diff --git a/temporalio/Rakefile b/temporalio/Rakefile
index 73972bc2..81523c4b 100644
--- a/temporalio/Rakefile
+++ b/temporalio/Rakefile
@@ -94,7 +94,7 @@ Rake::Task[:build].enhance([:copy_parent_files]) do
 end
 
 task :rust_lint do
-  sh 'cargo', 'clippy', '--', '-Dwarnings'
+  sh 'cargo', 'clippy', '-p', 'temporalio_bridge', '--no-deps', '--', '-Dwarnings'
   sh 'cargo', 'fmt', '--check'
 end
 
diff --git a/temporalio/extra/proto_gen.rb b/temporalio/extra/proto_gen.rb
index 68ac2206..22985407 100644
--- a/temporalio/extra/proto_gen.rb
+++ b/temporalio/extra/proto_gen.rb
@@ -95,6 +95,7 @@ def generate_import_helper_files
         require 'temporalio/api/errordetails/v1/message'
         require 'temporalio/api/export/v1/message'
         require 'temporalio/api/operatorservice'
+        require 'temporalio/api/sdk/v1/workflow_metadata'
         require 'temporalio/api/workflowservice'
 
         module Temporalio
diff --git a/temporalio/lib/temporalio/api.rb b/temporalio/lib/temporalio/api.rb
index 621b1a18..a1ee262d 100644
--- a/temporalio/lib/temporalio/api.rb
+++ b/temporalio/lib/temporalio/api.rb
@@ -5,6 +5,7 @@
 require 'temporalio/api/errordetails/v1/message'
 require 'temporalio/api/export/v1/message'
 require 'temporalio/api/operatorservice'
+require 'temporalio/api/sdk/v1/workflow_metadata'
 require 'temporalio/api/workflowservice'
 
 module Temporalio
diff --git a/temporalio/lib/temporalio/client.rb b/temporalio/lib/temporalio/client.rb
index 51fdb2d8..696aba55 100644
--- a/temporalio/lib/temporalio/client.rb
+++ b/temporalio/lib/temporalio/client.rb
@@ -194,6 +194,12 @@ def operator_service
     # @param args [Array<Object>] Arguments to the workflow.
     # @param id [String] Unique identifier for the workflow execution.
     # @param task_queue [String] Task queue to run the workflow on.
+    # @param static_summary [String, nil] Fixed single-line summary for this workflow execution that may appear in
+    #   CLI/UI. This can be in single-line Temporal markdown format. This is currently experimental.
+    # @param static_details [String, nil] Fixed details for this workflow execution that may appear in CLI/UI. This can
+    #   be in Temporal markdown format and can be multiple lines. This is a fixed value on the workflow that cannot be
+    #   updated. For details that can be updated, use {Workflow.current_details=} within the workflow. This is currently
+    #   experimental.
     # @param execution_timeout [Float, nil] Total workflow execution timeout in seconds including retries and continue
     #   as new.
     # @param run_timeout [Float, nil] Timeout of a single workflow run in seconds.
@@ -220,6 +226,8 @@ def start_workflow(
       *args,
       id:,
       task_queue:,
+      static_summary: nil,
+      static_details: nil,
       execution_timeout: nil,
       run_timeout: nil,
       task_timeout: nil,
@@ -238,6 +246,8 @@ def start_workflow(
                              args:,
                              workflow_id: id,
                              task_queue:,
+                             static_summary:,
+                             static_details:,
                              execution_timeout:,
                              run_timeout:,
                              task_timeout:,
@@ -260,6 +270,12 @@ def start_workflow(
     # @param args [Array<Object>] Arguments to the workflow.
     # @param id [String] Unique identifier for the workflow execution.
     # @param task_queue [String] Task queue to run the workflow on.
+    # @param static_summary [String, nil] Fixed single-line summary for this workflow execution that may appear in
+    #   CLI/UI. This can be in single-line Temporal markdown format. This is currently experimental.
+    # @param static_details [String, nil] Fixed details for this workflow execution that may appear in CLI/UI. This can
+    #   be in Temporal markdown format and can be multiple lines. This is a fixed value on the workflow that cannot be
+    #   updated. For details that can be updated, use {Workflow.current_details=} within the workflow. This is currently
+    #   experimental.
     # @param execution_timeout [Float, nil] Total workflow execution timeout in seconds including retries and continue
     #   as new.
     # @param run_timeout [Float, nil] Timeout of a single workflow run in seconds.
@@ -287,6 +303,8 @@ def execute_workflow(
       *args,
       id:,
       task_queue:,
+      static_summary: nil,
+      static_details: nil,
       execution_timeout: nil,
       run_timeout: nil,
       task_timeout: nil,
@@ -305,6 +323,8 @@ def execute_workflow(
         *args,
         id:,
         task_queue:,
+        static_summary:,
+        static_details:,
         execution_timeout:,
         run_timeout:,
         task_timeout:,
diff --git a/temporalio/lib/temporalio/client/interceptor.rb b/temporalio/lib/temporalio/client/interceptor.rb
index 0a556624..5a3ced80 100644
--- a/temporalio/lib/temporalio/client/interceptor.rb
+++ b/temporalio/lib/temporalio/client/interceptor.rb
@@ -23,6 +23,8 @@ def intercept_client(next_interceptor)
         :args,
         :workflow_id,
         :task_queue,
+        :static_summary,
+        :static_details,
         :execution_timeout,
         :run_timeout,
         :task_timeout,
diff --git a/temporalio/lib/temporalio/client/schedule.rb b/temporalio/lib/temporalio/client/schedule.rb
index 0da47070..95e71e04 100644
--- a/temporalio/lib/temporalio/client/schedule.rb
+++ b/temporalio/lib/temporalio/client/schedule.rb
@@ -167,6 +167,8 @@ def _to_proto(data_converter)
           :args,
           :id,
           :task_queue,
+          :static_summary,
+          :static_details,
           :execution_timeout,
           :run_timeout,
           :task_timeout,
@@ -186,6 +188,14 @@ def _to_proto(data_converter)
         #   @return [String] Unique identifier for the workflow execution.
         # @!attribute task_queue
         #   @return [String] Task queue to run the workflow on.
+        # @!attribute static_summary
+        #   @return [String, nil] Fixed single-line summary for this workflow execution that may appear in CLI/UI.
+        #     This can be in single-line Temporal markdown format. This is currently experimental.
+        # @!attribute static_details
+        #   @return [String, nil] Fixed details for this workflow execution that may appear in CLI/UI. This can be in
+        #     Temporal markdown format and can be multiple lines. This is a fixed value on the workflow that cannot be
+        #     updated. For details that can be updated, use {Workflow.current_details=} within the workflow. This is
+        #     currently experimental.
         # @!attribute execution_timeout
         #   @return [Float, nil] Total workflow execution timeout in seconds including retries and continue as new.
         # @!attribute run_timeout
@@ -212,6 +222,12 @@ class << self
             # @param args [Array<Object>] Arguments to the workflow.
             # @param id [String] Unique identifier for the workflow execution.
             # @param task_queue [String] Task queue to run the workflow on.
+            # @param static_summary [String, nil] Fixed single-line summary for this workflow execution that may appear
+            #   in CLI/UI. This can be in single-line Temporal markdown format. This is currently experimental.
+            # @param static_details [String, nil] Fixed details for this workflow execution that may appear in CLI/UI.
+            #   This can be in Temporal markdown format and can be multiple lines. This is a fixed value on the workflow
+            #   that cannot be updated. For details that can be updated, use {Workflow.current_details=} within the
+            #   workflow. This is currently experimental.
             # @param execution_timeout [Float, nil] Total workflow execution timeout in seconds including retries and
             #   continue as new.
             # @param run_timeout [Float, nil] Timeout of a single workflow run in seconds.
@@ -225,6 +241,8 @@ def new(
               *args,
               id:,
               task_queue:,
+              static_summary: nil,
+              static_details: nil,
               execution_timeout: nil,
               run_timeout: nil,
               task_timeout: nil,
@@ -238,6 +256,8 @@ def new(
                 args:,
                 id:,
                 task_queue:,
+                static_summary:,
+                static_details:,
                 execution_timeout:,
                 run_timeout:,
                 task_timeout:,
@@ -251,11 +271,14 @@ def new(
 
