Access & limits
Free, authless access — and the rules that come with it.
Free & authless
No API key, no sign-up. Please stay under ~60 requests/minute per IP.
Best-effort, no SLA
Data is derived from NASDAQ's public trade-halt feed and provided as-is — not a system of record, and not for automated trading decisions. Always confirm a stock's status with your broker or the exchange feed.
Caching
Responses are CDN-cached for a few seconds, so polling faster yields no fresher data. Use the ETag for conditional requests and read meta.data_age_ms / meta.stale.
CORS
The API does not send CORS headers, so call it from your backend rather than directly from a browser page.
Versioning
Within v1, changes are additive only (new fields, appended enum values) — ignore unknown fields. Breaking changes ship as a new version path.