> For the complete documentation index, see [llms.txt](https://support.swisspay.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.swisspay.ai/readme.md).

# SwissPay developer docs

Welcome. This is the reference for the **SwissPay API** — the public endpoints you can call today to create payments and manage customers.

{% hint style="info" %}
The SwissPay API is **live** at `https://app.swisspay.ai`. Use a **test key** (`sk_test_…`) for development and a **live key** (`sk_live_…`) to move real money — the same base URL serves both, and the key you send decides the mode. See [Authentication](/api-reference/authentication.md). Questions? Write to <support@swisspay.ai>.
{% endhint %}

## I want to…

* **Make my first API call** → [Quickstart](/api-reference/quickstart.md)
* **Get an API key** → [Authentication](/api-reference/authentication.md)
* **Understand idempotent retries** → [Idempotency](/api-reference/idempotency.md)
* **Handle declines and errors correctly** → [Errors](/api-reference/errors.md)
* **Use test cards in test mode** → [Test cards](/api-reference/test-cards.md)
* **Create a payment** → [Payments](/api-reference/payments.md)
* **Create a customer** → [Customers](/api-reference/customers.md)
* **Let an AI agent call the API** → [Using the API with AI agents (MCP)](/api-reference/using-with-ai-agents.md)
* **Get the OpenAPI spec** → [OpenAPI specification](/api-reference/openapi.md)

## Need help?

* Look something up in the [glossary](/reference/glossary.md).
* Email <support@swisspay.ai> — we usually respond within one business day.
* Report a security issue: see [Responsible disclosure](/security/responsible-disclosure.md).