           # @!visibility private
           def self._from_proto(raw_info, data_converter)
+            (summary, details) = Internal::ProtoUtils.from_user_metadata(raw_info.user_metadata, data_converter)
             StartWorkflow.new(
               raw_info.workflow_type.name,
               *data_converter.from_payloads(raw_info.input),
               id: raw_info.workflow_id,
               task_queue: raw_info.task_queue.name,
+              static_summary: summary,
+              static_details: details,
               execution_timeout: Internal::ProtoUtils.duration_to_seconds(raw_info.workflow_execution_timeout),
               run_timeout: Internal::ProtoUtils.duration_to_seconds(raw_info.workflow_run_timeout),
               task_timeout: Internal::ProtoUtils.duration_to_seconds(raw_info.workflow_task_timeout),
@@ -280,7 +303,8 @@ def _to_proto(data_converter)
                 retry_policy: retry_policy&._to_proto,
                 memo: Internal::ProtoUtils.memo_to_proto(memo, data_converter),
                 search_attributes: search_attributes&._to_proto,
-                header: Internal::ProtoUtils.headers_to_proto(headers, data_converter)
+                header: Internal::ProtoUtils.headers_to_proto(headers, data_converter),
+                user_metadata: Internal::ProtoUtils.to_user_metadata(static_summary, static_details, data_converter)
               )
             )
           end
diff --git a/temporalio/lib/temporalio/client/with_start_workflow_operation.rb b/temporalio/lib/temporalio/client/with_start_workflow_operation.rb
index 478227e7..8d667a10 100644
--- a/temporalio/lib/temporalio/client/with_start_workflow_operation.rb
+++ b/temporalio/lib/temporalio/client/with_start_workflow_operation.rb
@@ -12,6 +12,8 @@ class WithStartWorkflowOperation
         :args,
         :id,
         :task_queue,
+        :static_summary,
+        :static_details,
         :execution_timeout,
         :run_timeout,
         :task_timeout,
@@ -41,6 +43,8 @@ def initialize(
         *args,
         id:,
         task_queue:,
+        static_summary: nil,
+        static_details: nil,
         execution_timeout: nil,
         run_timeout: nil,
         task_timeout: nil,
@@ -58,6 +62,8 @@ def initialize(
           args:,
           id:,
           task_queue:,
+          static_summary:,
+          static_details:,
           execution_timeout:,
           run_timeout:,
           task_timeout:,
diff --git a/temporalio/lib/temporalio/client/workflow_execution.rb b/temporalio/lib/temporalio/client/workflow_execution.rb
index f9d7ecc2..7f3d30d3 100644
--- a/temporalio/lib/temporalio/client/workflow_execution.rb
+++ b/temporalio/lib/temporalio/client/workflow_execution.rb
@@ -93,6 +93,25 @@ class Description < WorkflowExecution
         def initialize(raw_description, data_converter)
           super(raw_description.workflow_execution_info, data_converter)
           @raw_description = raw_description
+          @data_converter = data_converter
+        end
+
+        # @return [String, nil] Static summary configured on the workflow. This is currently experimental.
+        def static_summary
+          user_metadata.first
+        end
+
+        # @return [String, nil] Static details configured on the workflow. This is currently experimental.
+        def static_details
+          user_metadata.last
+        end
+
+        private
+
+        def user_metadata
+          @user_metadata ||= Internal::ProtoUtils.from_user_metadata(
+            @raw_description.execution_config&.user_metadata, @data_converter
+          )
         end
       end
     end
diff --git a/temporalio/lib/temporalio/internal/client/implementation.rb b/temporalio/lib/temporalio/internal/client/implementation.rb
index 174afc1b..06242a53 100644
--- a/temporalio/lib/temporalio/internal/client/implementation.rb
+++ b/temporalio/lib/temporalio/internal/client/implementation.rb
@@ -69,6 +69,9 @@ def start_workflow(input)
             search_attributes: input.search_attributes&._to_proto,
             workflow_start_delay: ProtoUtils.seconds_to_duration(input.start_delay),
             request_eager_execution: input.request_eager_start,
+            user_metadata: ProtoUtils.to_user_metadata(
+              input.static_summary, input.static_details, @client.data_converter
+            ),
             header: ProtoUtils.headers_to_proto(input.headers, @client.data_converter)
           )
 
@@ -319,6 +322,9 @@ def _start_workflow_request_from_with_start_options(klass, start_options)
             memo: ProtoUtils.memo_to_proto(start_options.memo, @client.data_converter),
             search_attributes: start_options.search_attributes&._to_proto,
             workflow_start_delay: ProtoUtils.seconds_to_duration(start_options.start_delay),
+            user_metadata: ProtoUtils.to_user_metadata(
+              start_options.static_summary, start_options.static_details, @client.data_converter
+            ),
             header: ProtoUtils.headers_to_proto(start_options.headers, @client.data_converter)
           )
         end
diff --git a/temporalio/lib/temporalio/internal/proto_utils.rb b/temporalio/lib/temporalio/internal/proto_utils.rb
index 172617a1..6ebfa33c 100644
--- a/temporalio/lib/temporalio/internal/proto_utils.rb
+++ b/temporalio/lib/temporalio/internal/proto_utils.rb
@@ -122,6 +122,22 @@ def self.reserved_name?(name)
         name.start_with?('__temporal_') || name == '__stack_trace' || name == '__enhanced_stack_trace'
       end
 
+      def self.to_user_metadata(summary, details, converter)
+        return nil if (!summary || summary.empty?) && (!details || details.empty?)
+
+        metadata = Temporalio::Api::Sdk::V1::UserMetadata.new
+        metadata.summary = converter.to_payload(summary) if summary && !summary.empty?
+        metadata.details = converter.to_payload(details) if details && !details.empty?
+        metadata
+      end
+
+      def self.from_user_metadata(metadata, converter)
+        [
+          (converter.from_payload(metadata.summary) if metadata&.summary), #: String?
+          (converter.from_payload(metadata.details) if metadata&.details) #: String?
+        ]
+      end
+
       class LazyMemo
         def initialize(raw_memo, converter)
           @raw_memo = raw_memo
diff --git a/temporalio/lib/temporalio/internal/worker/workflow_instance.rb b/temporalio/lib/temporalio/internal/worker/workflow_instance.rb
index 1add6a16..9840dc04 100644
--- a/temporalio/lib/temporalio/internal/worker/workflow_instance.rb
+++ b/temporalio/lib/temporalio/internal/worker/workflow_instance.rb
@@ -56,6 +56,7 @@ def self.new_completion_with_failure(run_id:, error:, failure_converter:, payloa
                     :failure_converter, :cancellation, :continue_as_new_suggested, :current_history_length,
                     :current_history_size, :replaying, :random, :signal_handlers, :query_handlers, :update_handlers,
                     :context_frozen
+        attr_accessor :current_details
 
         def initialize(details)
           # Initialize general state
@@ -386,9 +387,10 @@ def apply_signal(job)
         def apply_query(job)
           schedule do
             # If it's a built-in, run it without interceptors, otherwise do normal behavior
-            # TODO(cretz): __temporal_workflow_metadata
             result = if job.query_type == '__stack_trace'
                        scheduler.stack_trace
+                     elsif job.query_type == '__temporal_workflow_metadata'
+                       workflow_metadata
                      else
                        # Get query definition, falling back to dynamic if not present and not reserved
                        defn = query_handlers[job.query_type]
@@ -678,6 +680,30 @@ def convert_args(payload_array:, method_name:, raw_args:, ignore_first_param: fa
           end
         end
 
