Class: Brute::Middleware::OTel::Span

Inherits:
Base
  • Object
show all
Defined in:
lib/brute/middleware/otel/span.rb

Overview

Outermost OTel middleware. Creates a span per LLM pipeline call and passes it through env for inner OTel middlewares to decorate with events and attributes.

When opentelemetry-sdk is not loaded, this is a pure pass-through.

Pipeline position: outermost (wraps everything including retries).

use Brute::Middleware::OTel::Span
use Brute::Middleware::OTel::ToolResults
use Brute::Middleware::OTel::ToolCalls
use Brute::Middleware::OTel::TokenUsage
# ... existing middleware ...
run Brute::Middleware::LLMCall.new

Instance Method Summary collapse

Methods inherited from Base

#initialize

Constructor Details

This class inherits a constructor from Brute::Middleware::Base

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/brute/middleware/otel/span.rb', line 27

def call(env)
  return @app.call(env) unless defined?(::OpenTelemetry::SDK)

  provider_name = provider_type(env[:provider])
  model = begin; env[:context].model; rescue; nil; end
  span_name = model ? "llm.call #{model}" : "llm.call"

  attributes = {
    "brute.provider" => provider_name,
    "brute.streaming" => !!env[:streaming],
    "brute.context_messages" => env[:context].messages.to_a.size,
  }
  attributes["brute.model"] = model.to_s if model
  attributes["brute.session_id"] = env[:metadata][:session_id].to_s if env.dig(:metadata, :session_id)

  tracer.in_span(span_name, attributes: attributes, kind: :internal) do |span|
    env[:span] = span
    response = @app.call(env)

    # Record response model if it differs from request model
    resp_model = begin; response.model; rescue; nil; end
    span.set_attribute("brute.response_model", resp_model.to_s) if resp_model && resp_model != model

    response
  rescue ::StandardError => e
    span.record_exception(e)
    span.status = ::OpenTelemetry::Trace::Status.error(e.message)
    raise
  ensure
    env.delete(:span)
  end
end