Documentation Index
Fetch the complete documentation index at: https://handbook.fiddler.ai/llms.txt
Use this file to discover all available pages before exploring further.
What You’ll Learn
This interactive notebook demonstrates advanced monitoring patterns for production LangGraph applications through a realistic travel planning system with multiple specialized agents.
Key Topics Covered:
- Multi-agent workflow monitoring and orchestration
- Custom instrumentation with decorators and span wrappers
- Combining auto-instrumentation with fine-grained manual spans
- Conversation tracking across complex interactions
- Production configuration for high-volume scenarios
- Advanced error handling and recovery patterns
- Business intelligence integration and analytics
Interactive Tutorial
The notebook walks through building a comprehensive travel planning application featuring hotel search, weather analysis, itinerary planning, and supervisor agents working together.
Open the Advanced Observability Notebook in Google Colab →
Or download the notebook directly from GitHub →
Custom Instrumentation Tutorial
For hands-on examples of decorator-based and manual instrumentation, including @trace(), span wrappers, and async support:
Open the Custom Instrumentation Notebook in Google Colab →
Or download the notebook directly from GitHub →
Custom Instrumentation Patterns
The SDK supports three instrumentation approaches. You can use them individually or combine them in the same application. For complete API reference, see the Instrumentation Methods section in the integration guide.
Combining Auto-Instrumentation with Decorators
Use LangGraphInstrumentor for automatic LangGraph/LangChain tracing, then add @trace() decorators to capture custom business logic that runs outside the framework:
from fiddler_langgraph import FiddlerClient, LangGraphInstrumentor, trace, get_current_span
client = FiddlerClient(
application_id="your-app-id",
api_key="your-api-key",
url="https://your-instance.fiddler.ai"
)
# Auto-instrument LangGraph nodes
instrumentor = LangGraphInstrumentor(client)
instrumentor.instrument()
# Add custom tracing to business logic outside LangGraph
@trace(name="validate_input", as_type="chain")
def validate_user_input(user_message: str) -> dict:
span = get_current_span(as_type="chain")
if span:
span.set_input(user_message)
result = {"valid": True, "sanitized": user_message.strip()}
if span:
span.set_output(result)
return result
# Both auto-instrumented LangGraph spans and custom spans
# appear together in Fiddler's trace view
validated = validate_user_input(user_message)
result = agent.invoke({"messages": [{"role": "user", "content": validated["sanitized"]}]})
Multi-Agent Decorator Patterns
When building multi-agent systems, @trace() decorators automatically establish parent-child span relationships through nested function calls:
import asyncio
from fiddler_langgraph import trace, get_current_span
@trace(name="supervisor", as_type="chain")
async def supervisor_agent(state: dict) -> dict:
"""Top-level orchestrator — creates parent span."""
span = get_current_span(as_type="chain")
if span:
span.set_attribute("agent_count", len(state.get("tasks", [])))
# Child spans nest automatically under the supervisor span
results = await asyncio.gather(
research_agent(state),
analysis_agent(state),
)
if span:
span.set_output({"completed": len(results)})
return {"results": results}
@trace(name="research_agent", as_type="chain")
async def research_agent(state: dict) -> dict:
"""Child span nested under supervisor."""
span = get_current_span(as_type="chain")
if span:
span.set_attribute("data_sources", 3)
# ... research logic ...
return {"findings": "..."}
@trace(name="analysis_agent", as_type="chain")
async def analysis_agent(state: dict) -> dict:
"""Child span nested under supervisor."""
span = get_current_span(as_type="chain")
if span:
span.set_attribute("analysis_type", "comparative")
# ... analysis logic ...
return {"analysis": "..."}
Using Span Wrappers for Typed Attributes
Span wrapper classes provide typed helper methods for setting semantic attributes on LLM calls, tool invocations, and chain operations. Use them with start_as_current_span() for fine-grained control:
from fiddler_langgraph import FiddlerClient
client = FiddlerClient(
application_id="your-app-id",
api_key="your-api-key",
url="https://your-instance.fiddler.ai"
)
# as_type="generation" returns a FiddlerGeneration wrapper with LLM-specific helper methods
with client.start_as_current_span("llm_call", as_type="generation") as gen:
gen.set_model("gpt-4o")
gen.set_system_prompt("You are a travel planning assistant.")