+        def workflow_metadata
+          Temporalio::Api::Sdk::V1::WorkflowMetadata.new(
+            definition: Temporalio::Api::Sdk::V1::WorkflowDefinition.new(
+              type: info.workflow_type,
+              query_definitions: query_handlers.values.map do |defn|
+                Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+                  name: defn.name || '', description: defn.description || ''
+                )
+              end,
+              signal_definitions: signal_handlers.values.map do |defn|
+                Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+                  name: defn.name || '', description: defn.description || ''
+                )
+              end,
+              update_definitions: update_handlers.values.map do |defn|
+                Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+                  name: defn.name || '', description: defn.description || ''
+                )
+              end
+            ),
+            current_details: current_details || ''
+          )
+        end
+
         def scoped_logger_info
           @scoped_logger_info ||= {
             attempt: info.attempt,
diff --git a/temporalio/lib/temporalio/internal/worker/workflow_instance/context.rb b/temporalio/lib/temporalio/internal/worker/workflow_instance/context.rb
index eb094970..b66b6827 100644
--- a/temporalio/lib/temporalio/internal/worker/workflow_instance/context.rb
+++ b/temporalio/lib/temporalio/internal/worker/workflow_instance/context.rb
@@ -32,6 +32,16 @@ def continue_as_new_suggested
             @instance.continue_as_new_suggested
           end
 
+          def current_details
+            @instance.current_details || ''
+          end
+
+          def current_details=(details)
+            raise 'Details must be a String' unless details.nil? || details.is_a?(String)
+
+            @instance.current_details = (details || '')
+          end
+
           def current_history_length
             @instance.current_history_length
           end
@@ -52,6 +62,7 @@ def execute_activity(
             activity,
             *args,
             task_queue:,
+            summary:,
             schedule_to_close_timeout:,
             schedule_to_start_timeout:,
             start_to_close_timeout:,
@@ -67,6 +78,7 @@ def execute_activity(
                 activity:,
                 args:,
                 task_queue: task_queue || info.task_queue,
+                summary:,
                 schedule_to_close_timeout:,
                 schedule_to_start_timeout:,
                 start_to_close_timeout:,
@@ -191,6 +203,8 @@ def start_child_workflow(
             *args,
             id:,
             task_queue:,
+            static_summary:,
+            static_details:,
             cancellation:,
             cancellation_type:,
             parent_close_policy:,
@@ -209,6 +223,8 @@ def start_child_workflow(
                 args:,
                 id:,
                 task_queue:,
+                static_summary:,
+                static_details:,
                 cancellation:,
                 cancellation_type:,
                 parent_close_policy:,
diff --git a/temporalio/lib/temporalio/internal/worker/workflow_instance/outbound_implementation.rb b/temporalio/lib/temporalio/internal/worker/workflow_instance/outbound_implementation.rb
index 6dc3ee50..5825b602 100644
--- a/temporalio/lib/temporalio/internal/worker/workflow_instance/outbound_implementation.rb
+++ b/temporalio/lib/temporalio/internal/worker/workflow_instance/outbound_implementation.rb
@@ -84,7 +84,8 @@ def execute_activity(input)
                     retry_policy: input.retry_policy&._to_proto,
                     cancellation_type: input.cancellation_type,
                     do_not_eagerly_execute: input.disable_eager_execution
-                  )
+                  ),
+                  user_metadata: ProtoUtils.to_user_metadata(input.summary, nil, @instance.payload_converter)
                 )
               )
               seq
@@ -300,7 +301,8 @@ def sleep(input)
                 start_timer: Bridge::Api::WorkflowCommands::StartTimer.new(
                   seq:,
                   start_to_fire_timeout: ProtoUtils.seconds_to_duration(duration)
-                )
+                ),
+                user_metadata: ProtoUtils.to_user_metadata(input.summary, nil, @instance.payload_converter)
               )
             )
             @instance.pending_timers[seq] = Fiber.current
@@ -354,6 +356,9 @@ def start_child_workflow(input)
                   memo: ProtoUtils.memo_to_proto_hash(input.memo, @instance.payload_converter),
                   search_attributes: input.search_attributes&._to_proto_hash,
                   cancellation_type: input.cancellation_type
+                ),
+                user_metadata: ProtoUtils.to_user_metadata(
+                  input.static_summary, input.static_details, @instance.payload_converter
                 )
               )
             )
diff --git a/temporalio/lib/temporalio/worker/interceptor.rb b/temporalio/lib/temporalio/worker/interceptor.rb
index b5acc4a2..0662c4a5 100644
--- a/temporalio/lib/temporalio/worker/interceptor.rb
+++ b/temporalio/lib/temporalio/worker/interceptor.rb
@@ -206,6 +206,7 @@ def handle_update(input)
           :activity,
           :args,
           :task_queue,
+          :summary,
           :schedule_to_close_timeout,
           :schedule_to_start_timeout,
           :start_to_close_timeout,
@@ -270,6 +271,8 @@ def handle_update(input)
           :args,
           :id,
           :task_queue,
+          :static_summary,
+          :static_details,
           :cancellation,
           :cancellation_type,
           :parent_close_policy,
diff --git a/temporalio/lib/temporalio/workflow.rb b/temporalio/lib/temporalio/workflow.rb
index c13da19c..8a20bcce 100644
--- a/temporalio/lib/temporalio/workflow.rb
+++ b/temporalio/lib/temporalio/workflow.rb
@@ -38,6 +38,24 @@ def self.continue_as_new_suggested
       _current.continue_as_new_suggested
     end
 
+    # Get current details for this workflow that may appear in UI/CLI. Unlike static details set at start, this value
+    # can be updated throughout the life of the workflow. This can be in Temporal markdown format and can span multiple
+    # lines. This is currently experimental.
+    #
+    # @return [String] Current details. Default is empty string.
+    def self.current_details
+      _current.current_details
+    end
+
+    # Set current details for this workflow that may appear in UI/CLI. Unlike static details set at start, this value
+    # can be updated throughout the life of the workflow. This can be in Temporal markdown format and can span multiple
+    # lines. This is currently experimental.
+    #
+    # @param details [String] Current details. Can use empty string to unset.
+    def self.current_details=(details)
+      _current.current_details = details
+    end
+
     # @return [Integer] Current number of events in history. This value is the current history event count up until the
     #   current task. Note, this value may not be up to date when accessed in a query.
     def self.current_history_length
@@ -77,6 +95,8 @@ def self.deprecate_patch(patch_id)
     # @param activity [Class<Activity::Definition>, Symbol, String] Activity definition class or activity name.
     # @param args [Array<Object>] Arguments to the activity.
     # @param task_queue [String] Task queue to run the activity on. Defaults to the current workflow's task queue.
+    # @param summary [String, nil] Single-line summary for this activity that may appear in CLI/UI. This can be in
+    #   single-line Temporal markdown format. This is currently experimental.
     # @param schedule_to_close_timeout [Float, nil] Max amount of time the activity can take from first being scheduled
     #   to being completed before it times out. This is inclusive of all retries.
     # @param schedule_to_start_timeout [Float, nil] Max amount of time the activity can take to be started from first
@@ -107,6 +127,7 @@ def self.execute_activity(
       activity,
       *args,
       task_queue: info.task_queue,
+      summary: nil,
       schedule_to_close_timeout: nil,
       schedule_to_start_timeout: nil,
       start_to_close_timeout: nil,
@@ -119,7 +140,7 @@ def self.execute_activity(
     )
       _current.execute_activity(
         activity, *args,
-        task_queue:, schedule_to_close_timeout:, schedule_to_start_timeout:, start_to_close_timeout:,
+        task_queue:, summary:, schedule_to_close_timeout:, schedule_to_start_timeout:, start_to_close_timeout:,
         heartbeat_timeout:, retry_policy:, cancellation:, cancellation_type:, activity_id:, disable_eager_execution:
       )
     end
@@ -130,6 +151,8 @@ def self.execute_child_workflow(
       *args,
       id: random.uuid,
       task_queue: info.task_queue,
+      static_summary: nil,
+      static_details: nil,
       cancellation: Workflow.cancellation,
       cancellation_type: ChildWorkflowCancellationType::WAIT_CANCELLATION_COMPLETED,
       parent_close_policy: ParentClosePolicy::TERMINATE,
@@ -144,8 +167,9 @@ def self.execute_child_workflow(
     )
       start_child_workflow(
         workflow, *args,
-        id:, task_queue:, cancellation:, cancellation_type:, parent_close_policy:, execution_timeout:, run_timeout:,
-        task_timeout:, id_reuse_policy:, retry_policy:, cron_schedule:, memo:, search_attributes:
+        id:, task_queue:, static_summary:, static_details:, cancellation:, cancellation_type:,
+        parent_close_policy:, execution_timeout:, run_timeout:, task_timeout:, id_reuse_policy:,
+        retry_policy:, cron_schedule:, memo:, search_attributes:
       ).result
     end
 
