diff --git a/README.md b/README.md
index d50ebc8..463b629 100644
--- a/README.md
+++ b/README.md
@@ -47,13 +47,13 @@ errors in a certain environment, just don't set the DSN in that environment!
 
 ```bash
 # Set your SENTRY_DSN environment variable.
-export SENTRY_DSN=https://public:secret@example.com/project-id
+export SENTRY_DSN=https://public@example.com/project-id
 ```
 
 ```crystal
 # Or you can configure the client in the code (not recommended - keep your DSN secret!)
 Raven.configure do |config|
-  config.dsn = "https://public:secret@example.com/project-id"
+  config.dsn = "https://public@example.com/project-id"
 end
 ```
 
diff --git a/shard.yml b/shard.yml
index 0df4777..f7256b4 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,5 +1,5 @@
 name: raven
-version: 1.1.0
+version: 1.2.0
 
 authors:
   - Sijawusz Pur Rahnama <sija@sija.pl>
@@ -7,14 +7,15 @@ authors:
 dependencies:
   any_hash:
     github: Sija/any_hash.cr
-    version: 0.2.2
+    version: ~> 0.2.2
 
 development_dependencies:
   timecop:
-    github: TobiasGSmollett/timecop.cr
+    github: crystal-community/timecop.cr
+    version: ~> 0.2.0
   ameba:
     github: veelenga/ameba
-    version: 0.8.0
+    version: ~> 0.9.0
 
 targets:
   crash_handler:
diff --git a/spec/raven/breadcrumb_buffer_spec.cr b/spec/raven/breadcrumb_buffer_spec.cr
index bff6136..4b2a7a4 100644
--- a/spec/raven/breadcrumb_buffer_spec.cr
+++ b/spec/raven/breadcrumb_buffer_spec.cr
@@ -31,6 +31,20 @@ describe Raven::BreadcrumbBuffer do
     end
   end
 
+  it "records breadcrumbs w/a splat" do
+    with_breadcrumb_buffer do |breadcrumbs|
+      breadcrumbs.record(message: "test")
+      breadcrumbs.members.first.message.should eq("test")
+    end
+  end
+
+  it "records breadcrumbs w/a NamedTuple" do
+    with_breadcrumb_buffer do |breadcrumbs|
+      breadcrumbs.record({message: "test"})
+      breadcrumbs.members.first.message.should eq("test")
+    end
+  end
+
   it "allows peeking" do
     with_breadcrumb_buffer do |breadcrumbs|
       breadcrumbs.peek.should be_nil
diff --git a/spec/raven/instance_spec.cr b/spec/raven/instance_spec.cr
index 4b848ec..a604ac0 100644
--- a/spec/raven/instance_spec.cr
+++ b/spec/raven/instance_spec.cr
@@ -15,7 +15,7 @@ end
 private class InstanceTest < Raven::Instance
   getter last_sent_event : Raven::Event?
 
-  def send_event(event)
+  def send_event(event, hint = nil)
     super.tap do
       @last_sent_event = event
     end
diff --git a/src/crash_handler.cr b/src/crash_handler.cr
index b07c6c4..7a78dd6 100644
--- a/src/crash_handler.cr
+++ b/src/crash_handler.cr
@@ -148,7 +148,7 @@ module Raven
       {output.to_s.chomp, error.to_s.chomp}
     end
 
-    def run : Void
+    def run : Nil
       configure!
       @started_at = Time.monotonic
 
diff --git a/src/raven/breadcrumb.cr b/src/raven/breadcrumb.cr
index 60eaa79..921715b 100644
--- a/src/raven/breadcrumb.cr
+++ b/src/raven/breadcrumb.cr
@@ -1,5 +1,7 @@
 module Raven
   class Breadcrumb
+    include Mixin::InitializeWith
+
     # The type of breadcrumb. The default type is `Type::DEFAULT` which indicates
     # no specific handling. Other types are currently:
     # - `Type::HTTP` for HTTP requests and
@@ -58,8 +60,9 @@ module Raven
     # are unsupported by the type are rendered as a key/value table.
     any_json_property :data
 
-    def initialize
+    def initialize(**options)
       @timestamp = Time.now
+      initialize_with **options
     end
 
     def to_hash
@@ -74,5 +77,3 @@ module Raven
     end
   end
 end
-
-require "./breadcrumbs/*"
diff --git a/src/raven/breadcrumb_buffer.cr b/src/raven/breadcrumb_buffer.cr
index ceaeb70..572ab75 100644
--- a/src/raven/breadcrumb_buffer.cr
+++ b/src/raven/breadcrumb_buffer.cr
@@ -23,15 +23,23 @@ module Raven
       @buffer = Array(Breadcrumb?).new(size, nil)
     end
 
