DOCS

Limits & errors

What counts against you, what doesn't, and how errors are shaped.

Streaming limits

Messages are unlimited on all paid plans — there are no per-tick fees or overage charges.
Connections: up to 5 concurrent WebSocket connections per key. Need more? Ask us.
Symbols: subscribe to as many symbols as you like on a single connection.

REST rate limits

REST is intended for snapshots and backfill, so it's rate-limited per key:

Endpoint	Limit
`/quote`, `/symbols`, `/options`	60 requests / minute
`/ticks` (backfill)	20 requests / minute

Every response includes X-RateLimit-Remaining and X-RateLimit-Reset headers. Exceeding a limit returns 429 — back off and retry after the reset.

Error shape

All errors share the same JSON envelope with a stable code:

{
  "error": {
    "code": "plan_required",
    "message": "Options data requires the Pro plan.",
    "status": 403
  }
}

Status codes

Status	Code	Meaning
`400`	`bad_request`	Malformed parameters (e.g. bad date range).
`401`	`unauthorized`	Missing or invalid API key.
`402`	`no_subscription`	No active subscription for live data.
`403`	`plan_required`	Your plan doesn't include this feed/symbol.
`404`	`unknown_symbol`	Symbol not found — see symbols.
`429`	`rate_limited`	Too many REST requests — back off.
`5xx`	`internal`	Our fault. Retry with backoff; we're paged.

tip

The SDKs raise typed exceptions/errors carrying the code, so you can branch on it without parsing strings.