Transaction history — history

Subscribe to the history channel to follow an address's transaction activity. By default you receive confirmed history entries; add pending: true to receive the address's pending (mempool) transactions instead.

{ "action": "subscribe", "channel": "history", "address": "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4" }
{ "action": "subscribe", "channel": "history", "address": "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4", "pending": true }

history — confirmed

One event per new confirmed history entry. A single block may produce several for the same address.

{
  "type": "history",
  "data": {
    "address": "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
    "height": 840002,
    "block_n": 17,
    "txid": "4a5e1e...",
    "add": false,
    "amount": "20000",
    "addressBalance": "12395678"
  }
}

These are the same field names the REST address-history endpoint returns (height, txid, amount, addressBalance).

Field	Type	Description
type	string	Always "history".
data.address	string	The subscribed address.
data.height	integer	Block height where the change happened.
data.block_n	integer	Position of the transaction within the block.
data.txid	string	Transaction that caused the change.
data.add	boolean	true = received, false = spent.
data.amount	string	Amount changed, in the smallest unit (satoshis), as a string.
data.addressBalance	string	Balance right after this change, in the smallest unit (satoshis), as a string.

pending — pending (pending: true)

One event per pending (unconfirmed) transaction that touches the address. The data payload is the pending-transaction shape documented on the All pending transactions page, plus the matched address.

{
  "type": "pending",
  "address": "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
  "data": { "txid": "4a5e1e...", "seen_at": 1740391012, "vsize": 141, "fee": "1410", "feerate": 10.0, "vin": [], "vout": [] }
}

Field	Type	Description
type	string	Always "pending".
address	string	The subscribed address the transaction touched.
data	object	The pending-transaction payload — see All pending transactions.

Optional feature

Pending events are an optional feature and may not be available on every network. Subscribing where pending tracking is unavailable succeeds, but no pending events arrive.