-    def record(crumb : Breadcrumb) : Void
+    def record(crumb : Breadcrumb) : Nil
       @buffer.shift
       @buffer << crumb
     end
 
-    def record(crumb : Breadcrumb? = nil) : Void
-      crumb ||= Breadcrumb.new
+    def record(**opts) : Nil
+      crumb = Breadcrumb.new(**opts)
       yield crumb
-      self.record crumb
+      record crumb
+    end
+
+    def record(**opts) : Nil
+      record(**opts) { }
+    end
+
+    def record(opts : NamedTuple) : Nil
+      record(**opts)
     end
 
     def members : Array(Breadcrumb)
diff --git a/src/raven/client.cr b/src/raven/client.cr
index 9f4e6a3..3b96189 100644
--- a/src/raven/client.cr
+++ b/src/raven/client.cr
@@ -38,7 +38,16 @@ module Raven
       transport.send_feedback(event_id, data)
     end
 
-    def send_event(event : Event | Event::HashType)
+    def send_event(event : Event | Event::HashType, hint : Event::Hint? = nil)
+      if event.is_a?(Event)
+        configuration.before_send.try do |before_send|
+          event = before_send.call(event, hint)
+          unless event
+            logger.info "Discarded event because before_send returned nil"
+            return
+          end
+        end
+      end
       event = event.is_a?(Event) ? event.to_hash : event
       unless @state.should_try?
         failed_send nil, event
diff --git a/src/raven/client_state.cr b/src/raven/client_state.cr
index 6ac2960..c900b40 100644
--- a/src/raven/client_state.cr
+++ b/src/raven/client_state.cr
@@ -27,18 +27,18 @@ module Raven
       false
     end
 
-    def failure(retry_after = nil) : Void
+    def failure(retry_after = nil) : Nil
       @status = Status::ERROR
       @retry_number += 1
       @last_check = Time.now
       @retry_after = retry_after
     end
 
-    def success : Void
+    def success : Nil
       reset
     end
 
-    def reset : Void
+    def reset : Nil
       @status = Status::ONLINE
       @retry_number = 0
       @last_check = nil
diff --git a/src/raven/configuration.cr b/src/raven/configuration.cr
index d289c18..8fb8e3d 100644
--- a/src/raven/configuration.cr
+++ b/src/raven/configuration.cr
@@ -50,7 +50,7 @@ module Raven
     property async : Proc(Event, Nil)?
 
     # ditto
-    def async=(block : Proc(Event, _))
+    def async=(block : Event -> _)
       @async = ->(event : Event) {
         block.call(event)
         nil
@@ -237,13 +237,37 @@ module Raven
     property transport_failure_callback : Proc(Event::HashType, Nil)?
 
     # ditto
-    def transport_failure_callback=(block : Proc(Event::HashType, _))
+    def transport_failure_callback=(block : Event::HashType -> _)
       @transport_failure_callback = ->(event : Event::HashType) {
         block.call(event)
         nil
       }
     end
 
+    # Optional `Proc`, called before sending an event to the server:
+    #
+    # ```
+    # ->(event : Raven::Event, hint : Raven::Event::Hint?) {
+    #   if hint.try(&.exception).try(&.message) =~ /database unavailable/i
+    #     event.fingerprint << "database-unavailable"
+    #   end
+    #   event
+    # }
+    # ```
+    def before_send=(block : Event, Event::Hint? -> _)
+      @before_send = ->(event : Event, hint : Event::Hint?) {
+        block.call(event, hint).as(Event?)
+      }
+    end
+
+    # ditto
+    def before_send(&block : Event, Event::Hint? -> _)
+      self.before_send = block
+    end
+
+    # ditto
+    property before_send : Proc(Event, Event::Hint?, Event?)?
+
     # Errors object - an `Array` containing error messages.
     getter errors = [] of String
 
@@ -257,14 +281,14 @@ module Raven
       @release = detect_release
       @server_name = server_name_from_env
 
