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Documentation Index

Fetch the complete documentation index at: https://docs.thepostalcompany.com/llms.txt

Use this file to discover all available pages before exploring further.

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The Postal Company API

The Postal Company API lets you send physical letters anywhere in the world from your application. Write your letter content, provide a recipient address, and we handle printing, enveloping, and postal delivery.

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Quick start

1

Create an account

Sign up at thepostalcompany.com and log in to your dashboard.
2

Top up your balance

Go to the Balance page and purchase credits. Each letter costs €2.50.
3

Create an API key

Go to API Keys and create a new key. Copy it — it’s only shown once.
4

Send a letter

curl -X POST https://thepostalcompany.com/api/v1/letters \
  -H "Authorization: Bearer tpc_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "recipient": "Jane Doe",
    "address": {
      "street": "Keizersgracht",
      "number": "123",
      "postalcode": "1015 CJ",
      "city": "Amsterdam",
      "country": "NL"
    },
    "content": "Dear Jane,\n\nThis is a test letter sent via the API.\n\nBest regards"
  }'

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Key concepts

  • Credits — Pre-paid balance used to send letters. Each letter costs €2.50 via checkout or €2.25 via API.
  • API keys — Long-lived keys for authenticating API requests. You can create multiple keys and revoke them at any time.
  • Letters — Create letters as drafts to review them first, or send immediately. Once sent, letters are queued for printing and postal delivery.
  • Drafts — Letters created with send: false are saved as drafts. You can update them with PATCH and send them when ready with POST /api/v1/letters/:id/send.

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AI agent skill

If you’re using an AI coding agent (like Claude Code, Cursor, or Copilot), you can download our agent skill file to give your agent full knowledge of the API. Add it to your project or paste it into your agent’s context.