> Complete API reference for the Cost+ Payment API The Cost+ Payment API lets you create and manage orders, process payments, handle refunds, and manage payment links. ## Base URL | | URL | |---|---| | **API** | `https://api.costplus.online/v1` | > [!NOTE] > There is no separate sandbox URL. Sandbox vs production mode is determined by the API key — use a key from a sandbox website in the [Merchant Portal](https://dashboard.costplus.io/) for testing, or a production website for live transactions. ## Authentication All API requests use **HTTP Basic Auth**. Use your API key as the username with an empty password: ```bash curl -u {api_key}: https://api.costplus.online/v1/orders/ ``` See the [Authentication guide](/docs/getting-started/authentication) for detailed setup instructions. ## API Sections ### Orders API Create, retrieve, update, and cancel payment orders. Includes refund, capture, and void operations. ### Payment Links API Create and manage reusable payment links that support multiple payment attempts. ### Search API Search across your orders using flexible criteria. ### Self Service API Manage your project settings and retrieve supported currencies. ### Webhooks Receive real-time notifications when order or transaction statuses change. See the [Webhook Event Schemas](/api-reference/webhooks) page for payload details. ## Usage Guides For step-by-step walkthroughs of common integration patterns, see the [Guides](/docs/guides) section: - [Hosted Payment Page](/docs/guides/hosted-payment-page) — accept payments via redirect - [Recurring Payments](/docs/guides/recurring-payments) — set up subscriptions and scheduled billing - [One-Click Payments](/docs/guides/one-click-payments) — fast checkout for returning customers - [Auth / Capture / Void](/docs/guides/auth-capture-void) — two-step payment flows - [Refunds](/docs/guides/refunds) — process full and partial refunds - [Webhooks](/docs/guides/webhooks) — receive real-time status notifications - [Payment Links](/docs/guides/payment-links) — create reusable payment links