PDF, HTML, Markdown, DOCX, or image) and postcards via USPS, paid in USDC — with certified/registered proof options and standalone address verification at POST /v1/verify. Integration flow: POST /v1/documents to upload, POST /v1/quotes to lock a fixed USDC price for a recipient, then pay the returned per-quote x402 URL to create and mail the piece. Price is fixed per quote.

## Output

Returns a job confirmation indicating the letter or postcard has been created and queued for USPS mailing, along with a job ID and status. If a webhookUrl was provided, the endpoint will POST job status updates (e.g. printed, mailed, delivered) to that URL as the piece moves through the mail system.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "webhookUrl": {
       "type": "string",
       "description": "Optional HTTPS URL that receives job status webhooks after the letter is created."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/postagent-print-mail-9eab8b4e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.postagent.sh](https://www.zero.xyz/host/api.postagent.sh/llms.txt)