---
title: "Start building"
description: "A clear path from your first request to a verified payment."
---

# Start building

A clear path from your first request to a verified payment.

## Your first integration

<!-- steps -->

1. Open the [merchant dashboard](https://app.coinssend.com/) and find your Merchant ID and API key in merchant settings.
2. Keep your API key on your server. Follow the [authentication guide](/payments/guides/authentication/) and validate request signing against the [signature test vectors](/signature-test-vectors.json).
3. Create an invoice from your backend using the [invoice guide](/payments/guides/invoices/). Persist its identifier and send the customer to the returned payment URL.
4. Configure and verify [webhooks](/payments/guides/webhooks/). Confirm payment from verified events and persisted status; a browser redirect alone is not proof of payment.
5. Handle duplicate notifications and [ambiguous request outcomes](/payments/guides/rate-limits/). Check the current API contract before retrying a write.

## Explore the live coin catalog

This public read-only request lets you inspect the current catalog before making signed requests.

```bash
curl 'https://api.coinssend.com/v1/coins-and-fee' \
  --header 'Accept: application/json'
```

[Continue with the full quickstart](/payments/quickstart/)

## Build with your agent

Connect your coding assistant to the docs or start with a task prompt.

[Agent setup and prompts](/agents/)

The interface and introductory guides are available in six languages. Detailed API guides currently use the English reference.