gen.set_user_prompt(user_input)
response = call_llm(user_input)
gen.set_completion(response.content)
gen.set_usage(response.usage.prompt_tokens, response.usage.completion_tokens)
# as_type="tool" returns a FiddlerTool wrapper with tool-specific helper methods
with client.start_as_current_span("search_hotels", as_type="tool") as tool:
tool.set_tool_name("hotel_search")
tool.set_tool_input({"city": "Paris", "dates": "2026-03-01"})
results = search_hotels("Paris", "2026-03-01")
tool.set_tool_output(results)
For the complete list of helper methods on each span wrapper class, see the Span Types and Helper Methods reference.
Production Configuration Best Practices
Before deploying LangGraph applications to production, configure the SDK for your specific workload characteristics.
High-Volume Applications
Optimize for applications processing thousands of traces per minute:
import os
from opentelemetry.sdk.trace import SpanLimits, sampling
from opentelemetry.exporter.otlp.proto.http.trace_exporter import Compression
from fiddler_langgraph import FiddlerClient
# Configure batch processing BEFORE initializing FiddlerClient
os.environ['OTEL_BSP_MAX_QUEUE_SIZE'] = '500' # Increased from default 100
os.environ['OTEL_BSP_SCHEDULE_DELAY_MILLIS'] = '500' # Faster export than default 1000ms
os.environ['OTEL_BSP_MAX_EXPORT_BATCH_SIZE'] = '50' # Larger batches than default 10
os.environ['OTEL_BSP_EXPORT_TIMEOUT'] = '10000' # Longer timeout than default 5000ms
# Increase span limits to capture more data
production_limits = SpanLimits(
max_events=128, # Default: 32
max_links=64, # Default: 32
max_span_attributes=128, # Default: 32
max_event_attributes=64, # Default: 32
max_link_attributes=32, # Default: 32
max_span_attribute_length=8192, # Default: 2048
)
# Sample 5-10% of traces to manage data volume
production_sampler = sampling.TraceIdRatioBased(0.05)
client = FiddlerClient(
application_id=os.getenv("FIDDLER_APPLICATION_ID"),
api_key=os.getenv("FIDDLER_API_KEY"),
url=os.getenv("FIDDLER_URL"),
span_limits=production_limits,
sampler=production_sampler,
compression=Compression.Gzip,
)
Low-Latency Requirements
Optimize for applications requiring sub-second trace export:
import os
from opentelemetry.exporter.otlp.proto.http.trace_exporter import Compression
from fiddler_langgraph import FiddlerClient
# Reduce batch delay for faster exports
os.environ['OTEL_BSP_SCHEDULE_DELAY_MILLIS'] = '100' # Export every 100ms
os.environ['OTEL_BSP_MAX_EXPORT_BATCH_SIZE'] = '5' # Smaller batches
client = FiddlerClient(
application_id=os.getenv("FIDDLER_APPLICATION_ID"),
api_key=os.getenv("FIDDLER_API_KEY"),
url=os.getenv("FIDDLER_URL"),
compression=Compression.Gzip, # Still use compression
)
Memory-Constrained Environments
Configure conservative limits for edge deployments or containerized environments:
import os
from opentelemetry.sdk.trace import SpanLimits, sampling
from opentelemetry.exporter.otlp.proto.http.trace_exporter import Compression
from fiddler_langgraph import FiddlerClient
memory_constrained_limits = SpanLimits(
