Merge pull request 'Add support for Lightning Zaps' (#190) from feature/170-nostr_zaps into master

Reviewed-on: #190

.env.test

@@ -18,6 +18,9 @@ LNDHUB_API_URL='http://localhost:3026'
 LNDHUB_PUBLIC_URL='https://lndhub.kosmos.org'
 LNDHUB_PUBLIC_KEY='024cd3be18617f39cf645851e3ba63f51fc13f0bb09e3bb25e6fd4de556486d946'
 
+NOSTR_PRIVATE_KEY='7c3ef7e448505f0615137af38569d01807d3b05b5005d5ecf8aaafcd40323cea'
+NOSTR_PUBLIC_KEY='bdd76ce2934b2f591f9fad2ebe9da18f20d2921de527494ba00eeaa0a0efadcf'
+
 RS_STORAGE_URL='https://storage.kosmos.org'
 RS_REDIS_URL='redis://localhost:6379/1'
 

app/controllers/lnurlpay_controller.rb

@@ -1,13 +1,15 @@
 class LnurlpayController < ApplicationController
   before_action :check_service_available
   before_action :find_user
+  before_action :set_cors_access_control_headers, only: [:invoice]
 
   MIN_SATS = 10
   MAX_SATS = 1_000_000
   MAX_COMMENT_CHARS = 100
 
+  # GET /.well-known/lnurlp/:username
   def index
-    render json: {
+    res = {
       status: "OK",
       callback: "https://#{Setting.accounts_domain}/lnurlpay/#{@user.cn}/invoice",
       tag: "payRequest",
@@ -16,8 +18,16 @@ class LnurlpayController < ApplicationController
       metadata: metadata(@user.address),
       commentAllowed: MAX_COMMENT_CHARS
     }
+
+    if Setting.nostr_enabled?
+      res[:allowsNostr] = true
+      res[:nostrPubkey] = Setting.nostr_public_key
+    end
+
+    render json: res
   end
 
+  # GET /.well-known/keysend/:username
   def keysend
     http_status :not_found and return unless Setting.lndhub_keysend_enabled?
 
@@ -32,8 +42,9 @@ class LnurlpayController < ApplicationController
     }
   end
 
+  # GET /lnurlpay/:username/invoice
   def invoice
-    amount = params[:amount].to_i / 1000 # msats
+    amount = params[:amount].to_i / 1000 # msats to sats
     comment = params[:comment] || ""
     address = @user.address
 
@@ -42,53 +53,109 @@ class LnurlpayController < ApplicationController
       return
     end
 
-    if !valid_comment?(comment)
+    if params[:nostr].present? && Setting.nostr_enabled?
-      render json: { status: "ERROR", reason: "Comment too long" }
+      handle_zap_request amount, params[:nostr], params[:lnurl]
-      return
+    else
+      handle_pay_request address, amount, comment
+    end
+  end
+
+  private
+
+    def set_cors_access_control_headers
+      headers['Access-Control-Allow-Origin'] = "*"
+      headers['Access-Control-Allow-Headers'] = "*"
+      headers['Access-Control-Allow-Methods'] = "GET"
     end
 
-    memo = "To #{address}"
+    def check_service_available
-    memo = "#{memo}: \"#{comment}\"" if comment.present?
+      http_status :not_found unless Setting.lndhub_enabled?
+    end
 
-    payment_request = @user.ln_create_invoice({
+    def find_user
-      amount: amount, # we create invoices in sats
+      @user = User.where(cn: params[:username], ou: Setting.primary_domain).first
-      memo: memo,
+      http_status :not_found if @user.nil?
-      description_hash: Digest::SHA2.hexdigest(metadata(address)),
+    end
-    })
 
-    render json: {
+    def metadata(address)
-      status: "OK",
+      "[[\"text/identifier\",\"#{address}\"],[\"text/plain\",\"Sats for #{address}\"]]"
-      successAction: {
+    end
-        tag: "message",
-        message: "Sats received. Thank you!"
-      },
-      routes: [],
-      pr: payment_request
-    }
-  end
 
-  private
+    def valid_amount?(amount_in_sats)
+      amount_in_sats <= MAX_SATS && amount_in_sats >= MIN_SATS
+    end
 
-  def find_user
+    def valid_comment?(comment)
-    @user = User.where(cn: params[:username], ou: Setting.primary_domain).first
+      comment.length <= MAX_COMMENT_CHARS
-    http_status :not_found if @user.nil?
+    end
-  end
 
-  def metadata(address)
+    def handle_pay_request(address, amount, comment)
-    "[[\"text/identifier\", \"#{address}\"], [\"text/plain\", \"Send sats, receive thanks.\"]]"
+      if !valid_comment?(comment)
-  end
+        render json: { status: "ERROR", reason: "Comment too long" }
+        return
+      end
 
-  def valid_amount?(amount_in_sats)
+      desc = "To #{address}"
-    amount_in_sats <= MAX_SATS && amount_in_sats >= MIN_SATS
+      desc = "#{desc}: \"#{comment}\"" if comment.present?
-  end
 
-  def valid_comment?(comment)
+      invoice = LndhubManager::CreateUserInvoice.call(
-    comment.length <= MAX_COMMENT_CHARS
+        user: @user, payload: {
-  end
+          amount: amount, # sats
+          description: desc,
+          description_hash: Digest::SHA256.hexdigest(metadata(address)),
+        }
+      )
 
-  private
+      render json: {
+        status: "OK",
+        successAction: {
+          tag: "message",
+          message: "Sats received. Thank you!"
+        },
+        routes: [],
+        pr: invoice["payment_request"]
+      }
+    end
 
-  def check_service_available
+    def nostr_event_from_payload(nostr_param)
-    http_status :not_found unless Setting.lndhub_enabled?
+      event_obj = JSON.parse(nostr_param).transform_keys(&:to_sym)
-  end
+      Nostr::Event.new(**event_obj)
+    rescue => e
+      return nil
+    end
+
+    def valid_zap_request?(amount, event, lnurl)
+      NostrManager::VerifyZapRequest.call(
+        amount: amount, event: event, lnurl: lnurl
+      )
+    end
+
+    def handle_zap_request(amount, nostr_param, lnurl_param)
+      event = nostr_event_from_payload(nostr_param)
+
+      unless event.present? && valid_zap_request?(amount*1000, event, lnurl_param)
+        render json: { status: "ERROR", reason: "Invalid zap request" }
+        return
+      end
+
+      # TODO might want to use the existing invoice and zap record if there are
+      # multiple calls with the same zap request
+
+      desc = "Zap for #{@user.address}"
+      desc = "#{desc}: \"#{event.content}\"" if event.content.present?
+
+      invoice = LndhubManager::CreateUserInvoice.call(
+        user: @user, payload: {
+          amount: amount, # sats
+          description: desc,
+          description_hash: Digest::SHA256.hexdigest(event.to_json),
+        }
+      )
+
+      @user.zaps.create! request: event,
+                         payment_request: invoice["payment_request"],
+                         amount: amount
+
+      render json: { status: "OK", pr: invoice["payment_request"] }
+    end
 end

app/controllers/webhooks_controller.rb

@@ -2,45 +2,66 @@ class WebhooksController < ApplicationController
   skip_forgery_protection
 
   before_action :authorize_request
+  before_action :process_payload
 
   def lndhub
-    begin
+    @user = User.find_by!(ln_account: @payload[:user_login])
-      payload = JSON.parse(request.body.read, symbolize_names: true)
+
-      head :no_content and return unless payload[:type] == "incoming"
+    if zap = @user.zaps.find_by(payment_request: @payload[:payment_request])
-    rescue
+      zap_receipt = NostrManager::CreateZapReceipt.call(
-      head :unprocessable_entity and return
+        zap: zap,
+        paid_at: Time.parse(@payload[:settled_at]).to_i,
+        preimage: @payload[:preimage]
+      )
+      zap.update! receipt: zap_receipt.to_h
+      NostrManager::PublishZapReceipt.call(zap: zap)
     end
 
