Observability
~2 min read
Concept & How It Works
Why Does It Exist?
Agents are non-deterministic distributed systems. Without observability you're blind to which step failed, why latency spiked, or which prompt version caused regressions.
Real-World Analogy
Agent observability is an airplane cockpit — instruments for altitude (latency), fuel (tokens/cost), and warning lights (errors) so you don't fly blind.
Visual Workflows
What is Observability?
Example
Scenario
Dashboard shows Billing Agent p95 latency doubled after a deploy — trace drill-down reveals new retriever returning 20 chunks instead of 5.
Solution
In Agent Evaluation & Observability, apply Observability to this scenario: Dashboard shows Billing Agent p95 latency doubled after a deploy — trace drill-down reveals new retriever returning 20 chunks instead of 5. Identify the inputs, run the technique, validate the output, and note one thing you would monitor in production.
Practice Task
Do this before moving to the next module — reading alone is not enough.
Open the Code Walkthrough below and run it locally. Change one parameter related to Observability (e.g. model, temperature, top_k, or tool name), observe the difference in output, and write 2–3 sentences explaining what changed.
Code Walkthrough
Highlighted lines show where Observability happens in the code.
1from opentelemetry import trace # import dependencies2tracer = trace.get_tracer("support-agent")3
4with tracer.start_as_current_span("tool.lookup_invoice") as span:5 span.set_attribute("invoice_id", inv_id)6 result = lookup_invoice(inv_id)Commands to Remember
Commands to Remember
pip install langsmith # trace and evaluate LLM runspip install arize-phoenix # open-source LLM observabilitypip install opentelemetry-api opentelemetry-sdk # distributed tracing
Common Mistakes
- Treating Observability as a black box without evaluation
- Ignoring cost and latency in production
- Skipping error handling for observability
Cheat Sheet
Quick recap — the most important points from this module.
Cheat Sheet
quick ref- •Observability
- •Traces
- •Spans
- •SLIs