Class: LLM::Tracer

Inherits:
Object
  • Object
show all
Defined in:
lib/llm/tracer.rb

Overview

The LLM::Tracer is the superclass of all LLM tracers. It can be helpful for implementing instrumentation and hooking into the lifecycle of an LLM request. See LLM::Tracer::Telemetry, and LLM::Tracer::Logger for example tracer implementations.

Direct Known Subclasses

Logger, Null, Telemetry

Defined Under Namespace

Classes: Logger, Null, Telemetry

Instance Method Summary collapse

Constructor Details

#initialize(provider, options = {}) ⇒ Tracer

Returns a new instance of Tracer.

Parameters:

  • provider (LLM::Provider) —

    A provider

  • options (Hash) (defaults to: {}) —

    A hash of options



21
22
23
24
 
# File 'lib/llm/tracer.rb', line 21

def initialize(provider, options = {})
  @provider = provider
  @options = {}
end

Instance Method Details

#flush! ⇒ nil

Note:

This method is only implemented by the Telemetry tracer. It is a noop for other tracers.

Flush the tracer

Returns:

  • (nil) 


135
136
137
 
# File 'lib/llm/tracer.rb', line 135

def flush!
  nil
end

#inspect ⇒ String

Returns:

  • (String) 


119
120
121
 
# File 'lib/llm/tracer.rb', line 119

def inspect
  "#<#{self.class.name}:0x#{object_id.to_s(16)} @provider=#{@provider.class} @tracer=#{@tracer.inspect}>"
end

#on_request_error(ex:, span:)

This method returns an undefined value.

Called when an LLM provider request fails.

Parameters:

Raises:

  • (NotImplementedError) 


51
52
53
 
# File 'lib/llm/tracer.rb', line 51

def on_request_error(ex:, span:)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#on_request_finish(operation:, res:, model: nil, span: nil)

This method returns an undefined value.

Called after an LLM provider request succeeds.

Parameters:

  • operation (String)
  • model (String) (defaults to: nil)
  • res (LLM::Response)
  • span (Object, nil) (defaults to: nil)

Raises:

  • (NotImplementedError) 


42
43
44
 
# File 'lib/llm/tracer.rb', line 42

def on_request_finish(operation:, res:, model: nil, span: nil)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#on_request_start(operation:, model: nil)

This method returns an undefined value.

Called before an LLM provider request is executed.

Parameters:

  • operation (String)
  • model (String) (defaults to: nil)

Raises:

  • (NotImplementedError) 


31
32
33
 
# File 'lib/llm/tracer.rb', line 31

def on_request_start(operation:, model: nil)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#on_tool_error(ex:, span:)

This method returns an undefined value.

Called when a local tool/function raises.

Parameters:

  • ex (Exception) —

    The raised error.

  • span (Object, nil) —

    The span/context object returned by #on_tool_start.

Raises:

  • (NotImplementedError) 


88
89
90
 
# File 'lib/llm/tracer.rb', line 88

def on_tool_error(ex:, span:)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#on_tool_finish(result:, span:)

This method returns an undefined value.

Called after a local tool/function succeeds.

Parameters:

Raises:

  • (NotImplementedError) 


77
78
79
 
# File 'lib/llm/tracer.rb', line 77

def on_tool_finish(result:, span:)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#on_tool_start(id:, name:, arguments:, model:)

This method returns an undefined value.

Called before a local tool/function executes.

Parameters:

  • id (String) —

    The tool call ID assigned by the model/provider

  • name (String) —

    The tool (function) name.

  • arguments (Hash) —

    The parsed tool arguments.

  • model (String) —

    The model name

Raises:

  • (NotImplementedError) 


66
67
68
 
# File 'lib/llm/tracer.rb', line 66

def on_tool_start(id:, name:, arguments:, model:)
  raise NotImplementedError, "#{self.class} does not implement '#{__method__}'"
end

#spans ⇒ Array

Returns:

  • (Array) 


125
126
127
 
# File 'lib/llm/tracer.rb', line 125

def spans
  []
end

#start_trace(trace_group_id: nil, name: "llm", attributes: {}) ⇒ self

Opens a trace group so subsequent LLM spans share the same OpenTelemetry trace_id (and appear as one trace in backends like Langfuse). When +trace_group_id+ is a string, it is used to derive the trace_id.

Parameters:

  • trace_group_id (String, nil) (defaults to: nil) —

    Optional. When present, converted to a 16-byte trace_id so all spans created until #stop_trace are grouped in one trace.

  • name (String) (defaults to: "llm") —

    Name for the root span (e.g. "chatbot.turn").

  • attributes (Hash) (defaults to: {}) —

    OpenTelemetry attributes to set on the root span.

Returns:

  • (self) 


105
106
107
 
# File 'lib/llm/tracer.rb', line 105

def start_trace(trace_group_id: nil, name: "llm", attributes: {})
  self
end

#stop_trace ⇒ self

Finishes the trace group started by #start_trace. Safe to call even if no trace is active.

Returns:

  • (self) 


113
114
115
 
# File 'lib/llm/tracer.rb', line 113

def stop_trace
  self
end