-    user = User.find_by!(ln_account: payload[:user_login])
+    send_notifications
-    notify = user.preferences[:lightning_notify_sats_received]
-    case notify
-    when "xmpp"
-      notify_xmpp(user.address, payload[:amount], payload[:memo])
-    when "email"
-      NotificationMailer.with(user: user, amount_sats: payload[:amount])
-                        .lightning_sats_received.deliver_later
-    end
 
     head :ok
   end
 
   private
 
-  # TODO refactor into mailer-like generic class/service
-  def notify_xmpp(address, amt_sats, memo)
-    payload = {
-      type: "normal",
-      from: Setting.xmpp_notifications_from_address,
-      to: address,
-      subject: "Sats received!",
-      body: "#{helpers.number_with_delimiter amt_sats} sats received in your Lightning wallet:\n> #{memo}"
-    }
-    XmppSendMessageJob.perform_later(payload)
-  end
-
   def authorize_request
     if !ENV['WEBHOOKS_ALLOWED_IPS'].split(',').include?(request.remote_ip)
       head :forbidden and return
     end
   end
+
+  def process_payload
+    @payload = JSON.parse(request.body.read, symbolize_names: true)
+    unless @payload[:type] == "incoming" &&
+           @payload[:state] == "settled"
+      head :no_content and return
+    end
+  rescue
+    head :unprocessable_entity and return
+  end
+
+  def send_notifications
+    case @user.preferences[:lightning_notify_sats_received]
+    when "xmpp"
+      notify_xmpp
+    when "email"
+      notify_email
+    end
+  end
+
+  # TODO refactor into mailer-like generic class/service
+  def notify_xmpp
+    XmppSendMessageJob.perform_later({
+      type: "normal",
+      from: Setting.xmpp_notifications_from_address,
+      to: @user.address,
+      subject: "Sats received!",
+      body: "#{helpers.number_with_delimiter @payload[:amount]} sats received in your Lightning wallet:\n> #{@payload[:memo]}"
+    })
+  end
+
+  def notify_email
+    NotificationMailer.with(user: @user, amount_sats: @payload[:amount])
+                      .lightning_sats_received.deliver_later
+  end
 end

app/jobs/nostr_publish_event_job.rb

@@ -0,0 +1,7 @@
+class NostrPublishEventJob < ApplicationJob
+  queue_as :nostr
+
+  def perform(event:, relay_url:)
+    NostrManager::PublishEvent.call(event: event, relay_url: relay_url)
+  end
+end

app/models/setting.rb

@@ -160,7 +160,17 @@ class Setting < RailsSettings::Base
   # Nostr
   #
 
-  field :nostr_enabled, type: :boolean, default: false
+  field :nostr_enabled, type: :boolean,
+    default: ENV["NOSTR_PRIVATE_KEY"].present?
+
+  field :nostr_private_key, type: :string,
+    default: ENV["NOSTR_PRIVATE_KEY"].presence
+
+  field :nostr_public_key, type: :string,
+    default: ENV["NOSTR_PUBLIC_KEY"].presence
+
+  field :nostr_zaps_relay_limit, type: :integer,
+    default: 12
 
   #
   # OpenCollective

app/models/user.rb

@@ -17,16 +17,15 @@ class User < ApplicationRecord
   has_one  :invitation, inverse_of: :invitee, foreign_key: 'invited_user_id'
   has_one  :inviter, through: :invitation, source: :user
   has_many :invitees, through: :invitations
-
   has_many :donations, dependent: :nullify
+  has_many :remote_storage_authorizations
+  has_many :zaps
 
   has_one  :lndhub_user, class_name: "LndhubUser", inverse_of: "user",
                          primary_key: "ln_account", foreign_key: "login"
 
   has_many :accounts, through: :lndhub_user
 
-  has_many :remote_storage_authorizations
-
   #
   # Validations
   #
@@ -143,12 +142,6 @@ class User < ApplicationRecord
     enable_service Setting.default_services
   end
 
-  def ln_create_invoice(payload)
-    lndhub = Lndhub.new
-    lndhub.authenticate self
-    lndhub.addinvoice payload
-  end
-
   def dn
     return @dn if defined?(@dn)
     @dn = Devise::LDAP::Adapter.get_dn(self.cn)

app/models/zap.rb

@@ -0,0 +1,17 @@
+class Zap < ApplicationRecord
+  belongs_to :user
+
+  def request_event
+    nostr_event_from_hash(request)
+  end
+
+  def receipt_event
+    nostr_event_from_hash(receipt)
+  end
+
+  private
+
+    def nostr_event_from_hash(hash)
+      Nostr::Event.new(**hash.symbolize_keys)
+    end
+end

app/services/lndhub_manager/create_user_invoice.rb

@@ -0,0 +1,13 @@
+module LndhubManager
+  class CreateUserInvoice < LndhubV2
+    def initialize(user:, payload:)
+      @user = user
+      @payload = payload
+    end
+
+    def call
+      authenticate @user
+      create_invoice @payload
+    end
+  end
+end

app/services/nostr_manager/create_zap_receipt.rb

@@ -0,0 +1,25 @@
+module NostrManager
+  class CreateZapReceipt < NostrManagerService
+    def initialize(zap:, paid_at:, preimage:)
+      @zap, @paid_at, @preimage = zap, paid_at, preimage
+    end
+
+    def call
+      request_tags = parse_tags(@zap.request_event.tags)
+
+      site_user.create_event(
+        kind: 9735,
+        created_at: @paid_at,
+        content: "",
+        tags: [
+          ["p", request_tags[:p].first],
+          ["e", request_tags[:e]&.first],
+          ["a", request_tags[:a]&.first],
+          ["bolt11", @zap.payment_request],
+          ["preimage", @preimage],
+          ["description", @zap.request_event.to_json]
+        ].reject { |t| t[1].nil? }
+      )
+    end
+  end
+end

app/services/nostr_manager/publish_event.rb

@@ -0,0 +1,50 @@
+module NostrManager
+  class PublishEvent < NostrManagerService
+    def initialize(event:, relay_url:)
+      relay_name = URI.parse(relay_url).host
+      @relay = Nostr::Relay.new(url: relay_url, name: relay_name)
+
+      if event.is_a?(Nostr::Event)
+        @event = event
+      else
+        @event = Nostr::Event.new(**event.symbolize_keys)
+      end
+
+      @client = Nostr::Client.new
+    end
+
+    def call
+      client, relay, event = @client, @relay, @event
+      log_prefix = "[nostr][#{relay.name}]"
+
+      thread = Thread.new do
+        client.on :connect do
+          puts "#{log_prefix} Publishing #{event.id}..."
+          client.publish event
+        end
+
+        client.on :error do |e|
+          puts "#{log_prefix} Error: #{e}"
+          puts "#{log_prefix} Closing thread..."
+          thread.exit
+        end
+
+        client.on :message do |m|
+          puts "#{log_prefix} Message: #{m}"
+          msg = JSON.parse(m) rescue []
+          if msg[0] == "OK" && msg[1] == event.id && msg[2]
+            puts "#{log_prefix} Event published. Closing thread..."
+          else
+            puts "#{log_prefix} Unexpected message from relay. Closing thread..."
+          end
+          thread.exit
+        end
+
+        puts "#{log_prefix} Connecting to #{relay.url}..."
+        client.connect relay
+      end
+
+      thread.join
+    end
+  end
+end