@@ -304,7 +328,7 @@ def self.signal_handlers
     #   value cannot be negative. Since Temporal timers are server-side, timer resolution may not end up as precise as
     #   system timers.
     # @param summary [String, nil] A simple string identifying this timer that may be visible in UI/CLI. While it can be
-    #   normal text, it is best to treat as a timer ID.
+    #   normal text, it is best to treat as a timer ID. This is currently experimental.
     # @param cancellation [Cancellation] Cancellation for this timer.
     # @raise [Error::CanceledError] Sleep canceled.
     def self.sleep(duration, summary: nil, cancellation: Workflow.cancellation)
@@ -317,6 +341,12 @@ def self.sleep(duration, summary: nil, cancellation: Workflow.cancellation)
     # @param args [Array<Object>] Arguments to the workflow.
     # @param id [String] Unique identifier for the workflow execution. Defaults to a new UUID from {random}.
     # @param task_queue [String] Task queue to run the workflow on. Defaults to the current workflow's task queue.
+    # @param static_summary [String, nil] Fixed single-line summary for this workflow execution that may appear in
+    #   CLI/UI. This can be in single-line Temporal markdown format. This is currently experimental.
+    # @param static_details [String, nil] Fixed details for this workflow execution that may appear in CLI/UI. This can
+    #   be in Temporal markdown format and can be multiple lines. This is a fixed value on the workflow that cannot be
+    #   updated. For details that can be updated, use {Workflow.current_details=} within the workflow. This is currently
+    #   experimental.
     # @param cancellation [Cancellation] Cancellation to apply to the child workflow. How cancellation is treated is
     #   based on `cancellation_type`. This defaults to the workflow's cancellation.
     # @param cancellation_type [ChildWorkflowCancellationType] How the child workflow will react to cancellation.
@@ -339,6 +369,8 @@ def self.start_child_workflow(
       *args,
       id: random.uuid,
       task_queue: info.task_queue,
+      static_summary: nil,
+      static_details: nil,
       cancellation: Workflow.cancellation,
       cancellation_type: ChildWorkflowCancellationType::WAIT_CANCELLATION_COMPLETED,
       parent_close_policy: ParentClosePolicy::TERMINATE,
@@ -353,8 +385,9 @@ def self.start_child_workflow(
     )
       _current.start_child_workflow(
         workflow, *args,
-        id:, task_queue:, cancellation:, cancellation_type:, parent_close_policy:, execution_timeout:, run_timeout:,
-        task_timeout:, id_reuse_policy:, retry_policy:, cron_schedule:, memo:, search_attributes:
+        id:, task_queue:, static_summary:, static_details:, cancellation:, cancellation_type:,
+        parent_close_policy:, execution_timeout:, run_timeout:, task_timeout:, id_reuse_policy:,
+        retry_policy:, cron_schedule:, memo:, search_attributes:
       )
     end
 
@@ -367,8 +400,8 @@ def self.start_child_workflow(
     #   exception.
     # @param message [String] Message to use for timeout exception. Defaults to "execution expired" like
     #   {::Timeout.timeout}.
-    # @param summary [String] Timer summer for the timer created by this timeout. This is backed by {sleep} so see that
-    #   method for details.
+    # @param summary [String] Timer summary for the timer created by this timeout. This is backed by {sleep} so see that
+    #   method for details. This is currently experimental.
     #
     # @yield Block to run with a timeout.
     # @return [Object] The result of the block.
diff --git a/temporalio/lib/temporalio/workflow/definition.rb b/temporalio/lib/temporalio/workflow/definition.rb
index ee172820..d24da3bd 100644
--- a/temporalio/lib/temporalio/workflow/definition.rb
+++ b/temporalio/lib/temporalio/workflow/definition.rb
@@ -72,7 +72,9 @@ def workflow_failure_exception_type(*types)
         # `attr_accessor`. If a writer is needed alongside this, use `attr_writer`.
         #
         # @param attr_names [Array<Symbol>] Attributes to expose.
-        def workflow_query_attr_reader(*attr_names)
+        # @param description [String, nil] Description that may appear in CLI/UI, applied to each query handler
+        #   implicitly created. This is currently experimental.
+        def workflow_query_attr_reader(*attr_names, description: nil)
           @workflow_queries ||= {}
           attr_names.each do |attr_name|
             raise 'Expected attr to be a symbol' unless attr_name.is_a?(Symbol)
@@ -84,7 +86,7 @@ def workflow_query_attr_reader(*attr_names)
             end
 
             # Just run this as if done manually
-            workflow_query
+            workflow_query(description:)
             define_method(attr_name) { instance_variable_get("@#{attr_name}") }
           end
         end
@@ -101,6 +103,8 @@ def workflow_init(value = true) # rubocop:disable Style/OptionalBooleanParameter
         # values.
         #
         # @param name [String, Symbol, nil] Override the default name.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param dynamic [Boolean] If true, make the signal dynamic. This means it receives all other signals without
         #   handlers. This cannot have a name override since it is nameless. The first parameter will be the name. Often
         #   it is useful to have the second parameter be `*args` and `raw_args` be true.
@@ -110,19 +114,22 @@ def workflow_init(value = true) # rubocop:disable Style/OptionalBooleanParameter
         #   when the workflow ends. The default warns, but this can be disabled.
         def workflow_signal(
           name: nil,
+          description: nil,
           dynamic: false,
           raw_args: false,
           unfinished_policy: HandlerUnfinishedPolicy::WARN_AND_ABANDON
         )
           raise 'Cannot provide name if dynamic is true' if name && dynamic
 
-          self.pending_handler_details = { type: :signal, name:, dynamic:, raw_args:, unfinished_policy: }
+          self.pending_handler_details = { type: :signal, name:, description:, dynamic:, raw_args:, unfinished_policy: }
         end
 
         # Mark the next method as a workflow query with a default name as the name of the method. Queries can not have
         # any side effects, meaning they should never mutate state or try to wait on anything.
         #
         # @param name [String, Symbol, nil] Override the default name.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param dynamic [Boolean] If true, make the query dynamic. This means it receives all other queries without
         #   handlers. This cannot have a name override since it is nameless. The first parameter will be the name. Often
         #   it is useful to have the second parameter be `*args` and `raw_args` be true.
@@ -130,18 +137,21 @@ def workflow_signal(
         #   {Converters::RawValue} which is a raw payload wrapper, convertible with {Workflow.payload_converter}.
         def workflow_query(
           name: nil,
+          description: nil,
           dynamic: false,
           raw_args: false
         )
           raise 'Cannot provide name if dynamic is true' if name && dynamic
 
-          self.pending_handler_details = { type: :query, name:, dynamic:, raw_args: }
+          self.pending_handler_details = { type: :query, name:, description:, dynamic:, raw_args: }
         end
 
