ask-opentelemetry

OpenTelemetry tracing for the ask-rb ecosystem. Subscribes to ask-instrumentation events and creates OpenTelemetry spans for chat completions, tool calls, embeddings, and image generation. Backend-agnostic: the exporter is configured with the standard OpenTelemetry SDK, so spans go to any OpenTelemetry-compatible backend (Langfuse, Datadog, Honeycomb, Jaeger, Arize Phoenix, and more).

Installation

gem "ask-opentelemetry"
gem "ask-instrumentation"

Quick Start

require "ask/open_telemetry"

Ask::OpenTelemetry.install

That's it. Every Ask::Instrumentation event is now wrapped in a span. The call is idempotent; subsequent calls are no-ops.

In a Rails app, the Railtie calls Ask::OpenTelemetry.install automatically: no manual setup required.

Spans Created

Event	Span
chat.ask, chat.stream.ask	llm.chat
tool.ask	llm.tool
embedding.ask	llm.embedding
image.ask	llm.image

Span attributes use the llm.* namespace: llm.provider, llm.model, llm.input_tokens, llm.output_tokens, llm.duration_ms, llm.tool, llm.tool_args, and llm.image.size when present. Any context set via Ask::Instrumentation.with_metadata is forwarded as llm.metadata.* attributes.

Configuration

Ask::OpenTelemetry.install is the entire public API; there is no exporter configuration on the gem itself. Configure the exporter once with the standard OpenTelemetry SDK before calling install:

require "opentelemetry-sdk"
require "opentelemetry-exporter-otlp"

OpenTelemetry::SDK.configure do |c|
  c.service_name = "my-app"
  c.add_span_processor(
    OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor.new(
      OpenTelemetry::Exporter::OTLP::Exporter.new(endpoint: "https://otlp.example.com")
    )
  )
end

Ask::OpenTelemetry.install

Full documentation

The full ask-rb documentation lives at https://ask-rb.github.io/ask-docs. https://ask-rb.github.io/ask-docs/production/opentelemetry covers ask-opentelemetry in depth, including per-backend setup examples. API reference: https://ask-rb.github.io/ask-docs/reference/api.

Development

bundle install bundle exec rake test

License

MIT