app/services/nostr_manager/publish_zap_receipt.rb

@@ -0,0 +1,19 @@
+module NostrManager
+  class PublishZapReceipt < NostrManagerService
+    def initialize(zap:, delayed: true)
+      @zap, @delayed = zap, delayed
+    end
+
+    def call
+      tags = parse_tags(@zap.request_event.tags)
+
+      tags[:relays].take(Setting.nostr_zaps_relay_limit).each do |relay_url|
+        if @delayed
+          NostrPublishEventJob.perform_later(event: @zap.receipt, relay_url: relay_url)
+        else
+          NostrManager::PublishEvent.call(event: @zap.receipt_event, relay_url: relay_url)
+        end
+      end
+    end
+  end
+end

app/services/nostr_manager/verify_auth.rb

@@ -7,8 +7,9 @@ module NostrManager
     end
 
     def call
-      site_given      = @event.tags.find{|t| t[0] == "site"}[1]
+      tags            = parse_tags(@event.tags)
-      challenge_given = @event.tags.find{|t| t[0] == "challenge"}[1]
+      site_given      = tags[:site].first
+      challenge_given = tags[:challenge].first
 
       site_given == @site_expected &&
       challenge_given == @challenge_expected

app/services/nostr_manager/verify_zap_request.rb

@@ -0,0 +1,51 @@
+module NostrManager
+  class VerifyZapRequest < NostrManagerService
+    def initialize(amount:, event:, lnurl: nil)
+      @amount, @event, @lnurl = amount, event, lnurl
+    end
+
+    # https://github.com/nostr-protocol/nips/blob/27fef638e2460139cc9078427a0aec0ce4470517/57.md#appendix-d-lnurl-server-zap-request-validation
+    def call
+      tags = parse_tags(@event.tags)
+
+      @event.verify_signature &&
+      @event.kind == 9734 &&
+      tags.present? &&
+      valid_p_tag?(tags[:p]) &&
+      valid_e_tag?(tags[:e]) &&
+      valid_a_tag?(tags[:a]) &&
+      valid_amount_tag?(tags[:amount]) &&
+      valid_lnurl_tag?(tags[:lnurl])
+    end
+
+    def valid_p_tag?(tag)
+      return false unless tag.present? && tag.length == 1
+      key = Nostr::PublicKey.new(tag.first) rescue nil
+      key.present?
+    end
+
+    def valid_e_tag?(tag)
+      return true unless tag.present?
+      # TODO validate format of event ID properly
+      tag.length == 1 && tag.first.is_a?(String)
+    end
+
+    def valid_a_tag?(tag)
+      return true unless tag.present?
+      # TODO validate format of event coordinate properly
+      tag.length == 1 && tag.first.is_a?(String)
+    end
+
+    def valid_amount_tag?(tag)
+      return true unless tag.present?
+      amount = tag.first
+      amount.is_a?(String) && amount.to_i == @amount
+    end
+
+    def valid_lnurl_tag?(tag)
+      return true unless tag.present?
+      # TODO validate lnurl matching recipient's lnurlp
+      tag.first.is_a?(String)
+    end
+  end
+end

app/services/nostr_manager_service.rb

@@ -1,4 +1,22 @@
 require "nostr"
 
 class NostrManagerService < ApplicationService
+  def parse_tags(tags)
+    out = {}
+    tags.each do |tag|
+      out[tag[0].to_sym] = tag[1, tag.length]
+    end
+    out
+  end
+
+  def site_keypair
+    Nostr::KeyPair.new(
+      private_key: Nostr::PrivateKey.new(Setting.nostr_private_key),
+      public_key: Nostr::PublicKey.new(Setting.nostr_public_key)
+    )
+  end
+
+  def site_user
+    Nostr::User.new(keypair: site_keypair)
+  end
 end

app/views/admin/settings/services/_nostr.html.erb

@@ -7,4 +7,27 @@
     title: "Enable Nostr integration (experimental)",
     description: "Allow adding nostr pubkeys and resolve user addresses via NIP-05"
   ) %>
+<% if Setting.nostr_enabled? %>
+  <%= render FormElements::FieldsetResettableSettingComponent.new(
+        key: :nostr_private_key,
+        type: :password,
+        title: "Private key",
+        description: "The private key of the accounts service, used when publishing events (e.g. zap receipts)"
+      ) %>
+  <%= render FormElements::FieldsetResettableSettingComponent.new(
+        key: :nostr_public_key,
+        title: "Public key",
+        description: "The corresponding public key of the accounts service"
+      ) %>
 </ul>
+</section>
+<section>
+<h3>Zaps</h3>
+<ul role="list">
+  <%= render FormElements::FieldsetResettableSettingComponent.new(
+        key: :nostr_zaps_relay_limit,
+        title: "Relay limit",
+        description: "The maximum number of relays to publish zap receipts to"
+      ) %>
+</ul>
+<% end %>

config/sidekiq.yml

@@ -3,3 +3,4 @@
   - default
   - mailers
   - remotestorage
+  - nostr

db/migrate/20240422171653_create_zaps.rb

@@ -0,0 +1,13 @@
+class CreateZaps < ActiveRecord::Migration[7.1]
+  def change
+    create_table :zaps do |t|
+      t.references :user, null: false, foreign_key: true
+      t.json :request
+      t.json :receipt, default: nil
+      t.text :payment_request
+      t.bigint :amount
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_03_16_153558) do
+ActiveRecord::Schema[7.1].define(version: 2024_04_22_171653) do
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -136,8 +136,20 @@ ActiveRecord::Schema[7.1].define(version: 2024_03_16_153558) do
     t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
   end
 