         # Mark the next method as a workflow update with a default name as the name of the method. Updates can return
         # values. Separate validation methods can be provided via {workflow_update_validator}.
         #
         # @param name [String, Symbol, nil] Override the default name.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param dynamic [Boolean] If true, make the update dynamic. This means it receives all other updates without
         #   handlers. This cannot have a name override since it is nameless. The first parameter will be the name. Often
         #   it is useful to have the second parameter be `*args` and `raw_args` be true.
@@ -151,13 +161,14 @@ def workflow_query(
         #   when the workflow ends. The default warns, but this can be disabled.
         def workflow_update(
           name: nil,
+          description: nil,
           dynamic: false,
           raw_args: false,
           unfinished_policy: HandlerUnfinishedPolicy::WARN_AND_ABANDON
         )
           raise 'Cannot provide name if dynamic is true' if name && dynamic
 
-          self.pending_handler_details = { type: :update, name:, dynamic:, raw_args:, unfinished_policy: }
+          self.pending_handler_details = { type: :update, name:, description:, dynamic:, raw_args:, unfinished_policy: }
         end
 
         # Mark the next method as a workflow update validator to the given update method. The validator is expected to
@@ -226,6 +237,7 @@ def self.method_added(method_name)
             [Signal.new(
               name: handler[:dynamic] ? nil : (handler[:name] || method_name).to_s,
               to_invoke: method_name,
+              description: handler[:description],
               raw_args: handler[:raw_args],
               unfinished_policy: handler[:unfinished_policy]
             ), @workflow_signals, [@workflow_queries, @workflow_updates]]
@@ -233,12 +245,14 @@ def self.method_added(method_name)
             [Query.new(
               name: handler[:dynamic] ? nil : (handler[:name] || method_name).to_s,
               to_invoke: method_name,
+              description: handler[:description],
               raw_args: handler[:raw_args]
             ), @workflow_queries, [@workflow_signals, @workflow_updates]]
           when :update
             [Update.new(
               name: handler[:dynamic] ? nil : (handler[:name] || method_name).to_s,
               to_invoke: method_name,
+              description: handler[:description],
               raw_args: handler[:raw_args],
               unfinished_policy: handler[:unfinished_policy]
             ), @workflow_updates, [@workflow_signals, @workflow_queries]]
@@ -443,7 +457,7 @@ def name
       # A signal definition. This is usually built as a result of a {Definition.workflow_signal} method, but can be
       # manually created to set at runtime on {Workflow.signal_handlers}.
       class Signal
-        attr_reader :name, :to_invoke, :raw_args, :unfinished_policy
+        attr_reader :name, :to_invoke, :description, :raw_args, :unfinished_policy
 
         # @!visibility private
         def self._name_from_parameter(signal)
@@ -462,17 +476,21 @@ def self._name_from_parameter(signal)
         #
         # @param name [String, nil] Name or nil if dynamic.
         # @param to_invoke [Symbol, Proc] Method name or proc to invoke.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param raw_args [Boolean] Whether the parameters should be raw values.
         # @param unfinished_policy [HandlerUnfinishedPolicy] How the workflow reacts when this handler is still running
         #   on workflow completion.
         def initialize(
           name:,
           to_invoke:,
+          description: nil,
           raw_args: false,
           unfinished_policy: HandlerUnfinishedPolicy::WARN_AND_ABANDON
         )
           @name = name
           @to_invoke = to_invoke
+          @description = description
           @raw_args = raw_args
           @unfinished_policy = unfinished_policy
           Internal::ProtoUtils.assert_non_reserved_name(name)
@@ -482,7 +500,7 @@ def initialize(
       # A query definition. This is usually built as a result of a {Definition.workflow_query} method, but can be
       # manually created to set at runtime on {Workflow.query_handlers}.
       class Query
-        attr_reader :name, :to_invoke, :raw_args
+        attr_reader :name, :to_invoke, :description, :raw_args
 
         # @!visibility private
         def self._name_from_parameter(query)
@@ -501,14 +519,18 @@ def self._name_from_parameter(query)
         #
         # @param name [String, nil] Name or nil if dynamic.
         # @param to_invoke [Symbol, Proc] Method name or proc to invoke.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param raw_args [Boolean] Whether the parameters should be raw values.
         def initialize(
           name:,
           to_invoke:,
+          description: nil,
           raw_args: false
         )
           @name = name
           @to_invoke = to_invoke
+          @description = description
           @raw_args = raw_args
           Internal::ProtoUtils.assert_non_reserved_name(name)
         end
@@ -517,7 +539,7 @@ def initialize(
       # An update definition. This is usually built as a result of a {Definition.workflow_update} method, but can be
       # manually created to set at runtime on {Workflow.update_handlers}.
       class Update
-        attr_reader :name, :to_invoke, :raw_args, :unfinished_policy, :validator_to_invoke
+        attr_reader :name, :to_invoke, :description, :raw_args, :unfinished_policy, :validator_to_invoke
 
         # @!visibility private
         def self._name_from_parameter(update)
@@ -536,6 +558,8 @@ def self._name_from_parameter(update)
         #
         # @param name [String, nil] Name or nil if dynamic.
         # @param to_invoke [Symbol, Proc] Method name or proc to invoke.
+        # @param description [String, nil] Description for this handler that may appear in CLI/UI. This is currently
+        #   experimental.
         # @param raw_args [Boolean] Whether the parameters should be raw values.
         # @param unfinished_policy [HandlerUnfinishedPolicy] How the workflow reacts when this handler is still running
         #   on workflow completion.
@@ -543,12 +567,14 @@ def self._name_from_parameter(update)
         def initialize(
           name:,
           to_invoke:,
+          description: nil,
           raw_args: false,
           unfinished_policy: HandlerUnfinishedPolicy::WARN_AND_ABANDON,
           validator_to_invoke: nil
         )
           @name = name
           @to_invoke = to_invoke
+          @description = description
           @raw_args = raw_args
           @unfinished_policy = unfinished_policy
           @validator_to_invoke = validator_to_invoke
@@ -560,6 +586,7 @@ def _with_validator_to_invoke(validator_to_invoke)
           Update.new(
             name:,
             to_invoke:,
+            description:,
             raw_args:,
             unfinished_policy:,
             validator_to_invoke:
diff --git a/temporalio/sig/temporalio/client.rbs b/temporalio/sig/temporalio/client.rbs
index d80aae2d..89a4ba10 100644
--- a/temporalio/sig/temporalio/client.rbs
+++ b/temporalio/sig/temporalio/client.rbs
@@ -62,6 +62,8 @@ module Temporalio
       *Object? args,
       id: String,
       task_queue: String,
+      ?static_summary: String?,
+      ?static_details: String?,
       ?execution_timeout: duration?,
       ?run_timeout: duration?,
       ?task_timeout: duration?,
@@ -81,6 +83,8 @@ module Temporalio
       *Object? args,
       id: String,
       task_queue: String,
+      ?static_summary: String?,
+      ?static_details: String?,
       ?execution_timeout: duration?,
       ?run_timeout: duration?,
       ?task_timeout: duration?,
diff --git a/temporalio/sig/temporalio/client/interceptor.rbs b/temporalio/sig/temporalio/client/interceptor.rbs
index cb27f0e2..6e1d4ebd 100644
--- a/temporalio/sig/temporalio/client/interceptor.rbs
+++ b/temporalio/sig/temporalio/client/interceptor.rbs
@@ -8,6 +8,8 @@ module Temporalio
         attr_reader args: Array[Object?]
         attr_reader workflow_id: String
         attr_reader task_queue: String
+        attr_reader static_summary: String?
+        attr_reader static_details: String?
         attr_reader execution_timeout: duration?
         attr_reader run_timeout: duration?
         attr_reader task_timeout: duration?
@@ -27,6 +29,8 @@ module Temporalio
           args: Array[Object?],
           workflow_id: String,
           task_queue: String,
+          static_summary: String?,
+          static_details: String?,
           execution_timeout: duration?,
           run_timeout: duration?,
           task_timeout: duration?,
diff --git a/temporalio/sig/temporalio/client/schedule.rbs b/temporalio/sig/temporalio/client/schedule.rbs
index 43f8bfce..44014961 100644
--- a/temporalio/sig/temporalio/client/schedule.rbs
+++ b/temporalio/sig/temporalio/client/schedule.rbs
@@ -66,6 +66,8 @@ module Temporalio
           attr_reader args: Array[Object?]
           attr_reader id: String
           attr_reader task_queue: String
+          attr_reader static_summary: String?
+          attr_reader static_details: String?
           attr_reader execution_timeout: duration?
           attr_reader run_timeout: duration?
           attr_reader task_timeout: duration?
@@ -79,6 +81,8 @@ module Temporalio
             *Object? args,
             id: String,
             task_queue: String,
+            ?static_summary: String?,
+            ?static_details: String?,
             ?execution_timeout: duration?,
             ?run_timeout: duration?,
             ?task_timeout: duration?,
diff --git a/temporalio/sig/temporalio/client/with_start_workflow_operation.rbs b/temporalio/sig/temporalio/client/with_start_workflow_operation.rbs
index 997ec95c..36b97c17 100644
--- a/temporalio/sig/temporalio/client/with_start_workflow_operation.rbs
+++ b/temporalio/sig/temporalio/client/with_start_workflow_operation.rbs
@@ -6,6 +6,8 @@ module Temporalio
         attr_reader args: Array[Object?]
         attr_reader id: String
         attr_reader task_queue: String
+        attr_reader static_summary: String?
+        attr_reader static_details: String?
         attr_reader execution_timeout: duration?
         attr_reader run_timeout: duration?
         attr_reader task_timeout: duration?
@@ -23,6 +25,8 @@ module Temporalio
           args: Array[Object?],
           id: String,
           task_queue: String,
+          static_summary: String?,
+          static_details: String?,
           execution_timeout: duration?,
           run_timeout: duration?,
           task_timeout: duration?,
@@ -44,6 +48,8 @@ module Temporalio
         *Object? args,
         id: String,
         task_queue: String,
+        ?static_summary: String?,
+        ?static_details: String?,
         ?execution_timeout: duration?,
         ?run_timeout: duration?,
         ?task_timeout: duration?,
diff --git a/temporalio/sig/temporalio/client/workflow_execution.rbs b/temporalio/sig/temporalio/client/workflow_execution.rbs
index 8047a1c8..4fc83350 100644
--- a/temporalio/sig/temporalio/client/workflow_execution.rbs
+++ b/temporalio/sig/temporalio/client/workflow_execution.rbs
@@ -23,6 +23,11 @@ module Temporalio
         attr_reader raw_description: untyped
 
         def initialize: (untyped raw_description, Converters::DataConverter data_converter) -> void
+
+        def static_summary: -> String?
+        def static_details: -> String?
+
+        private def user_metadata: -> [String?, String?]
       end
     end
   end
diff --git a/temporalio/sig/temporalio/internal/proto_utils.rbs b/temporalio/sig/temporalio/internal/proto_utils.rbs
index 17d40d5f..8163528b 100644
--- a/temporalio/sig/temporalio/internal/proto_utils.rbs
+++ b/temporalio/sig/temporalio/internal/proto_utils.rbs
@@ -62,6 +62,17 @@ module Temporalio
       def self.assert_non_reserved_name: (String | Symbol | nil name) -> void
       def self.reserved_name?: (String | Symbol | nil name) -> bool
 
+      def self.to_user_metadata: (
+        String? summary,
+        String? details,
+        Converters::DataConverter | Converters::PayloadConverter converter
+      ) -> untyped
+
+      def self.from_user_metadata: (
+        untyped metadata,
+        Converters::DataConverter | Converters::PayloadConverter converter
+      ) -> [String?, String?]
+
       class LazyMemo
         def initialize: (
           untyped? raw_memo,
diff --git a/temporalio/sig/temporalio/internal/worker/workflow_instance.rbs b/temporalio/sig/temporalio/internal/worker/workflow_instance.rbs
index 19716d40..06b83ce4 100644
--- a/temporalio/sig/temporalio/internal/worker/workflow_instance.rbs
+++ b/temporalio/sig/temporalio/internal/worker/workflow_instance.rbs
@@ -34,6 +34,8 @@ module Temporalio
         attr_reader update_handlers: Hash[String?, Workflow::Definition::Update]
         attr_reader context_frozen: bool
 
+        attr_accessor current_details: String?
+
         def initialize: (Details details) -> void
 
         def activate: (untyped activation) -> untyped
@@ -90,6 +92,8 @@ module Temporalio
           ?ignore_first_param: bool
         ) -> Array[Object?]
 
+        def workflow_metadata: -> untyped
+
         def scoped_logger_info: -> Hash[Symbol, Object?]
 
         def warn_on_any_unfinished_handlers: -> void
diff --git a/temporalio/sig/temporalio/internal/worker/workflow_instance/context.rbs b/temporalio/sig/temporalio/internal/worker/workflow_instance/context.rbs
index 552fab8d..3307df42 100644
--- a/temporalio/sig/temporalio/internal/worker/workflow_instance/context.rbs
+++ b/temporalio/sig/temporalio/internal/worker/workflow_instance/context.rbs
@@ -11,6 +11,9 @@ module Temporalio
 
           def continue_as_new_suggested: -> bool
 
+          def current_details: -> String
+          def current_details=: (String? details) -> void
+
           def current_history_length: -> Integer
 
           def current_history_size: -> Integer
@@ -23,6 +26,7 @@ module Temporalio
             singleton(Activity::Definition) | Symbol | String activity,
             *Object? args,
             task_queue: String,
+            summary: String?,
             schedule_to_close_timeout: duration?,
             schedule_to_start_timeout: duration?,
             start_to_close_timeout: duration?,
@@ -86,6 +90,8 @@ module Temporalio
             *Object? args,
             id: String,
             task_queue: String,
+            static_summary: String?,
+            static_details: String?,
             cancellation: Cancellation,
             cancellation_type: Workflow::ChildWorkflowCancellationType::enum,
             parent_close_policy: Workflow::ParentClosePolicy::enum,
diff --git a/temporalio/sig/temporalio/worker/interceptor.rbs b/temporalio/sig/temporalio/worker/interceptor.rbs
index 702a0d73..731fa8f1 100644
--- a/temporalio/sig/temporalio/worker/interceptor.rbs
+++ b/temporalio/sig/temporalio/worker/interceptor.rbs
@@ -132,6 +132,7 @@ module Temporalio
           attr_reader activity: singleton(Temporalio::Activity::Definition) | Symbol | String
           attr_reader args: Array[Object?]
           attr_reader task_queue: String
+          attr_reader summary: String?
           attr_reader schedule_to_close_timeout: duration?
           attr_reader schedule_to_start_timeout: duration?
           attr_reader start_to_close_timeout: duration?
@@ -147,6 +148,7 @@ module Temporalio
             activity: singleton(Temporalio::Activity::Definition) | Symbol | String,
             args: Array[Object?],
             task_queue: String,
+            summary: String?,
             schedule_to_close_timeout: duration?,
             schedule_to_start_timeout: duration?,
             start_to_close_timeout: duration?,
@@ -247,6 +249,8 @@ module Temporalio
           attr_reader args: Array[Object?]
           attr_reader id: String
           attr_reader task_queue: String
+          attr_reader static_summary: String?
+          attr_reader static_details: String?
           attr_reader cancellation: Cancellation
           attr_reader cancellation_type: Temporalio::Workflow::ChildWorkflowCancellationType::enum
           attr_reader parent_close_policy: Temporalio::Workflow::ParentClosePolicy::enum
@@ -265,6 +269,8 @@ module Temporalio
             args: Array[Object?],
             id: String,
             task_queue: String,
+            static_summary: String?,
+            static_details: String?,
             cancellation: Cancellation,
             cancellation_type: Temporalio::Workflow::ChildWorkflowCancellationType::enum,
             parent_close_policy: Temporalio::Workflow::ParentClosePolicy::enum,
diff --git a/temporalio/sig/temporalio/workflow.rbs b/temporalio/sig/temporalio/workflow.rbs
index 2fded9bd..cbc75e24 100644
--- a/temporalio/sig/temporalio/workflow.rbs
+++ b/temporalio/sig/temporalio/workflow.rbs
@@ -6,6 +6,9 @@ module Temporalio
 