max_events=16, # Minimal event capture
max_links=16, # Minimal linking
max_span_attributes=32, # Reduced attributes
max_event_attributes=16, # Reduced event attributes
max_link_attributes=16, # Reduced link attributes
max_span_attribute_length=1024, # Shorter attribute values
)
os.environ['OTEL_BSP_MAX_QUEUE_SIZE'] = '50' # Smaller queue
os.environ['OTEL_BSP_MAX_EXPORT_BATCH_SIZE'] = '5' # Smaller batches
client = FiddlerClient(
application_id=os.getenv("FIDDLER_APPLICATION_ID"),
api_key=os.getenv("FIDDLER_API_KEY"),
url=os.getenv("FIDDLER_URL"),
span_limits=memory_constrained_limits,
sampler=sampling.TraceIdRatioBased(0.1), # Sample 10%
compression=Compression.Gzip,
)
Development vs Production Configurations
Development Configuration:
import os
from fiddler_langgraph import FiddlerClient
# Capture everything with verbose debugging
# console_tracer=True prints spans to stdout AND continues to export to Fiddler (additive)
dev_client = FiddlerClient(
application_id=os.getenv("FIDDLER_APPLICATION_ID"),
api_key=os.getenv("FIDDLER_API_KEY"),
url=os.getenv("FIDDLER_URL"),
console_tracer=True, # Also prints spans to console; does NOT disable OTLP export
sampler=None, # Capture 100% of traces
)
Production Configuration:
import os
from opentelemetry.sdk.trace import SpanLimits, sampling
from opentelemetry.exporter.otlp.proto.http.trace_exporter import Compression
from fiddler_langgraph import FiddlerClient
# Define production limits (see High-Volume Applications above for full example)
production_limits = SpanLimits(
max_events=128, max_span_attributes=128, max_span_attribute_length=8192
)
# Optimized for performance and cost
prod_client = FiddlerClient(
application_id=os.getenv("FIDDLER_APPLICATION_ID"),
api_key=os.getenv("FIDDLER_API_KEY"),
url=os.getenv("FIDDLER_URL"),
sampler=sampling.TraceIdRatioBased(0.05), # Sample 5%
compression=Compression.Gzip, # Reduce bandwidth
span_limits=production_limits, # Controlled limits
)
Best Practices for Context and Conversation IDs
Structure your identifiers for maximum analytical value:
from fiddler_langgraph import set_llm_context, set_conversation_id
import uuid
# Set meaningful, searchable context labels
set_llm_context(model, 'Customer Support - Tier 1 - Billing Inquiries')
set_llm_context(model, 'Content Generation - Marketing Copy - Blog Posts')
set_llm_context(model, 'Data Analysis - Financial Reports - Q4 2025')
# Use structured conversation IDs with metadata
user_id = 'user-12345'
session_type = 'support'
timestamp = '2026-06-15'
conversation_id = f'{user_id}_{session_type}_{timestamp}_{uuid.uuid4()}'
set_conversation_id(conversation_id)
# Example: user-12345_support_2026-06-15_550e8400-e29b-41d4-a716-446655440000
Prerequisites
- Fiddler account with API credentials
- OpenAI API key for example interactions
- Basic familiarity with LangGraph concepts
Time Required
- Complete tutorial: 45-60 minutes
- Quick overview: 15-20 minutes
Telemetry Data Reference
Understanding the data captured by the Fiddler LangGraph SDK.
