3.2 KiB
Client
Clients establish a WebSocket connection to relays. Through this connection, clients communicate and subscribe to a range of Nostr events based on specified subscription filters. These filters define the Nostr events a client wishes to receive updates about.
::: info Clients do not need to sign up or create an account to use Nostr. Upon connecting to a relay, a client provides its subscription filters. The relay then streams events that match these filters to the client for the duration of the connection. :::
WebSocket events
Communication between clients and relays happen via WebSockets. The client will emit WebSocket events when the connection is opened, closed, when a message is received or when there's an error.
::: info
WebSocket events are not Nostr events. They are events emitted by the
WebSocket connection. The WebSocket :message
event, however, contains a Nostr event in its payload.
:::
connect
The :connect
event is fired when a connection with a WebSocket is opened. You must call Nostr::Client#connect
first.
client = Nostr::Client.new
relay = Nostr::Relay.new(url: 'wss://relay.damus.io', name: 'Damus')
client.on :connect do
# When this block executes, you're connected to the relay
end
# Connect to a relay asynchronously
client.connect(relay)
Once the connection is open, you can send events to the relay, manage subscriptions, etc.
::: tip
Define the connection event handler before calling
Nostr::Client#connect
. Otherwise,
you may miss the event.
:::
error
The :error
event is fired when a connection with a WebSocket has been closed because of an error.
client.on :error do |error_message|
puts error_message
end
# > Network error: wss://rsslay.fiatjaf.com: Unable to verify the
# server certificate for 'rsslay.fiatjaf.com'
message
The :message
event is fired when data is received through a WebSocket.
client.on :message do |message|
puts message
end
The message will be one of these 4 types, which must also be JSON arrays, according to the following patterns:
["EVENT", <subscription_id>, <event JSON>]
["OK", <event_id>, <true|false>, <message>]
["EOSE", <subscription_id>]
["NOTICE", <message>]
::: details Click me to see how a WebSocket message looks like
[
"EVENT",
"d34107357089bfc9882146d3bfab0386",
{
"content": "",
"created_at": 1676456512,
"id": "18f63550da74454c5df7caa2a349edc5b2a6175ea4c5367fa4b4212781e5b310",
"kind": 3,
"pubkey": "117a121fa41dc2caa0b3d6c5b9f42f90d114f1301d39f9ee96b646ebfee75e36",
"sig": "d171420bd62cf981e8f86f2dd8f8f86737ea2bbe2d98da88db092991d125535860d982139a3c4be39886188613a9912ef380be017686a0a8b74231dc6e0b03cb",
"tags":[
["p", "1cc821cc2d47191b15fcfc0f73afed39a86ac6fb34fbfa7993ee3e0f0186ef7c"]
]
}
]
:::
close
The :close
event is fired when a connection with a WebSocket is closed.
client.on :close do |code, reason|
puts "Error: #{code} - #{reason}"
end
::: tip This handler is useful to attempt to reconnect to the relay. :::