     def self.continue_as_new_suggested: -> bool
 
+    def self.current_details: -> String
+    def self.current_details=: (String? details) -> void
+
     def self.current_history_length: -> Integer
 
     def self.current_history_size: -> Integer
@@ -16,6 +19,7 @@ module Temporalio
       singleton(Activity::Definition) | Symbol | String activity,
       *Object? args,
       ?task_queue: String,
+      ?summary: String?,
       ?schedule_to_close_timeout: duration?,
       ?schedule_to_start_timeout: duration?,
       ?start_to_close_timeout: duration?,
@@ -32,6 +36,8 @@ module Temporalio
       *Object? args,
       ?id: String,
       ?task_queue: String,
+      ?static_summary: String?,
+      ?static_details: String?,
       ?cancellation: Cancellation,
       ?cancellation_type: ChildWorkflowCancellationType::enum,
       ?parent_close_policy: ParentClosePolicy::enum,
@@ -93,6 +99,8 @@ module Temporalio
       *Object? args,
       ?id: String,
       ?task_queue: String,
+      ?static_summary: String?,
+      ?static_details: String?,
       ?cancellation: Cancellation,
       ?cancellation_type: Workflow::ChildWorkflowCancellationType::enum,
       ?parent_close_policy: Workflow::ParentClosePolicy::enum,
diff --git a/temporalio/sig/temporalio/workflow/definition.rbs b/temporalio/sig/temporalio/workflow/definition.rbs
index 5fd87d15..f4928943 100644
--- a/temporalio/sig/temporalio/workflow/definition.rbs
+++ b/temporalio/sig/temporalio/workflow/definition.rbs
@@ -5,12 +5,13 @@ module Temporalio
       def self.workflow_dynamic: (?bool value) -> void
       def self.workflow_raw_args: (?bool value) -> void
       def self.workflow_failure_exception_type: (*singleton(Exception) types) -> void
-      def self.workflow_query_attr_reader: (*Symbol attr_names) -> void
+      def self.workflow_query_attr_reader: (*Symbol attr_names, ?description: String?) -> void
 
       def self.workflow_init: (?bool value) -> void
 
       def self.workflow_signal: (
         ?name: String | Symbol | nil,
+        ?description: String?,
         ?dynamic: bool,
         ?raw_args: bool,
         ?unfinished_policy: HandlerUnfinishedPolicy::enum
@@ -18,12 +19,14 @@ module Temporalio
 
       def self.workflow_query: (
         ?name: String | Symbol | nil,
+        ?description: String?,
         ?dynamic: bool,
         ?raw_args: bool
       ) -> void
 
       def self.workflow_update: (
         ?name: String | Symbol | nil,
+        ?description: String?,
         ?dynamic: bool,
         ?raw_args: bool,
         ?unfinished_policy: HandlerUnfinishedPolicy::enum
@@ -75,6 +78,7 @@ module Temporalio
       class Signal
         attr_reader name: String?
         attr_reader to_invoke: Symbol | Proc
+        attr_reader description: String?
         attr_reader raw_args: bool
         attr_reader unfinished_policy: HandlerUnfinishedPolicy::enum
 
@@ -83,6 +87,7 @@ module Temporalio
         def initialize: (
           name: String?,
           to_invoke: Symbol | Proc,
+          ?description: String?,
           ?raw_args: bool,
           ?unfinished_policy: HandlerUnfinishedPolicy::enum
         ) -> void
@@ -91,6 +96,7 @@ module Temporalio
       class Query
         attr_reader name: String?
         attr_reader to_invoke: Symbol | Proc
+        attr_reader description: String?
         attr_reader raw_args: bool
 
         def self._name_from_parameter: (Workflow::Definition::Query | String | Symbol) -> String
@@ -98,6 +104,7 @@ module Temporalio
         def initialize: (
           name: String?,
           to_invoke: Symbol | Proc,
+          ?description: String?,
           ?raw_args: bool
         ) -> void
       end
@@ -105,6 +112,7 @@ module Temporalio
       class Update
         attr_reader name: String?
         attr_reader to_invoke: Symbol | Proc
+        attr_reader description: String?
         attr_reader raw_args: bool
         attr_reader unfinished_policy: HandlerUnfinishedPolicy::enum
         attr_reader validator_to_invoke: Symbol | Proc | nil
@@ -114,6 +122,7 @@ module Temporalio
         def initialize: (
           name: String?,
           to_invoke: Symbol | Proc,
+          ?description: String?,
           ?raw_args: bool,
           ?unfinished_policy: HandlerUnfinishedPolicy::enum,
           ?validator_to_invoke: Symbol | Proc | nil
diff --git a/temporalio/test/client_schedule_test.rb b/temporalio/test/client_schedule_test.rb
index cf9de672..7a36d302 100644
--- a/temporalio/test/client_schedule_test.rb
+++ b/temporalio/test/client_schedule_test.rb
@@ -19,6 +19,8 @@ def test_basics # rubocop:disable Metrics/AbcSize
       { actions: [{ result: { value: 'some-result' } }] },
       id: "wf-#{SecureRandom.uuid}",
       task_queue:,
+      static_summary: 'my-summary',
+      static_details: 'my-details',
       execution_timeout: 1.23,
       memo: { 'memokey1' => 'memoval1' }
     )
@@ -73,6 +75,8 @@ def test_basics # rubocop:disable Metrics/AbcSize
     assert_instance_of Temporalio::Client::Schedule::Action::StartWorkflow, desc_action
     assert_equal action.workflow, desc_action.workflow
     assert_equal 'some-result', desc_action.args.first['actions'].first['result']['value'] # steep:ignore
+    assert_equal 'my-summary', desc_action.static_summary
+    assert_equal 'my-details', desc_action.static_details
     assert_equal action.execution_timeout, desc_action.execution_timeout
     assert_equal({ 'memokey1' => 'memoval1' }, desc_action.memo)
     assert_equal({ 'memokey2' => 'memoval2' }, desc.memo)
diff --git a/temporalio/test/worker_workflow_handler_test.rb b/temporalio/test/worker_workflow_handler_test.rb
index 94493f1c..595aaee3 100644
--- a/temporalio/test/worker_workflow_handler_test.rb
+++ b/temporalio/test/worker_workflow_handler_test.rb
@@ -764,6 +764,60 @@ def test_update_with_start_cancel
     end
   end
 