Span Attributes
The SDK automatically captures these OpenTelemetry attributes:
| Attribute | Type | Description |
|---|
gen_ai.agent.name | str | Name of the AI agent (auto-extracted from LangGraph, configurable for LangChain) |
gen_ai.agent.id | str | Unique identifier (format: trace_id:agent_name) |
gen_ai.conversation.id | str | Session identifier set via set_conversation_id() |
fiddler.span.type | str | Span classification: chain, tool, llm, or agent |
gen_ai.llm.input.system | str | System prompt content |
gen_ai.llm.input.user | str | User input/prompt |
gen_ai.llm.output | str | Model response text |
gen_ai.llm.context | str | Custom context set via set_llm_context() |
gen_ai.request.model | str | Model identifier (e.g., “gpt-4o-mini”) |
gen_ai.llm.token_count | int | Token usage metrics |
gen_ai.tool.name | str | Tool function name |
gen_ai.tool.input | str | Tool input parameters (JSON) |
gen_ai.tool.output | str | Tool execution results (JSON) |
gen_ai.tool.definitions | str | Tool definitions available to the LLM (JSON array of OpenAI-format tool schemas) |
gen_ai.input.messages | str | Complete message history provided as input to the LLM (JSON array) |
gen_ai.output.messages | str | Output messages generated by the LLM, including tool calls (JSON array) |
duration_ms | float | Span duration in milliseconds |
fiddler.error.message | str | Error message (if span failed) |
fiddler.error.type | str | Error type classification |
Setting Attributes with Span Wrappers
When using manual instrumentation, span wrapper classes provide typed helper methods that set these attributes automatically. For example, FiddlerGeneration.set_model("gpt-4o") sets gen_ai.request.model, and FiddlerTool.set_tool_name("search") sets gen_ai.tool.name.
| Span Wrapper | Key Methods | Attributes Set |
|---|
FiddlerGeneration | set_model(), set_system_prompt(), set_user_prompt(), set_completion(), set_usage(), set_messages(), set_output_messages(), set_tool_definitions() | gen_ai.request.model, gen_ai.llm.input.*, gen_ai.llm.output, gen_ai.usage.*, gen_ai.input.messages, gen_ai.output.messages, gen_ai.tool.definitions |
FiddlerTool | set_tool_name(), set_tool_input(), set_tool_output(), set_tool_definitions() | gen_ai.tool.name, gen_ai.tool.input, gen_ai.tool.output, gen_ai.tool.definitions |
FiddlerChain | set_input(), set_output() | Input/output data attributes |
FiddlerSpan | set_attribute(), set_agent_name(), set_conversation_id() | Any custom or standard attribute |
For the complete method reference, see Span Types and Helper Methods.
Querying and Filtering in Fiddler
Use these attributes in the Fiddler UI to:
- Filter by agent:
gen_ai.agent.name = "hotel_search_agent"
- Find conversations:
gen_ai.conversation.id = "user-123_support_2026-06-15..."
- Analyze by model:
gen_ai.request.model = "gpt-4o"
- Track errors:
fiddler.error.type EXISTS
Who Should Use This
- AI engineers building production LangGraph applications
- DevOps teams monitoring agentic systems
- Technical leaders evaluating observability strategies
Limitations and Considerations
Current Limitations
- Framework Support: LangGraph is fully supported with automatic agent name extraction
- LangChain applications require manual agent name configuration
- Non-LangGraph Python code can use
@trace() decorators or manual context managers for custom instrumentation (see Instrumentation Methods)
- Protocol Support: Currently uses HTTP-based OTLP
- gRPC support planned for future releases
- Attribute Limits: Default OpenTelemetry limits apply
- Configurable via
span_limits parameter
- Very large attribute values may be truncated
Overhead: Typical performance impact is < 5% with default settings
- Use sampling to reduce overhead in high-volume scenarios
- Adjust batch processing delays based on latency requirements
Memory: Span queue size affects the memory footprint
- Default queue (100 spans) uses ~1-2MB
- Increase
OTEL_BSP_MAX_QUEUE_SIZE for high throughput
- Decrease for memory-constrained environments
Network: Compression significantly reduces bandwidth usage
- Gzip compression: ~70-80% reduction
- Use
Compression.NoCompression only for debugging
Production Deployment Checklist
Before deploying to production:
When to Tune Each Setting
| Scenario | Configuration |
|---|
| High-volume production | Increase queue size, batch size, sampling rate |
| Low-latency requirements | Decrease schedule delay, smaller batches |
| Memory constraints | Decrease span limits, queue size, batch size |
| Development/debugging | Disable sampling, enable console tracer |
| Cost optimization | Increase sampling (lower %), enable compression |
Next Steps
After completing the tutorial: