Engine Health

Description

Returns the liveness status of the spot matching engine. Intended for load-balancer and dashboard probes; no authentication required.

HTTP Request

GET /spot/health (public — no auth required)

Weight

0 — public market-data endpoints have no per-IP weight limit today (MVP).

Response Example

200 OK

{
  "engine":      "running",
  "queue_depth": 0,
  "books_loaded": 1
}

Field	Values	Notes
engine	running / disabled	running — engine task is alive and accepting commands. disabled — server was started with SPOT_TRADING_ENABLED=false; no matching occurs.
queue_depth	integer	Current depth of the engine's mpsc command backlog. Healthy: 0 or single digits. Sustained high values indicate a load issue.
books_loaded	integer	Number of in-memory order books. MVP: 1 when engine=running, 0 when engine=disabled.

Error Responses

This endpoint always returns 200 OK. A disabled engine is reflected in the response body, not the HTTP status, so probes do not need to parse the body to detect basic reachability.

HTTP	error
500	(internal panic — rare)

Full list: Error Codes.

Code Examples

cURL

curl -s "https://api-sepolia.p99.world/api/v1/spot/health"

Python

import requests

BASE = "https://api-sepolia.p99.world/api/v1"

health = requests.get(f"{BASE}/spot/health").json()
print("engine:", health["engine"],
      "| queue_depth:", health["queue_depth"],
      "| books_loaded:", health["books_loaded"])

if health["engine"] != "running":
    print("WARNING: spot engine is not running")
elif health["queue_depth"] > 100:
    print("WARNING: engine queue_depth elevated:", health["queue_depth"])