-      # try runtime ENV variable first
-      if dsn = ENV["SENTRY_DSN"]?
-        self.dsn = dsn
-      end
-      # then try compile-time ENV variable
-      # overwrites runtime if set
+      # try compile-time ENV variable
       {% if dsn = env("SENTRY_DSN") %}
         self.dsn = {{dsn}}
+      {% else %}
+        # try runtime ENV variable
+        if dsn = ENV["SENTRY_DSN"]?
+          self.dsn = dsn
+        end
       {% end %}
     end
 
@@ -314,11 +338,10 @@ module Raven
       File.directory?("/etc/heroku")
     end
 
-    private def heroku_dyno_metadata_message
+    private HEROKU_DYNO_METADATA_MESSAGE =
       "You are running on Heroku but haven't enabled Dyno Metadata. " \
       "For Sentry's release detection to work correctly, please run " \
       "`heroku labs:enable runtime-dyno-metadata`"
-    end
 
     private def detect_release_from_heroku
       return unless running_on_heroku?
@@ -326,7 +349,7 @@ module Raven
       if commit = ENV["HEROKU_SLUG_COMMIT"]?
         return commit
       end
-      logger.warn(heroku_dyno_metadata_message)
+      logger.warn(HEROKU_DYNO_METADATA_MESSAGE)
       nil
     end
 
diff --git a/src/raven/event.cr b/src/raven/event.cr
index 801a3c1..6522d94 100644
--- a/src/raven/event.cr
+++ b/src/raven/event.cr
@@ -13,6 +13,9 @@ module Raven
       FATAL
     end
 
+    # Structure passed to `Configuration#before_send` callback.
+    record Hint, exception : Exception?, message : String?
+
     # See Sentry server default limits at
     # https://github.com/getsentry/sentry/blob/master/src/sentry/conf/server.py
     MAX_MESSAGE_SIZE_IN_BYTES = 1024 * 8
diff --git a/src/raven/instance.cr b/src/raven/instance.cr
index 61c75e1..794169b 100644
--- a/src/raven/instance.cr
+++ b/src/raven/instance.cr
@@ -103,8 +103,8 @@ module Raven
     # event = Raven::Event.new(message: "An error")
     # Raven.send_event(event)
     # ```
-    def send_event(event)
-      client.send_event(event)
+    def send_event(event, hint = nil)
+      client.send_event(event, hint)
     end
 
     @last_event_id_mutex = Mutex.new
@@ -131,16 +131,22 @@ module Raven
       end
       Event.from(obj, configuration: configuration, context: context).tap do |event|
         event.initialize_with **options
-        yield event
+        hint =
+          if obj.is_a?(String)
+            Event::Hint.new(exception: nil, message: obj)
+          else
+            Event::Hint.new(exception: obj, message: nil)
+          end
+        yield event, hint
         if async = configuration.async
           begin
             async.call(event)
           rescue ex
             logger.error "Async event sending failed: #{ex.message}"
-            send_event(event)
+            send_event(event, hint)
           end
         else
-          send_event(event)
+          send_event(event, hint)
         end
         @last_event_id_mutex.synchronize do
           @last_event_id = event.id
diff --git a/src/raven/breadcrumbs/logger.cr b/src/raven/integrations/kernel/logger.cr
similarity index 100%
rename from src/raven/breadcrumbs/logger.cr
rename to src/raven/integrations/kernel/logger.cr
diff --git a/src/raven/integrations/kernel/spawn.cr b/src/raven/integrations/kernel/spawn.cr
index e16aca5..ebda53d 100644
--- a/src/raven/integrations/kernel/spawn.cr
+++ b/src/raven/integrations/kernel/spawn.cr
@@ -1,5 +1,4 @@
 def spawn(*, name : String? = nil, &block)
-  # ameba:disable Style/RedundantBegin
   wrapped_block = ->{
     begin
       block.call
diff --git a/src/raven/transports/dummy.cr b/src/raven/transports/dummy.cr
index a3ee4d8..409c4c7 100644
--- a/src/raven/transports/dummy.cr
+++ b/src/raven/transports/dummy.cr
@@ -6,7 +6,7 @@ module Raven
     def send_event(auth_header, data, **options)
       events << {
         auth_header: auth_header,
-        data:        data,
+        data:        data.to_s,
         options:     options,
       }.to_any_json
     end
diff --git a/src/raven/version.cr b/src/raven/version.cr
index b74f44f..8f01e62 100644
--- a/src/raven/version.cr
+++ b/src/raven/version.cr
@@ -1,3 +1,3 @@
 module Raven
-  VERSION = "1.1.0"
+  VERSION = "1.2.0"
 end