+  create_table "zaps", force: :cascade do |t|
+    t.integer "user_id", null: false
+    t.json "request"
+    t.json "receipt"
+    t.text "payment_request"
+    t.bigint "amount"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["user_id"], name: "index_zaps_on_user_id"
+  end
+
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
   add_foreign_key "remote_storage_authorizations", "app_catalog_web_apps", column: "web_app_id"
   add_foreign_key "remote_storage_authorizations", "users"
+  add_foreign_key "zaps", "users"
 end

docker-compose.yml

@@ -107,6 +107,17 @@ services:
       - minio
       - redis
 
+  nostr-relay:
+    image: pluja/strfry:latest
+    volumes:
+      - ./docker/strfry/strfry.conf:/etc/strfry.conf
+      - strfry-data:/app/strfry-db
+    networks:
+      - external_network
+      - internal_network
+    ports:
+      - "4777:7777"
+
   # phpldapadmin:
   #   image: osixia/phpldapadmin:0.9.0
   #   ports:
@@ -128,3 +139,5 @@ volumes:
     driver: local
   redis-data:
     driver: local
+  strfry-data:
+    driver: local

docker/strfry/strfry.conf

@@ -0,0 +1,138 @@
+##
+## Default strfry config
+##
+
+# Directory that contains the strfry LMDB database (restart required)
+db = "./strfry-db/"
+
+dbParams {
+    # Maximum number of threads/processes that can simultaneously have LMDB transactions open (restart required)
+    maxreaders = 256
+
+    # Size of mmap() to use when loading LMDB (default is 10TB, does *not* correspond to disk-space used) (restart required)
+    mapsize = 10995116277760
+
+    # Disables read-ahead when accessing the LMDB mapping. Reduces IO activity when DB size is larger than RAM. (restart required)
+    noReadAhead = false
+}
+
+events {
+    # Maximum size of normalised JSON, in bytes
+    maxEventSize = 65536
+
+    # Events newer than this will be rejected
+    rejectEventsNewerThanSeconds = 900
+
+    # Events older than this will be rejected
+    rejectEventsOlderThanSeconds = 94608000
+
+    # Ephemeral events older than this will be rejected
+    rejectEphemeralEventsOlderThanSeconds = 60
+
+    # Ephemeral events will be deleted from the DB when older than this
+    ephemeralEventsLifetimeSeconds = 300
+
+    # Maximum number of tags allowed
+    maxNumTags = 2000
+
+    # Maximum size for tag values, in bytes
+    maxTagValSize = 1024
+}
+
+relay {
+    # Interface to listen on. Use 0.0.0.0 to listen on all interfaces (restart required)
+    bind = "0.0.0.0"
+
+    # Port to open for the nostr websocket protocol (restart required)
+    port = 7777
+
+    # Set OS-limit on maximum number of open files/sockets (if 0, don't attempt to set) (restart required)
+    nofiles = 200000
+
+    # HTTP header that contains the client's real IP, before reverse proxying (ie x-real-ip) (MUST be all lower-case)
+    realIpHeader = ""
+
+    info {
+        # NIP-11: Name of this server. Short/descriptive (< 30 characters)
+        name = "akkounts-nostr-relay"
+
+        # NIP-11: Detailed information about relay, free-form
+        description = "Local strfry instance for akkounts development"
+
+        # NIP-11: Administrative nostr pubkey, for contact purposes
+        pubkey = ""
+
+        # NIP-11: Alternative administrative contact (email, website, etc)
+        contact = ""
+    }
+
+    # Maximum accepted incoming websocket frame size (should be larger than max event) (restart required)
+    maxWebsocketPayloadSize = 131072
+
+    # Websocket-level PING message frequency (should be less than any reverse proxy idle timeouts) (restart required)
+    autoPingSeconds = 55
+
+    # If TCP keep-alive should be enabled (detect dropped connections to upstream reverse proxy)
+    enableTcpKeepalive = false
+
+    # How much uninterrupted CPU time a REQ query should get during its DB scan
+    queryTimesliceBudgetMicroseconds = 10000
+
+    # Maximum records that can be returned per filter
+    maxFilterLimit = 500
+
+    # Maximum number of subscriptions (concurrent REQs) a connection can have open at any time
+    maxSubsPerConnection = 20
+
+    writePolicy {
+        # If non-empty, path to an executable script that implements the writePolicy plugin logic
+        plugin = ""
+    }
+
+    compression {
+        # Use permessage-deflate compression if supported by client. Reduces bandwidth, but slight increase in CPU (restart required)
+        enabled = true
+
+        # Maintain a sliding window buffer for each connection. Improves compression, but uses more memory (restart required)
+        slidingWindow = true
+    }
+
+    logging {
+        # Dump all incoming messages
+        dumpInAll = true
+
+        # Dump all incoming EVENT messages
+        dumpInEvents = false
+
+        # Dump all incoming REQ/CLOSE messages
+        dumpInReqs = false
+
+        # Log performance metrics for initial REQ database scans
+        dbScanPerf = true
+
+        # Log reason for invalid event rejection? Can be disabled to silence excessive logging
+        invalidEvents = true
+    }
+
+    numThreads {
+        # Ingester threads: route incoming requests, validate events/sigs (restart required)
+        ingester = 3
+
+        # reqWorker threads: Handle initial DB scan for events (restart required)
+        reqWorker = 3
+
+        # reqMonitor threads: Handle filtering of new events (restart required)
+        reqMonitor = 3
+
+        # negentropy threads: Handle negentropy protocol messages (restart required)
+        negentropy = 2
+    }
+
+    negentropy {
+        # Support negentropy protocol messages
+        enabled = true
+
+        # Maximum records that sync will process before returning an error
+        maxSyncEvents = 1000000
+    }
+}

lib/nostr/event_kind.rb

@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module Nostr
+  # Defines the event kinds that can be emitted by clients.
+  module EventKind
+    # The content is set to a stringified JSON object +{name: <username>, about: <string>,
+    # picture: <url, string>}+ describing the user who created the event. A relay may delete past set_metadata
+    # events once it gets a new one for the same pubkey.
+    #
+    # @return [Integer]
+    #
+    SET_METADATA = 0
+
+    # The content is set to the text content of a note (anything the user wants to say).
+    # Non-plaintext notes should instead use kind 1000-10000 as described in NIP-16.
+    #
+    # @return [Integer]
+    #
+    TEXT_NOTE = 1
+
+    # The content is set to the URL (e.g., wss://somerelay.com) of a relay the event creator wants to
+    # recommend to its followers.
+    #
+    # @return [Integer]
+    #
+    RECOMMEND_SERVER = 2
+
+    # A special event with kind 3, meaning "contact list" is defined as having a list of p tags, one for each of
+    # the followed/known profiles one is following.
+    #
+    # @return [Integer]
+    #
+    CONTACT_LIST = 3
+
+    # A special event with kind 4, meaning "encrypted direct message". An event of this kind has its +content+
+    # equal to the base64-encoded, aes-256-cbc encrypted string of anything a user wants to write, encrypted using a
+    # shared cipher generated by combining the recipient's public-key with the sender's private-key.
+    #
+    # @return [Integer]
+    #
+    ENCRYPTED_DIRECT_MESSAGE = 4
+
+    # NIP-57 Zap request
+    #
+    # @return [Integer]
+    #
+    ZAP_REQUEST = 9734
+
+    # NIP-57 Zap receipt
+    #
+    # @return [Integer]
+    #
+    ZAP_RECEIPT = 9735
+  end
+end

lib/tasks/lndhub.rake

@@ -1,3 +1,6 @@
+require "digest"
+require "pp"
+
 namespace :lndhub do
   desc "Generate wallets for all users"
   task :generate_wallets => :environment do |t, args|
@@ -22,6 +25,21 @@ namespace :lndhub do
     puts "--\nSum of user balances: #{sum} sats"
   end
 
