Module: PlatformSdk::Observability::Langfuse::OpenAIAdapter

Defined in:
lib/platform_sdk/observability/langfuse/openai_adapter.rb

Overview

Fires ‘llm_call.platform_sdk` ActiveSupport::Notifications events with a payload extracted from a `ruby-openai` chat call. Apps that hit OpenAI’s chat completions API directly (rather than via RubyLLM) call ‘with_observability` to get cost, tokens, model, input, and output captured in Langfuse:

PlatformSdk::Observability::Langfuse::OpenAIAdapter.with_observability(
  parameters: { model: 'gpt-4o', messages: [...], ... },
  context: 'amend_json'
) do
  OpenAI::Client.new.chat(parameters: parameters)
end

The block runs the actual LLM call and its return value is forwarded back to the caller. On success a generation observation is recorded with model/usage from the response. On raise a failure observation is recorded and the exception is re-raised unchanged.

No hard dependency on the ‘ruby-openai` gem — this adapter only touches the plain-Hash response shape OpenAI’s API returns.

Class Method Summary collapse

Class Method Details

.fire(parameters:, response:, context:, error: nil) ⇒ Object

Fire a single ‘llm_call.platform_sdk` notification. Useful when the caller has already invoked OpenAI and just wants to record the observation after the fact.



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# File 'lib/platform_sdk/observability/langfuse/openai_adapter.rb', line 46

def fire(parameters:, response:, context:, error: nil)
  payload = build_payload(parameters:, response:, context:, error:)
  return unless payload

  ActiveSupport::Notifications.instrument(LLM_CALL_EVENT, payload)
rescue StandardError => e
  OpenTelemetry.handle_error(
    message: "OpenAIAdapter.fire failed: #{e.class}: #{e.message[0, 200]}"
  )
  nil
end

.with_observability(parameters:, context:) ⇒ Object

Wrap an ‘OpenAI::Client#chat` call. Forwards the block’s return value. On success: fires success notification with model/input/ output/usage extracted from ‘parameters` and the returned response. On raise: fires failure notification with `error:` set, re-raises.



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# File 'lib/platform_sdk/observability/langfuse/openai_adapter.rb', line 34

def with_observability(parameters:, context:)
  response = yield
  fire(parameters:, response:, context:)
  response
rescue StandardError => e
  fire(parameters:, response: nil, context:, error: e)
  raise
end