Introduction

WebSocket connection setup, limits, and error handling.

Endpoints

Environment	URL
Mainnet	wss://api.hotstuff.trade/ws
Testnet	wss://testnet-api.hotstuff.trade/ws

Limits

Limit	Value
Connections per IP	100
Subscriptions per IP	1,000
Inbound messages per minute	2,000
Max message size	512 bytes

Message Buffering

Each client has a 256-message outbound buffer. When the buffer fills (slow consumer), new messages are dropped silently—the connection remains open with no error sent.

Slow clients will miss data without warning. Process messages promptly to avoid gaps.

Rate Limiting

Exceeding 2,000 inbound messages/min triggers a JSON-RPC error. The connection stays open:

{
  "jsonrpc": "2.0",
  "id": "1",
  "error": {
    "code": -32001,
    "message": "Message rate limit exceeded",
    "data": {
      "retry_after": 12
    }
  }
}

The retry_after field indicates seconds to wait before sending more messages.

JSON-RPC post Methods (Info + Exchange)

In addition to subscriptions, WebSocket supports request-response calls through:

• method: "post"
• params.type: "info" for all Info REST endpoints
• params.type: "action" for all Exchange REST endpoints

The payload format mirrors the REST API reference methods and params. See the WSS section Info + Exchnage Requests for separate interactive pages:

• Info Requests
• Action Requests

Error Codes

Code	Name	Description
-32700	Parse Error	Invalid JSON
-32600	Invalid Request	Malformed JSON-RPC 2.0
-32601	Method Not Found	Unknown method
-32602	Invalid Params	Bad method parameters
-32603	Internal Error	Server-side failure
-32000	Server Error	Generic server error
-32001	Too Many Requests	Rate limit exceeded