+  desc "Create test invoice"
+  task :create_test_invoice, [:username, :amount, :description] => :environment do |t, args|
+    user = User.find_by cn: args[:username]
+    desc = args[:description]
+    hash = Digest::SHA256.hexdigest(desc)
+
+    invoice = LndhubManager::CreateUserInvoice.call(user: user, payload: {
+      "amount": args[:amount].to_i,
+      "description": desc,
+      "description_hash": hash
+    })
+
+    pp invoice
+  end
+
   desc "Migrate existing accounts to lndhub.go"
   task :migrate => :environment do |t, args|
     # user = User.find_by cn: "jimmy"

spec/factories/zaps.rb

@@ -0,0 +1,20 @@
+FactoryBot.define do
+  factory :zap do
+    user { nil }
+    request {
+      Nostr::Event.new(
+        id: "3cf02d7f0ccd9711c25098fc50b3a7ab880326e4e51cc8c7a7b59f147cff4fff",
+        pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+        created_at: 1712487443,
+        kind: 9734,
+        tags: [
+          ["relays", "wss://nostr.kosmos.org", "wss://relay.example.com"],
+          ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"]],
+        content: "",
+        sig: "e9e9bb2bac4267a107ab5c3368f504b4f11b8e3b5ae875a1d63c74d6934138d2521dc35815b6f534fc5d803cbf633736d871886368bb8f92c4ad3837a68a06f2"
+      ).to_h
+    }
+    payment_request { "lnbc1u1p3mull3pp5qw4x46ew6kjknudypyjsg8maw935tr5kkuz7t6h7pugp3pt4msyqhp5zp40yd97a028sgr9x4yxq5d57gft6vwja58e8cl0eea4uasr6apscqzpgxqyz5vqsp53m2n8h6yeflgukv5fhwm802kur6un9w8nvycl7auk67w5g2u008q9qyyssqml8rfmxyvp32qd5939qx7uu0w6ppjuujlpwsrz28m9u0dzp799hz5j72w0xm8pg97hd4hdvwh9zxaw2hewnnmzewvc550f9y3qsfaegphmk0mu" }
+    receipt { nil }
+  end
+end

spec/fixtures/lndhub/incoming-zap.json

@@ -0,0 +1,19 @@
+{
+  "id": 58,
+  "type": "incoming",
+  "user_login": "123456abcdef",
+  "amount": 21000,
+  "fee": 0,
+  "memo": "Zap for satoshi@kosmos.org",
+  "description_hash": "b1a9910724bc9c1b03b4eba2e2d78ac69a8ac7b244e6ff6d4e7391bf6893f26a",
+  "payment_request": "lnbc1u1p3mull3pp5qw4x46ew6kjknudypyjsg8maw935tr5kkuz7t6h7pugp3pt4msyqhp5zp40yd97a028sgr9x4yxq5d57gft6vwja58e8cl0eea4uasr6apscqzpgxqyz5vqsp53m2n8h6yeflgukv5fhwm802kur6un9w8nvycl7auk67w5g2u008q9qyyssqml8rfmxyvp32qd5939qx7uu0w6ppjuujlpwsrz28m9u0dzp799hz5j72w0xm8pg97hd4hdvwh9zxaw2hewnnmzewvc550f9y3qsfaegphmk0mu",
+  "destination_pubkey_hex": "024cd3be18617f39cf645851e3ba63f51fc13f0bb09e3bb25e6fd4de556486d946",
+  "r_hash": "03aa6aeb2ed5a569f1a40925041f7d7163458e96b705e5eafe0f10188575dc08",
+  "preimage": "3539663535656537343331663432653165396430623966633664656664646563",
+  "keysend": false,
+  "state": "settled",
+  "created_at": "2023-01-11T09:22:57.546364Z",
+  "expires_at": "2023-01-12T09:22:57.547209Z",
+  "updated_at": "2023-01-11T09:22:58.046236131Z",
+  "settled_at": "2023-01-11T09:22:58.046232174Z"
+}

spec/fixtures/nostr/zap_request_event.json

@@ -0,0 +1,22 @@
+{
+  "kind": 9734,
+  "created_at": 1712066899,
+  "content": "",
+  "tags": [
+    ["p", "3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d"],
+    ["amount", "21000"],
+    [
+      "relays",
+      "wss://relay.primal.net",
+      "wss://relay.snort.social",
+      "wss://nostr.wine",
+      "wss://relay.damus.io",
+      "wss://eden.nostr.land",
+      "wss://atlas.nostr.land",
+      "wss://nostr.bitcoiner.social",
+      "wss://relay.mostr.pub",
+      "wss://relay.mostr.pub/",
+      "wss://nostr-01.bolt.observer"
+    ]
+  ]
+}

spec/models/zap_spec.rb

@@ -0,0 +1,12 @@
+require 'rails_helper'
+
+RSpec.describe Zap, type: :model do
+  describe "#request_event" do
+    let(:user) { create :user, cn: 'satoshi', ou: 'kosmos.org', ln_account: 'abcdefg123456' }
+    let(:zap) { create :zap, user: user }
+
+    it "returns the stored request as a Nostr::Event" do
+      expect(zap.request_event).to be_a(Nostr::Event)
+    end
+  end
+end

spec/requests/lnurlpay_spec.rb

@@ -1,9 +1,8 @@
 require 'rails_helper'
 
 RSpec.describe "/lnurlpay", type: :request do
-
   context "Non-existent user" do
-    describe "GET /.well-known/lnurlpay/:username" do
+    describe "GET /.well-known/lnurlp/:username" do
       it "returns a 404" do
         get lightning_address_path(username: "csw")
         expect(response).to have_http_status(:not_found)
@@ -30,9 +29,10 @@ RSpec.describe "/lnurlpay", type: :request do
 
     before do
       login_as user, :scope => :user
+      Setting.nostr_enabled = false
     end
 
-    describe "GET /.well-known/lnurlpay/:username" do
+    describe "GET /.well-known/lnurlp/:username" do
       it "returns a formatted Lightning Address response" do
         get lightning_address_path(username: "satoshi")
 
@@ -45,17 +45,41 @@ RSpec.describe "/lnurlpay", type: :request do
         expect(res["minSendable"]).to be_a(Integer)
         expect(res["maxSendable"]).to be_a(Integer)
         expect(res["commentAllowed"]).to be_a(Integer)
+        expect(res["allowsNostr"]).to be_nil
+      end
+
+      context "with support for nostr zaps" do
+        before do
+          Setting.nostr_enabled = true
+        end
+
+        it "returns NIP-57 properties" do
+          get lightning_address_path(username: "satoshi")
+
+          res = JSON.parse(response.body)
+          expect(res["allowsNostr"]).to be(true)
+          expect(res["nostrPubkey"]).to eq(Setting.nostr_public_key)
+        end
       end
     end
 
     describe "GET /lnurlpay/:username/invoice" do
+      let(:invoice) {
+        {
+          "payment_hash" => "35778ccdb8319b5104e41d2043d18446bf91bcd51450b5f1cf1b6082a7cc6203",
+          "payment_request" => "lnbc210n1pnzzr6rpp5x4mcendcxxd4zp8yr5sy85vyg6ler0x4z3gttuw0rdsg9f7vvgpshp52y6nf64apaqta2kjuwp2apglewqa9fva2mada6x2mmdj20t57jdscqzzsxqyz5vqsp5a3h88efdc436wunupz293gdtvm5843yfcfc8hxm2rpdunaetl39q9qyyssq07ec02dqr4epa73ssy0lzwglw49aa9rfywlp0c7jpnf448uapsgqch79d4222xqlh8674lzddvcyptpnwqqq8vpppf8djrn8yjf53dqpzwx5kh",
+          "expires_at" => "2024-04-19T12:17:07.725314947Z"
+        }
+      }
+
       before do
-        allow_any_instance_of(User).to receive(:ln_create_invoice).and_return("lnbc50u1p3lwgknpp52g78gqya5euvzjc53fc6hkmlm2rfjhcd305tcmc0g9gaestav48sdq4gdhkven9v5sx6mmwv4ujzcqzpgxqyz5vqsp5skkz4jlqr6tkvv2g9739ygrjupc4rkqd94mc7dfpj3pgx3f6w7qs9qyyssq7mf3fzcuxlmkr9nqatcch3u8uf4gjyawe052tejz8e9fqxu4pncqk3qklt8g6ylpshg09xyjquyrgtc72vcw5cp0dzcf406apyua7dgpnfn7an")
+        allow(LndhubManager::CreateUserInvoice).to receive(:call)
+          .and_return(invoice)
       end
 
