> For the complete documentation index, see [llms.txt](https://k4k3ru.gitbook.io/k4k3ru-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://k4k3ru.gitbook.io/k4k3ru-docs/api.md).

# API

K4K3RU provides JSON-RPC request-response operations and secure WebSocket connections through a single public API endpoint.

## Endpoints

| Interface           | Endpoint                  |
| ------------------- | ------------------------- |
| JSON-RPC            | `https://api.k4k3ru.com/` |
| WebSocket           | `wss://api.k4k3ru.com/`   |
| MCP Streamable HTTP | `https://mcp.k4k3ru.com/` |

Use HTTPS for JSON-RPC requests and WSS for real-time subscriptions. Unencrypted HTTP and WebSocket connections are not public API interfaces.

MCP-compatible clients can use the separate authenticated MCP endpoint. See [MCP](/k4k3ru-docs/mcp.md) for connection and tool details.

See [JSON-RPC Format](/k4k3ru-docs/api/json-rpc.md) for the common request and response envelopes.

See [API Request Authentication](/k4k3ru-docs/api/authentication.md) to sign requests for protected methods.

## API Domains

The API reference is organized by capability domain:

### CRM

Create and manage accounts, credentials, authentication, and related account capabilities.

See [CRM API](/k4k3ru-docs/api/crm.md).

### Payment

Create and manage payments and related payment workflows.

See [Payment API](/k4k3ru-docs/api/payment.md).

### Market Hub

Access normalized financial market data and real-time subscriptions.

See [Market Hub API](/k4k3ru-docs/api/market-hub.md).


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