generated: '2026-07-21'
method: searched
source: https://developer.webull.com/apis/docs
docs: https://developer.webull.com/apis/docs/webull-open-api-reference
authentication:
  style: app-key + HMAC-SHA1 request signing (per-request x-signature); OAuth 2.0 for Connect API
  ref: authentication/webull-authentication.yml
transport:
  https_required: true
  interface_version_header: x-version   # accepts v2
idempotency:
  supported: true
  mechanism: client-order-id
  description: >-
    Order-placing operations accept a caller-supplied client_order_id (client-order-id).
    Reusing the same client_order_id prevents duplicate order submission, giving
    at-most-once semantics on the mutation endpoints (place / batch-place / option-place /
    futures-place / crypto-place / event-place). Preview endpoints
    (preview_stock_order / preview_option_order) let a caller validate before committing.
pagination:
  style: cursor/page-size
  params: [page_size, series_symbol, last_client_order_id]
  notes: >-
    List endpoints (order history, event series/instruments) page via page_size and
    a continuation key; order history is windowed by date range.
request_tracing:
  nonce_header: x-signature-nonce
  timestamp_header: x-timestamp
versioning:
  scheme: interface-version-header (x-version=v2) + date-based changelog
  ref: lifecycle/webull-lifecycle.yml
rate_limiting:
  ref: rate-limits (see lifecycle + llms)
  us:
    market_data: 600 req/min
    order_place_replace_cancel: 600 req/min
    order_query: 2 req/2s
    auth_create_check: 10 req/30s
  hk:
    market_data: 60 req/60s
    order_place: 15 req/s (US) / 1 req/s (HK, A-share)
    order_preview: 40 req/10s
    order_query: 40 req/2s
error_envelope:
  ref: errors/webull-problem-types.yml
  notes: HTTP status + JSON body with code/message; SDKs raise typed errors.
streaming:
  trading_events: gRPC (events-api.webull.com) — see grpc/webull-events.proto
  market_data: MQTT / S2S streaming (data-api.webull.com) — see grpc/webull-quote.proto