       it "returns a formatted lnurlpay response" do
         get lnurlpay_invoice_path(username: "satoshi", params: {
-          amount: 50000, comment: "Coffee time!"
+          amount: 21000, comment: "Coffee time!"
         })
 
         expect(response).to have_http_status(:ok)
@@ -64,32 +88,108 @@ RSpec.describe "/lnurlpay", type: :request do
         expect(res["status"]).to eq('OK')
         expect(res["successAction"]["tag"]).to eq('message')
         expect(res["successAction"]["message"]).to match('Thank you')
-        expect(res["pr"]).to eq("lnbc50u1p3lwgknpp52g78gqya5euvzjc53fc6hkmlm2rfjhcd305tcmc0g9gaestav48sdq4gdhkven9v5sx6mmwv4ujzcqzpgxqyz5vqsp5skkz4jlqr6tkvv2g9739ygrjupc4rkqd94mc7dfpj3pgx3f6w7qs9qyyssq7mf3fzcuxlmkr9nqatcch3u8uf4gjyawe052tejz8e9fqxu4pncqk3qklt8g6ylpshg09xyjquyrgtc72vcw5cp0dzcf406apyua7dgpnfn7an")
+        expect(res["pr"]).to eq("lnbc210n1pnzzr6rpp5x4mcendcxxd4zp8yr5sy85vyg6ler0x4z3gttuw0rdsg9f7vvgpshp52y6nf64apaqta2kjuwp2apglewqa9fva2mada6x2mmdj20t57jdscqzzsxqyz5vqsp5a3h88efdc436wunupz293gdtvm5843yfcfc8hxm2rpdunaetl39q9qyyssq07ec02dqr4epa73ssy0lzwglw49aa9rfywlp0c7jpnf448uapsgqch79d4222xqlh8674lzddvcyptpnwqqq8vpppf8djrn8yjf53dqpzwx5kh")
       end
 
-      context "amount too low" do
+      describe "amount too low" do
         it "returns an error" do
           get lnurlpay_invoice_path(username: "satoshi", params: {
             amount: 5000, comment: "Coffee time!"
           })
+
           expect(response).to have_http_status(:ok)
+
           res = JSON.parse(response.body)
           expect(res["status"]).to eq('ERROR')
           expect(res["reason"]).to eq('Invalid amount')
         end
       end
 
-      context "comment too long" do
+      describe "comment too long" do
         it "returns an error" do
           get lnurlpay_invoice_path(username: "satoshi", params: {
             amount: 5000000, comment: "Coffee time is the best time, so here's some money for you to get some. May I suggest to sample some Pacamara beans from El Salvador?"
           })
+
           expect(response).to have_http_status(:ok)
+
           res = JSON.parse(response.body)
           expect(res["status"]).to eq('ERROR')
           expect(res["reason"]).to eq('Comment too long')
         end
       end
+
+      context "zap request" do
+        before do
+          Setting.nostr_enabled = true
+        end
+
+        describe "with invalid request event" do
+          it "returns an error" do
+            get lnurlpay_invoice_path(username: "satoshi", params: {
+              amount: 2100000, nostr: { foo: "bar" }.to_json
+            })
+
+            res = JSON.parse(response.body)
+            expect(res["status"]).to eq('ERROR')
+            expect(res["reason"]).to eq('Invalid zap request')
+          end
+        end
+
+        describe "with valid request event" do
+          let(:event) {
+            Nostr::Event.new(
+              id: "3cf02d7f0ccd9711c25098fc50b3a7ab880326e4e51cc8c7a7b59f147cff4fff",
+              pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+              created_at: 1712487443,
+              kind: 9734,
+              tags: [
+                ["relays", "wss://nostr.kosmos.org", "wss://relay.example.com"],
+                ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"]],
+              content: "",
+              sig: "e9e9bb2bac4267a107ab5c3368f504b4f11b8e3b5ae875a1d63c74d6934138d2521dc35815b6f534fc5d803cbf633736d871886368bb8f92c4ad3837a68a06f2"
+            )
+          }
+
+          let(:invoice) {
+            {
+              "payment_hash" => "d6fa1d4b66587ab247d7b1f7608f2aed780a0cca021d09a30279c3dd9ff80f85",
+              "payment_request" => "lnbc210n1pnzzyvjpp56map6jmxtpaty37hk8mkpre2a4uq5rx2qgwsngcz08pam8lcp7zshp5xs7v3qlx0j0gyu9grrzx9xgews3t9vq64v30579le9z9wqr6fc5scqzzsxqyz5vqsp5kmltj5eayh47c6trwj8wdrz5nxymqp0eqwtk7k5nk6ytyz522nvs9qyyssqvkluufkp34gtzxdg0uyqcsdum2n34xz94tqr4jfwwx53czteutvj7eptz4lm5vcu0m8jqzxck484ycxzcqgqlqmpj2r3jxjlj4x6nygp8fvnag",
+              "expires_at" => "2024-04-19T12:26:58.432434748Z"
+            }
+          }
+
+          it "returns an invoice" do
+            expect(LndhubManager::CreateUserInvoice).to receive(:call)
+              .with(user: user, payload: {
+                amount: 21,
+                description: "Zap for satoshi@kosmos.org",
+                description_hash: "b1a9910724bc9c1b03b4eba2e2d78ac69a8ac7b244e6ff6d4e7391bf6893f26a"
+              })
+              .and_return(invoice)
+
+            get lnurlpay_invoice_path(username: "satoshi", params: {
+              amount: 21000, nostr: event.to_json
+            })
+
+            expect(response).to have_http_status(:ok)
+
+            res = JSON.parse(response.body)
+            expect(res["status"]).to eq('OK')
+            expect(res["pr"]).to eq(invoice["payment_request"])
+          end
+
+          it "creates a zap record" do
+            get lnurlpay_invoice_path(username: "satoshi", params: {
+              amount: 21000, nostr: event.to_json
+            })
+
+            zap = user.zaps.find_by payment_request: invoice["payment_request"]
+            expect(zap.request_event.id).to eq(event.id)
+            expect(zap.receipt).to be_nil
+          end
+        end
+      end
     end
 
     describe "GET /.well-known/keysend/:username/" do

spec/requests/webhooks_spec.rb

@@ -53,9 +53,7 @@ RSpec.describe "Webhooks", type: :request do
       let(:user) { create :user, ln_account: "123456abcdef" }
       let(:payload) { JSON.parse(File.read(File.expand_path("../fixtures/lndhub/incoming.json", File.dirname(__FILE__)))) }
 
