Any webhook → mailed letter

No native trigger for your tool? Any system that can fire a webhook can mail a letter: POST straight to paperplane’s open REST API from Webhooks by Zapier, Make’s HTTP module, or your own code — from $1.99, no API key.

All Webhook (generic) integration options · All integrations

Supported triggers and actions

Trigger	Action
Inbound webhook from any system	POST /v1/orders directly, fields mapped from the payload
Scheduled poll of a system with no webhook support	Same POST, run on a schedule against new/changed records

How to set it up

1Point the event — a form submission, a CRM update, an internal alert — at a webhook step: Webhooks by Zapier, Make’s HTTP module, n8n’s HTTP Request node, or a server-to-server call from your own code.
2Shape the payload into the order fields (mail_class, text or pdf_url, to, from, email) if the source data needs reshaping first.
3POST to paperplane’s POST /v1/orders endpoint with "sandbox": true while testing — free, instant, nothing mailed.
4Flip sandbox off to go live; pay from a prepaid credit balance, or handle the returned payment_url for a human to approve.

Direct POST from any webhook payload

{
  "mail_class": "first_class",
  "sandbox": true,
  "text": "Dear Ms. Alvarez, ...",
  "to":   { "name": "Maria Alvarez", "line1": "1 Main St",
            "city": "Richmond", "state": "VA", "zip": "23220" },
  "from": { "name": "Alex Rivera", "line1": "12 Grove Ave",
            "city": "Richmond", "state": "VA", "zip": "23221" },
  "email": "alex@example.com"
}

Same call as curl

curl -X POST https://sendpaperplane.com/v1/orders \
  -H 'Content-Type: application/json' \
  -d '{
    "mail_class": "first_class",
    "sandbox": true,
    "text": "Dear Ms. Alvarez, ...",
    "to":   { "name": "Maria Alvarez", "line1": "1 Main St",
              "city": "Richmond", "state": "VA", "zip": "23220" },
    "from": { "name": "Alex Rivera", "line1": "12 Grove Ave",
              "city": "Richmond", "state": "VA", "zip": "23221" },
    "email": "alex@example.com"
  }'

Under the hood

This is the same public REST API every native app and every other pairwise page on this directory calls underneath — there’s no separate "webhook mode," and no API key gate. If a system can fire an HTTP request with a JSON body, it has everything it needs to mail a letter.

Or skip the automation tool: ask Claude or ChatGPT

Every integration here sits on the same MCP endpoint agents use directly. Instead of wiring a trigger to an action, ask Claude or ChatGPT to draft and mail the letter. Same three tools (quote_letter, send_letter, get_letter_status), same price, same free sandbox.

Send mail from Claude Send mail from ChatGPT

Send your first letter from Webhook (generic).

Sandbox runs the whole pipeline for free and mails nothing. Live sends start at $1.99, one all-in price.

Send a letter

curl -X POST https://sendpaperplane.com/v1/orders \
  -H 'Content-Type: application/json' \
  -d '{
    "mail_class": "first_class",
    "sandbox": true,
    "text": "Dear Ms. Alvarez, ...",
    "to":   { "name": "Maria Alvarez", "line1": "1 Main St",
              "city": "Richmond", "state": "VA", "zip": "23220" },
    "from": { "name": "Alex Rivera", "line1": "12 Grove Ave",
              "city": "Richmond", "state": "VA", "zip": "23221" },
    "email": "alex@example.com"
  }'

Webhook (generic) integration options · All integrations

Common questions

What if my CRM or tool isn’t in Zapier/Make/n8n’s app list at all?

A raw webhook (from the tool itself, or a scheduled script polling its API) works exactly the same way — construct the JSON body and POST it. No app-specific integration is required on either side.

Is a direct API call less capable than a native app?

No — every native app and automation module on this directory is a thin wrapper over this same endpoint. A direct POST is the full capability, not a reduced one.

How do I avoid paying for a mapping mistake while I build this?

"sandbox": true runs the entire pipeline — screening, simulated fulfillment, a full response — for free and instantly, with nothing printed or mailed until you remove it.