# monero-lws ZeroMQ Usage
Monero-lws uses ZeroMQ-RPC to retrieve information from a Monero daemon,
ZeroMQ-SUB to get immediate notifications of blocks and transactions from a
Monero daemon, and ZeroMQ-PUB to notify external applications of payment_id
and new account (web)hooks.

## External "pub" socket
The bind location of the ZMQ-PUB socket is specified with the `--zmq-pub`
option. Users are still required to "subscribe" to topics:
  * `json-full-payment_hook`: A JSON object of a single webhook payment event
    that has recently triggered (identical output as webhook).
  * `msgpack-full-payment_hook`: A msgpack object of a webhook payment events
    that have recently triggered (identical output as webhook).
  * `json-full-new_account_hook`: A JSON object of a single new account
    creation that has recently triggered (identical output as webhook).
  * `msgpack-full-new_account_hook`: A msgpack object of a single new account
    creation that has recently triggered (identical output as webhook).


### `json-full-payment_hook`/`msgpack-full-payment_hook`
These topics receive PUB messages when a webhook ([`webhook_add`](administration.md)),
event is triggered for a payment (`tx-confirmation`). If the specified URL is
`zmq`, then notifications are only done over the ZMQ-PUB socket, otherwise the
notification is sent over ZMQ-PUB socket AND the specified URL. Invoking
`webhook_add` with a `payment_id` of zeroes (the field is optional in
`webhook_add`), will match on all transactions that lack a `payment_id`.

Example of the "raw" output from ZMQ-SUB side:

```json
json-full-payment_hook:{
  "index": 2,
  "event": {
    "event": "tx-confirmation",
    "payment_id": "4f695d197f2a3c54",
    "token": "single zmq wallet",
    "confirmations": 1,
    "event_id": "3894f98f5dd54af5857e4f8a961a4e57",
    "tx_info": {
      "id": {
        "high": 0,
        "low": 5666768
      },
      "block": 2265961,
      "index": 1,
      "amount": 3117324236131,
      "timestamp": 1687301600,
      "tx_hash": "ef3187775584351cc5109de124b877bcc530fb3fdbf77895329dd447902cc566",
      "tx_prefix_hash": "064884b8a8f903edcfebab830707ed44b633438b47c95a83320f4438b1b28626",
      "tx_public": "54dce1a6eebafa2fdedcea5e373ef9de1c3d2737ae9f809e80958d1ba4590d74",
      "rct_mask": "4cdc4c4e340aacb4741ba20f9b0b859242ecdad2fcc251f71d81123a47db3400",
      "payment_id": "4f695d197f2a3c54",
      "unlock_time": 0,
      "mixin_count": 15,
      "coinbase": false
    }
  }
}

```

Notice the `json-full-payment_hook:` prefix - this is required for the ZMQ PUB/SUB
subscription model. The subscriber requests data from a certain "topic" where
matching is done by string prefixes.

> `index` is a counter used to detect dropped messages.

> The `block` and `id` fields in the above example are NOT present when
`confirmations == 0`.

### `json-full-new_account_hook`/`msgpack-full-new_account_hook`
These topics receive PUB messages when a webhook ([`webhook_add`](administration.md)),
event is triggered for a new account (`new-account`). If the specified URL is
`zmq`, then notifications are only done over the ZMQ-PUB socket, otherwise the
notification is sent over ZMQ-PUB socket AND the specified URL. Invoking
`webhook_add` with a `payment_id` of zeroes (the field is optional in
`webhook_add`), will match on all transactions that lack a `payment_id`.

Example of the "raw" output from ZMQ-SUB side:

```json
json-full-new_account_hook:{
  "index": 2,
  "event": {
    "event": "new-account",
    "event_id": "c5a735e71b1e4f0a8bfaeff661d0b38a",
    "token": "",
    "address": "9zGwnfWRMTF9nFVW9DNKp46aJ43CRtQBWNFvPqFVSN3RUKHuc37u2RDi2GXGp1wRdSRo5juS828FqgyxkumDaE4s9qyyi9B"
  }
}
```

Notice the `json-full-new_account_hook:` prefix - this is required for the ZMQ
PUB/SUB subscription model. The subscriber requests data from a certain "topic"
where matching is done by string prefixes.

> `index` is a counter used to detect dropped messages.