Error Codes

REST error shape

All REST errors return a JSON body with a single error field:

{
  "error": "human readable message"
}

REST status codes

Status	Example causes
`400 Bad Request`	Invalid market symbol, invalid price, tick-size violation, invalid quantity, invalid amend, missing username
`401 Unauthorized`	Missing `x-api-key`, invalid API key, missing `Authorization` header, invalid admin token
`403 Forbidden`	Order exists but belongs to a different trader
`404 Not Found`	Order not found, market not configured, target user not found
`409 Conflict`	Projected position limit breach, trading disabled, market disabled, market settled, username already exists
`429 Too Many Requests`	Per-user rate limit exceeded (100 ops/sec)
`500 Internal Server Error`	Numeric overflow or other internal failure

A 409 Conflict on order submission means your projected net position would exceed the +/-1000 limit for that market. Check your open orders and current position before resubmitting.

Example error response:

{
  "error": "projected net position for BTC-USD would be 1005; limit is +/-1000"
}

WebSocket `error` messages

error messages indicate protocol or transport-level problems. They are not tied to a specific trading operation.

Code	Meaning
`invalid_message`	The message could not be parsed or is missing required fields
`unsupported_channel`	Subscription requested for an unsupported channel
`invalid_api_key`	The API key provided during WebSocket authentication is invalid

Example:

{
  "type": "error",
  "code": "unsupported_channel",
  "message": "only the l3 channel is supported"
}

WebSocket `reject` messages

reject messages indicate a trading operation was refused. Each reject includes the original op, the request_id from your message, and a machine-readable code.

Code	Meaning
`unauthenticated`	Operation attempted before authenticating the WebSocket session
`trading_disabled`	Exchange-wide trading has been stopped by an admin
`invalid_market`	Market symbol format is invalid (must be `BASE-QUOTE`)
`market_not_configured`	No market definition exists for the requested symbol
`market_disabled`	Market exists but is currently disabled
`market_settled`	Market has been settled and no longer accepts orders
`invalid_price`	Price is zero or otherwise invalid
`tick_size_violation`	Price is not a multiple of the market’s tick size
`invalid_quantity`	Quantity is zero or otherwise invalid
`quantity_below_minimum`	Quantity is below the market’s minimum order quantity
`invalid_remaining`	Amend `remaining` is zero
`invalid_amend`	Amend would increase remaining quantity, which is not allowed
`order_not_found`	Order ID does not exist in the trader’s open orders
`order_not_owned`	Order exists but belongs to a different trader
`position_limit_exceeded`	Projected net position after the order would exceed +/-1000
`overflow`	Numeric overflow during position or PnL calculation

Example:

{
  "type": "reject",
  "op": "submit_order",
  "request_id": "req-1",
  "code": "position_limit_exceeded",
  "message": "projected net position for BTC-USD would be 1005; limit is +/-1000"
}

Health degradation

The GET /health endpoint reflects persistence state in the status field:

Persistence mode	`status` value
`disabled`	`ok`
`ok`	`ok`
`retrying`	`degraded`
`backpressured`	`degraded`
`stopped`	`degraded`

Example degraded response:

{
  "status": "degraded",
  "service": "exchange",
  "now": "2026-03-18T15:27:00.000000Z",
  "persistence": {
    "backend": "postgres",
    "mode": "retrying",
    "queue_depth": 412,
    "last_error": "connection refused"
  }
}

A degraded status means the persistence layer is not successfully writing. In-memory state is still live and the exchange continues to serve traffic, but data may not be durably stored.

Get Started

Authentication

REST API

WebSocket API

Operator Guide

Examples

REST error shape

REST status codes

WebSocket `error` messages

WebSocket `reject` messages

Health degradation

​REST error shape

​REST status codes

​WebSocket error messages

​WebSocket reject messages

​Health degradation

REST error shape

REST status codes

WebSocket `error` messages

WebSocket `reject` messages

Health degradation