-      before do
+      before { user.save! } #FIXME this should not be necessary
-        user.save! #FIXME this should not be necessary
-      end
 
       it "returns a 200 status" do
         post "/webhooks/lndhub", params: payload.to_json
@@ -63,9 +61,15 @@ RSpec.describe "Webhooks", type: :request do
       end
 
       it "does not send notifications by default" do
+        post "/webhooks/lndhub", params: payload.to_json
         expect(enqueued_jobs.size).to eq(0)
       end
 
+      it "does not send a zap receipt" do
+        expect(NostrManager::PublishZapReceipt).not_to receive(:call)
+        post "/webhooks/lndhub", params: payload.to_json
+      end
+
       context "notification preference set to 'xmpp'" do
         before do
           Setting.xmpp_notifications_from_address = "botka@kosmos.org"
@@ -103,5 +107,53 @@ RSpec.describe "Webhooks", type: :request do
         end
       end
     end
+
+    describe "Valid payload for zap transaction" do
+      let(:user) { create :user, ln_account: "123456abcdef" }
+      let(:zap) { create :zap, user: user }
+      let(:payload) { JSON.parse(File.read(File.expand_path("../fixtures/lndhub/incoming-zap.json", File.dirname(__FILE__)))) }
+      let(:zap_receipt) {
+        Nostr::Event.new(
+          id: "cb66278a9add37a2f1e018826327ff15304e8055ff7b910100225baf83a9d691",
+          sig: "a808d6792e21824bfddc98742b6831b1070e8b21e12aa424d2bb168a09f3a95a217d4513e803f2acb6e38404f763eb09fa07a341ee9c8c4c7d18bbe3d381eb6f",
+          pubkey: "bdd76ce2934b2f591f9fad2ebe9da18f20d2921de527494ba00eeaa0a0efadcf",
+          created_at: 1673428978,
+          kind: 9735,
+          tags: [
+            ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"],
+            ["bolt11", "lnbc1u1p3mull3pp5qw4x46ew6kjknudypyjsg8maw935tr5kkuz7t6h7pugp3pt4msyqhp5zp40yd97a028sgr9x4yxq5d57gft6vwja58e8cl0eea4uasr6apscqzpgxqyz5vqsp53m2n8h6yeflgukv5fhwm802kur6un9w8nvycl7auk67w5g2u008q9qyyssqml8rfmxyvp32qd5939qx7uu0w6ppjuujlpwsrz28m9u0dzp799hz5j72w0xm8pg97hd4hdvwh9zxaw2hewnnmzewvc550f9y3qsfaegphmk0mu"],
+            ["preimage", "3539663535656537343331663432653165396430623966633664656664646563"],
+            ["description", "{\"id\":\"3cf02d7f0ccd9711c25098fc50b3a7ab880326e4e51cc8c7a7b59f147cff4fff\",\"sig\":\"e9e9bb2bac4267a107ab5c3368f504b4f11b8e3b5ae875a1d63c74d6934138d2521dc35815b6f534fc5d803cbf633736d871886368bb8f92c4ad3837a68a06f2\",\"pubkey\":\"730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c\",\"created_at\":1712487443,\"kind\":9734,\"tags\":[[\"relays\",\"wss://nostr.kosmos.org\",\"wss://relay.example.com\"],[\"p\",\"07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3\"]],\"content\":\"\"}"]
+          ],
+          content: ""
+        )
+      }
+
+      before do
+        user.save!
+        zap.save!
+
+        allow(NostrManager::CreateZapReceipt).to receive(:call)
+          .and_return(zap_receipt)
+        allow(NostrManager::PublishZapReceipt).to receive(:call)
+          .and_return(true)
+      end
+
+      it "returns a 200 status" do
+        post "/webhooks/lndhub", params: payload.to_json
+        expect(response).to have_http_status(:ok)
+      end
+
+      it "creates and adds a zap receipt to the zap record" do
+        post "/webhooks/lndhub", params: payload.to_json
+        zap = user.zaps.first
+        expect(zap.receipt).not_to be_nil
+      end
+
+      it "publishes the zap receipt" do
+        expect(NostrManager::PublishZapReceipt).to receive(:call).with(zap: zap)
+        post "/webhooks/lndhub", params: payload.to_json
+      end
+    end
   end
 end

spec/services/nostr_manager/create_zap_receipt_spec.rb

@@ -0,0 +1,45 @@
+require 'rails_helper'
+
+RSpec.describe NostrManager::CreateZapReceipt, type: :model do
+  let(:user) { create :user, ln_account: "123456abcdef" }
+  let(:zap) { create :zap, user: user }
+
+  # before do
+  #   user.save!
+  #   zap.save!
+  # end
+
+  subject {
+    described_class.call(
+      zap: zap, paid_at: 1673428978,
+      preimage: "3539663535656537343331663432653165396430623966633664656664646563"
+    )
+  }
+
+  describe "Zap receipt" do
+    it "is a kind:9735 note" do
+      expect(subject).to be_a(Nostr::Event)
+      expect(subject.kind).to eq(9735)
+    end
+
+    it "sets created_at to when the invoice was paid" do
+      expect(subject.created_at).to eq(1673428978)
+    end
+
+    it "contains the zap recipient" do
+      expect(subject.tags.find{|t| t[0] == "p"}[1]).to eq("07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3")
+    end
+
+    it "contains the bolt11 invoice" do
+      expect(subject.tags.find{|t| t[0] == "bolt11"}[1]).to eq(zap.payment_request)
+    end
+
+    it "contains the invoice preimage" do
+      expect(subject.tags.find{|t| t[0] == "preimage"}[1]).to eq("3539663535656537343331663432653165396430623966633664656664646563")
+    end
+
+    it "contains the serialized zap request event as description" do
+      expect(subject.tags.find{|t| t[0] == "description"}[1]).to eq(zap.request_event.to_json)
+    end
+  end
+end

spec/services/nostr_manager/publish_zap_receipt_spec.rb

@@ -0,0 +1,40 @@
+require 'rails_helper'
+
+RSpec.describe NostrManager::PublishZapReceipt, type: :model do
+  let(:user) { create :user, ln_account: "123456abcdef" }
+  let(:zap) { create :zap, user: user }
+
+  describe "Default/delayed execution" do
+    it "publishes zap receipts to all requested relays" do
+      expect(NostrPublishEventJob).to receive(:perform_later)
+        .exactly(2).times.and_return(true)
+
+      described_class.call(zap: zap)
+    end
+
+    context "with a long relay list" do
+      before do
+        relays = zap.request["tags"].find { |t| t.first == "relays" }
+        [
+          "wss://aegonstargaryen.example.com", "wss://visenya.example.com",
+          "wss://rhaenys.example.com", "wss://housevelaryon.example.com",
+          "wss://aemond.example.com", "wss://jaehaerys.example.com",
+          "wss://daenerys.example.com", "wss://corlys.example.com",
+          "wss://laenor.example.com", "wss://alysanne.example.com",
+          "wss://balerion.example.com", "wss://meraxes.example.com",
+          "wss://vhaegar.example.com", "wss://vermax.example.com",
+          "wss://caraxes.example.com"
+        ].each do |url|
+          relays << url
+        end
+      end
+
+      it "limits publishing attempts to the first 12 relays" do
+        expect(NostrPublishEventJob).to receive(:perform_later)
+          .exactly(12).times.and_return(true)
+
+        described_class.call(zap: zap)
+      end
+    end
+  end
+end