+  def test_update_with_start_start_fail
+    # Run worker
+    worker = Temporalio::Worker.new(
+      client: env.client,
+      task_queue: "tq-#{SecureRandom.uuid}",
+      workflows: [UpdateWithStartWorkflow]
+    )
+    worker.run do
+      id = "wf-#{SecureRandom.uuid}"
+      # Start the workflow
+      env.client.start_workflow(UpdateWithStartWorkflow, 123, id:, task_queue: worker.task_queue)
+      # Try to update-with-start on already existing, confirm call and getting handle fail
+      start_workflow_operation = Temporalio::Client::WithStartWorkflowOperation.new(
+        UpdateWithStartWorkflow, 123,
+        id:, task_queue: worker.task_queue, id_conflict_policy: Temporalio::WorkflowIDConflictPolicy::FAIL
+      )
+      assert_raises(Temporalio::Error::WorkflowAlreadyStartedError) do
+        env.client.start_update_with_start_workflow(
+          UpdateWithStartWorkflow.increment_counter, 456,
+          wait_for_stage: Temporalio::Client::WorkflowUpdateWaitStage::ACCEPTED, start_workflow_operation:
+        )
+      end
+      assert_raises(Temporalio::Error::WorkflowAlreadyStartedError) do
+        start_workflow_operation.workflow_handle
+      end
+    end
+  end
+
+  def test_update_with_start_user_metadata
+    # Run worker
+    worker = Temporalio::Worker.new(
+      client: env.client,
+      task_queue: "tq-#{SecureRandom.uuid}",
+      workflows: [UpdateWithStartWorkflow]
+    )
+    worker.run do
+      id = "wf-#{SecureRandom.uuid}"
+      start_workflow_operation = Temporalio::Client::WithStartWorkflowOperation.new(
+        UpdateWithStartWorkflow, 123,
+        id:, task_queue: worker.task_queue,
+        static_summary: 'my-summary', static_details: 'my-details',
+        id_conflict_policy: Temporalio::WorkflowIDConflictPolicy::FAIL
+      )
+      # Run and confirm metadata present
+      env.client.start_update_with_start_workflow(
+        UpdateWithStartWorkflow.increment_counter, 456,
+        wait_for_stage: Temporalio::Client::WorkflowUpdateWaitStage::ACCEPTED, start_workflow_operation:
+      )
+      desc = start_workflow_operation.workflow_handle.describe
+      assert_equal 'my-summary', desc.static_summary
+      assert_equal 'my-details', desc.static_details
+    end
+  end
+
   class SignalWithStartWorkflow < Temporalio::Workflow::Definition
     workflow_query_attr_reader :events
 
@@ -818,4 +872,28 @@ def test_signal_with_start
       assert_equal %w[signal workflow-start signal-0 signal-1 signal-2], handle.query(SignalWithStartWorkflow.events)
     end
   end
+
+  def test_signal_with_start_user_metadata
+    # Run worker
+    worker = Temporalio::Worker.new(
+      client: env.client,
+      task_queue: "tq-#{SecureRandom.uuid}",
+      workflows: [SignalWithStartWorkflow]
+    )
+    worker.run do
+      # Newly started
+      id = "wf-#{SecureRandom.uuid}"
+      start_workflow_operation = Temporalio::Client::WithStartWorkflowOperation.new(
+        SignalWithStartWorkflow, 'workflow-start',
+        id:, task_queue: worker.task_queue,
+        static_summary: 'my-summary', static_details: 'my-details'
+      )
+      handle = env.client.signal_with_start_workflow(
+        SignalWithStartWorkflow.add_event, 'signal', start_workflow_operation:
+      )
+      desc = handle.describe
+      assert_equal 'my-summary', desc.static_summary
+      assert_equal 'my-details', desc.static_details
+    end
+  end
 end
diff --git a/temporalio/test/worker_workflow_test.rb b/temporalio/test/worker_workflow_test.rb
index 9e4e5492..b3fbe553 100644
--- a/temporalio/test/worker_workflow_test.rb
+++ b/temporalio/test/worker_workflow_test.rb
@@ -1976,6 +1976,140 @@ def test_reserved_names
     end
   end
 
+  class UserMetadataWorkflow < Temporalio::Workflow::Definition
+    def execute(return_immediately)
+      return 'done' if return_immediately
+
+      # Timer, activity, and child with metadata
+      Temporalio::Workflow.sleep(0.1, summary: 'my-timer')
+
+      # Timeout over wait condition
+      begin
+        Temporalio::Workflow.timeout(0.1, summary: 'my-timeout-timer') { Temporalio::Workflow.wait_condition { false } }
+        raise 'Did not timeout'
+      rescue Timeout::Error
+        # Ignore
+      end
+
+      # Activity
+      Temporalio::Workflow.execute_activity(
+        UserMetadataActivity,
+        start_to_close_timeout: 30,
+        summary: 'my-activity'
+      )
+
+      # Child
+      Temporalio::Workflow.execute_child_workflow(
+        UserMetadataWorkflow, true,
+        static_summary: 'my-child', static_details: 'my-child-details'
+      )
+    end
+  end
+
+  class UserMetadataActivity < Temporalio::Activity::Definition
+    def execute
+      'done'
+    end
+  end
+
+  def test_user_metadata
+    execute_workflow(UserMetadataWorkflow, false, activities: [UserMetadataActivity]) do |handle|
+      assert_equal 'done', handle.result
+      # Check history
+      events = handle.fetch_history.events
+      timers = events.select(&:timer_started_event_attributes)
+      assert_equal '"my-timer"', timers.first.user_metadata.summary.data
+      assert_equal '"my-timeout-timer"', timers.last.user_metadata.summary.data
+      assert_equal '"my-activity"', events.find(&:activity_task_scheduled_event_attributes).user_metadata.summary.data
+      child = events.find(&:start_child_workflow_execution_initiated_event_attributes)
+      assert_equal '"my-child"', child.user_metadata.summary.data
+      assert_equal '"my-child-details"', child.user_metadata.details.data
+
+      # Describe the child and confirm metadata
+      child_desc = env.client.workflow_handle(
+        child.start_child_workflow_execution_initiated_event_attributes.workflow_id
+      ).describe
+      assert_equal 'my-child', child_desc.static_summary
+      assert_equal 'my-child-details', child_desc.static_details
+    end
+  end
+
+  class WorkflowMetadataWorkflow < Temporalio::Workflow::Definition
+    workflow_query_attr_reader :continue, description: 'continue description'
+
+    def execute
+      Temporalio::Workflow.current_details = 'initial current details'
+      Temporalio::Workflow.signal_handlers['some manual signal'] = Temporalio::Workflow::Definition::Signal.new(
+        name: 'some manual signal',
+        to_invoke: proc {},
+        description: 'some manual signal description'
+      )
+      Temporalio::Workflow.wait_condition { @continue }
+      Temporalio::Workflow.current_details = 'final current details'
+    end
+
+    workflow_signal
+    def some_signal; end
+
+    workflow_signal name: 'some signal', description: 'some signal description'
+    def some_other_signal; end
+
+    workflow_query description: 'some query description', dynamic: true
+    def some_query(name, *args); end
+
+    workflow_update description: 'some update description'
+    def some_update
+      @continue = true
+    end
+
+    workflow_update name: 'some update'
+    def some_other_update; end
+  end
+
+  def test_workflow_metadata
+    execute_workflow(WorkflowMetadataWorkflow) do |handle|
+      # Check workflow metadata
+      assert_equal Temporalio::Api::Sdk::V1::WorkflowMetadata.new(
+        definition: Temporalio::Api::Sdk::V1::WorkflowDefinition.new(
+          type: 'WorkflowMetadataWorkflow',
+          query_definitions: [
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'continue', description: 'continue description'
+            ),
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              description: 'some query description'
+            )
+          ],
+          signal_definitions: [
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'some_signal'
+            ),
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'some signal', description: 'some signal description'
+            ),
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'some manual signal', description: 'some manual signal description'
+            )
+          ],
+          update_definitions: [
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'some_update', description: 'some update description'
+            ),
+            Temporalio::Api::Sdk::V1::WorkflowInteractionDefinition.new(
+              name: 'some update'
+            )
+          ]
+        ),
+        current_details: 'initial current details'
+      ), handle.query(:__temporal_workflow_metadata)
+
+      # Complete and check final details
+      handle.execute_update(WorkflowMetadataWorkflow.some_update)
+      handle.result
+      assert_equal 'final current details', handle.query(:__temporal_workflow_metadata).current_details
+    end
+  end
+
   # TODO(cretz): To test
   # * Common
   #   * Eager workflow start