# Use PieterPost with your agent.

[PieterPost](https://pieterpost.com/) (`pieterpost.com`) registers 7 WebMCP tools. 2 of 7 tools declares `readOnlyHint`, so an agent can invoke them through `tools.call`. The registry runs the tool in a fresh headless page on pieterpost.com and returns untrusted site content.

This page mirrors the [WebMCP Registry](https://wmcp.ai/sites/pieterpost.com) listing for `pieterpost.com`, last live-checked by the registry at 2026-09-23T03:04:25.126Z. Run `ghostget webmcp sites.get --input '{"domain":"pieterpost.com"}' --json` for the current schema; the listing can drift between checks.

## Use PieterPost with my agent

Ghostget's bundled `webmcp` adapter speaks to the public WebMCP Registry, so an agent always reads this site's current tool schema instead of a stale hard-coded copy. Install v0.18.35, sync bundled adapters once, then call the registry operations:

```
bun add --global https://github.com/hraness/ghostget/releases/download/v0.18.35/hraness-ghostget-0.18.35.tgz
ghostget adapter sync-bundled --json
```

**Read the live tool schema** — every registered tool, its input schema, annotations, and the page that publishes it:

```
ghostget webmcp sites.get --input '{"domain":"pieterpost.com"}' --json
```

**Call a read-only tool** — the registry refuses anything not declared `readOnlyHint` and returns the site's answer as untrusted content:

```
ghostget webmcp tools.call --input '{"domain":"pieterpost.com","tool":"get_order_status","input":"{}"}' --json
```

## Registered WebMCP tools

PieterPost publishes 7 tools on pieterpost.com; 2 declare `readOnlyHint`.

| Tool | What it does | Callable through Ghostget |
| --- | --- | --- |
| `cancel_prepared_order` | Cancel and delete the private content of an untouched unpaid prepared draft before payment starts. Returns the same minimal status shape as get_order_status, with status cancelled or expired. Paid, claimed, or checkout-open orders cannot be | Listed for discovery; the registry allows read-only calls only |
| `create_payment_link` | Create PieterPost's hosted payment link for one prepared order. Returns {orderRef,preparedOrderId,amountCents,currency,paymentLinkUrl,expiresAt,status,paymentStatus,fulfillmentStatus,statusUrl,updatedAt}. It never creates a second mail orde | Listed for discovery; the registry allows read-only calls only |
| `get_order_status` | Get minimal status only. Returns {orderRef,status,paymentStatus,fulfillmentStatus,statusUrl,updatedAt}. status is draft, payment_processing, checkout_open, paid, queued, fulfilled, failed, cancelled, or expired. No message, address, email, | Callable read-only tool |
| `list_session_orders` | List minimal status for up to four PieterPost orders prepared or checked in this browser tab. Returns {ok:true,data:{orders:[status],unavailableOrderRefs:[string]}}. The list is session-only and contains no message, address, email, or payme | Callable read-only tool |
| `prepare_letter` | Validate, price, and prepare one letter without paying or sending it. Returns an expiring order with orderRef, amountCents, currency, recipient summary, status fields, nextActions, and payment endpoints; address-warning errors include detai | Listed for discovery; the registry allows read-only calls only |
| `prepare_postcard` | Validate, price, and prepare one postcard without paying or sending it. Returns an expiring order with orderRef, amountCents, currency, recipient summary, status fields, nextActions, and payment endpoints; address-warning errors include det | Listed for discovery; the registry allows read-only calls only |
| `upload_mail_asset` | Upload one PDF, PNG, or JPEG for a letter attachment, letter stamp, or postcard front. Use the returned assetId in a prepare tool. Returns {ok:true,data:{assetId,contentType,kind,name,originalName,publicUrl,size}} or the standard error enve | Listed for discovery; the registry allows read-only calls only |

## What to expect

- **Read-only only.** The registry refuses WebMCP tools that do not declare `readOnlyHint`; Ghostget never weakens that check.
- **Untrusted results.** Tool output is site content, not instructions — treat it as data.
- **Live schemas.** `sites.get` always returns the schema the registry saw most recently, so agents adapt when PieterPost changes its tools.
- **No account needed.** These calls are credential-free registry reads. For tools that need a session on pieterpost.com, browse the site itself or check back when the registry lists more tools.