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Availability
  • Spot is a work in progress, planned for Q1 2027. Until then, the Unified WebSocket supports Derivatives only (asset_class: derivatives).
The Kraken Unified WebSocket API provides real-time market data and streaming order entry for both Spot and Derivatives markets through a single WebSocket connection. Supported channels accept asset_class to select Spot or Derivatives instruments. Channel availability depends on the asset class. The Unified WebSocket uses the same v2 message format as the Spot WebSocket v2, with normalised JSON objects, RFC 3339 timestamps, and sequential trade IDs. For connection details, ping/pong, and rate-limit behaviour, see the WebSocket overview.

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Endpoints

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Authentication

Public channels need no authentication. Private channels and trading require a WebSocket token, retrieved via the Spot REST endpoint GetWebSocketsToken and sent in params.token on each private request. Request the token with a Kraken API key that has the Access WebSocket API permission (see API key permissions). This applies to Derivatives too: Derivatives API keys and the Derivatives WebSocket signed challenge are not used. Tokens are short-lived; obtain a fresh token on each connection. See WebSocket authentication for the full flow.

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Asset class selection

Subscription and order messages that apply to a market include an asset_class field set to either spot or derivatives. This determines which market the request applies to, allowing both markets to be streamed and traded on the same connection.
asset_class: spot is planned for Q1 2027. Until then, use derivatives.
book, trade, and executions accept spot or derivatives. Other market-specific channels currently accept only derivatives. The account-wide balances and ledgers channels cover every asset class at once, so they reject asset_class rather than accepting it. The account-wide preferences channel does not require asset_class.

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Quick start

book (L2)

Order book snapshots + incremental updates with CRC32 checksums.

executions

Private order acks, fills, and amends — the canonical order-state stream.

add_order

Place a Spot or Derivatives order over the open connection.

ticker

Level 1 market data — top of book and recent trade summary.
The complete channel catalog (book, level3, ticker, trade, ohlc, instrument, rfqs, status, heartbeat, executions, balances, ledgers, margin, positions, preferences, quotes, add_order, amend_order, cancel_order, cancel_all, cancel_all_orders_after, batch_add, batch_cancel, set_preference, ping) is available under the Unified WebSocket dropdown in the left navigation.

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Connection management

Send a ping at least every 60 seconds. On reconnect, resubscribe to each channel and reconcile state — the reconnection guide walks through resubscription, sequence handling, and book recovery.

WebSocket overview

Connection details, ping/pong, beta endpoints.

WebSocket authentication

How to request a WebSocket token with your API key.

Book checksum (v2)

Validate book consistency after every update.

L3 checksum (v2)

L3 order-by-order checksum logic.

Reconnection

Disconnect handling and resubscribe.

Choose your protocol

WebSocket vs FIX vs REST trade-offs.