spec/services/nostr_manager/verify_zap_request_spec.rb

@@ -0,0 +1,206 @@
+require 'rails_helper'
+
+RSpec.describe NostrManager::VerifyZapRequest, type: :model do
+  describe "Signature invalid" do
+    let(:event) {
+      Nostr::Event.new(
+        id: "3cf02d7f0ccd9711c25098fc50b3a7ab880326e4e51cc8c7a7b59f147cff4fff",
+        pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+        created_at: 1712487443,
+        kind: 9734,
+        tags: [
+          ["relays", "wss://nostr.kosmos.org", "wss://relay.example.com"],
+          ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"]],
+        content: "",
+        sig: "1234562bac4267a107ab5c3368f504b4f11b8e3b5ae875a1d63c74d6934138d2521dc35815b6f534fc5d803cbf633736d871886368bb8f92c4ad3837a68a06f2"
+      )
+    }
+
+    subject {
+      NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+    }
+
+    it "returns false" do
+      expect(subject).to be(false)
+    end
+  end
+
+  describe "p tag missing" do
+    let(:event) {
+      Nostr::Event.new(
+        id: "eb53c5e728b625831e318c7ab09373502dd4a41ed11c17f80f32fd1c3fe1252b",
+        pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+        created_at: 1712580669,
+        kind: 9734,
+        tags: [["relays", "wss://nostr.kosmos.org","wss://relay.example.com"]],
+        content: "",
+        sig: "8e22dcb3e91d080c9549ea0808b018194cc352dde3056a4911796d6f0239de7e1955f287c7e6769909e59ab0ffa09e307178c32128dc451823fb00102ed7e80a"
+      )
+    }
+
+    subject {
+      NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+    }
+
+    it "returns false" do
+      expect(subject).to be(false)
+    end
+  end
+
+  describe "p tag not a valid pubkey" do
+    let(:event) {
+      Nostr::Event.new(
+        id: "f2c23f038cf4d0307147d40ddceb87e34ee94acf632f5a67217a55a0b41c5d95",
+        pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+        created_at: 1712581702,
+        kind: 9734,
+        tags: [
+          ["relays", "wss://nostr.kosmos.org","wss://relay.example.com"],
+          ["p","123456abcdef"]
+        ],
+        content: "",
+        sig: "b33e6b231273d38629f5efb86325ce3b4e02a7d84dfa1f37167ca2de8392cea654ae34000fc365ddfc6e21dc8ce2365fcb000ccb9064fbbcd54c7ea4a943955b"
+      )
+    }
+
+    subject {
+      NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+    }
+
+    it "returns false" do
+      expect(subject).to be(false)
+    end
+  end
+
+  describe "Minimum valid request" do
+    let(:event) {
+      Nostr::Event.new(
+        id: "3cf02d7f0ccd9711c25098fc50b3a7ab880326e4e51cc8c7a7b59f147cff4fff",
+        pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+        created_at: 1712487443,
+        kind: 9734,
+        tags: [
+          ["relays", "wss://nostr.kosmos.org", "wss://relay.example.com"],
+          ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"]],
+        content: "",
+        sig: "e9e9bb2bac4267a107ab5c3368f504b4f11b8e3b5ae875a1d63c74d6934138d2521dc35815b6f534fc5d803cbf633736d871886368bb8f92c4ad3837a68a06f2"
+      )
+    }
+
+    subject {
+      NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+    }
+
+    it "returns true" do
+      expect(subject).to be(true)
+    end
+  end
+
+  describe "Optional amount property" do
+    describe "does not match given amount" do
+      let(:event) {
+        Nostr::Event.new(
+          id: "be3d3ba15a257546f6fbba849d4717641fd4ea9f21ae6e9278a045f31d212c5e",
+          pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+          created_at: 1712579812,
+          kind: 9734,
+          tags: [
+            ["relays", "wss://nostr.kosmos.org","wss://relay.example.com"],
+            ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"],
+            ["amount", "21000"]
+          ],
+          content: "",
+          sig: "2ca9cfd0fdaf43dd8a50ab586e83da4bd9d592def8ed198536f5e3e7aad3537818687e42d98eb61d60e33dbd848c1eecf72b68fd98376bbabdab7e029e810869"
+        )
+      }
+
+      subject {
+        NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+      }
+
+      it "returns false" do
+        expect(subject).to be(false)
+      end
+    end
+
+    describe "matches given amount" do
+      let(:event) {
+        Nostr::Event.new(
+          id: "be3d3ba15a257546f6fbba849d4717641fd4ea9f21ae6e9278a045f31d212c5e",
+          pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+          created_at: 1712579812,
+          kind: 9734,
+          tags: [
+            ["relays", "wss://nostr.kosmos.org","wss://relay.example.com"],
+            ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"],
+            ["amount", "21000"]
+          ],
+          content: "",
+          sig: "2ca9cfd0fdaf43dd8a50ab586e83da4bd9d592def8ed198536f5e3e7aad3537818687e42d98eb61d60e33dbd848c1eecf72b68fd98376bbabdab7e029e810869"
+        )
+      }
+
+      subject {
+        NostrManager::VerifyZapRequest.call(amount: 21000, event: event, lnurl: nil)
+      }
+
+      it "returns true" do
+        expect(subject).to be(true)
+      end
+    end
+  end
+
+  describe "Optional amount property" do
+    describe "does not match given amount" do
+      let(:event) {
+        Nostr::Event.new(
+          id: "be3d3ba15a257546f6fbba849d4717641fd4ea9f21ae6e9278a045f31d212c5e",
+          pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+          created_at: 1712579812,
+          kind: 9734,
+          tags: [
+            ["relays", "wss://nostr.kosmos.org","wss://relay.example.com"],
+            ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"],
+            ["amount", "21000"]
+          ],
+          content: "",
+          sig: "2ca9cfd0fdaf43dd8a50ab586e83da4bd9d592def8ed198536f5e3e7aad3537818687e42d98eb61d60e33dbd848c1eecf72b68fd98376bbabdab7e029e810869"
+        )
+      }
+
+      subject {
+        NostrManager::VerifyZapRequest.call(amount: 100000, event: event, lnurl: nil)
+      }
+
+      it "returns false" do
+        expect(subject).to be(false)
+      end
+    end
+
+    describe "matches given amount" do
+      let(:event) {
+        Nostr::Event.new(
+          id: "be3d3ba15a257546f6fbba849d4717641fd4ea9f21ae6e9278a045f31d212c5e",
+          pubkey: "730b43e6f62c2ab22710b046e481802c8ac1108ed2cb9c21dff808d57ba24b6c",
+          created_at: 1712579812,
+          kind: 9734,
+          tags: [
+            ["relays", "wss://nostr.kosmos.org","wss://relay.example.com"],
+            ["p", "07e188a1ff87ce171d517b8ed2bb7a31b1d3453a0db3b15379ec07b724d232f3"],
+            ["amount", "21000"]
+          ],
+          content: "",
+          sig: "2ca9cfd0fdaf43dd8a50ab586e83da4bd9d592def8ed198536f5e3e7aad3537818687e42d98eb61d60e33dbd848c1eecf72b68fd98376bbabdab7e029e810869"
+        )
+      }
+
+      subject {
+        NostrManager::VerifyZapRequest.call(amount: 21000, event: event, lnurl: nil)
+      }
+
+      it "returns true" do
+        expect(subject).to be(true)
+      end
+    end
+  end
+end