The Blockbook Websocket interface allows clients to listen for events on the blockchain instead of polling for any changes which is a lot less efficient.

Authentication works the same as on HTTP routes. If you choose to give the API key as URL parameter then your URL will look like this: wss://api.chain49.com/{blockchain}/{api_key}/websocket


Many Websocket implementations do not support adding/changing the HTTP request headers and therefore require an alternative method for providing the API key.

Websocket communication format (based on JSON-RPC spec)

  "id": "49", 
  "method": "getInfo",  
  "params": "<same params as in the equivalent REST API calls>"

The following methods are available:

Info / UtilFiat Rates (from CoinGecko)TransactionsAccounts & Blocks

Examples for wscat:


wscat -c wss://api.chain49.com/ethereum/$C49_API_KEY/websocket

# wait for connect, then paste example request objects into wscat prompt

# example request "getInfo"
{ "id": "49", "method": "getInfo", "params": "" }

# example req with params "getAccountInfo"
{ "id": "49", "method": "getAccountInfo", "params": { "descriptor": "0xba98d6a5ac827632e3457de7512d211e4ff7e8bd", "details": "txids" } }

# example subscription
{ "id": "49", "method": "subscribeNewTransaction", "params": "" }


In addition to requesting info with the methods described above, the client can subscribe to the following events:

subscribeNewBlock - new block added to blockchain
subscribeNewTransaction - new transaction added to blockchain (all addresses)
subscribeAddresses - new transaction for a given address (list of addresses) added to mempool
subscribeFiatRates - new currency rate ticker

Example for subscribing to an address (or multiple addresses):

    "addresses":["mnYYiDCb2JZXnqEeXta1nkt5oCVe2RVhJj", "tb1qp0we5epypgj4acd2c4au58045ruud2pd6heuee"]  

There can be always only one subscription of given event per connection, i.e. new list of addresses replaces previous list of addresses.


If there is reorg on the backend (blockchain), you will get a new block hash with the same or even smaller height if the reorg is deeper

Websocket Playground

A great way to explore the Websocket API is with our Websocket playground where you can try out every method and subscription that is possible.

You can find the playground here: https://api.chain49.com/websocket-playground