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Documentation Index

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PyPI

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Deprecation notices

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Re-exported fiddler-otel symbols

Importing core fiddler-otel symbols directly from fiddler_langgraph is deprecated and will be removed in a future major release. This affects the following imports: 
# Deprecated — will be removed in a future release
from fiddler_langgraph import FiddlerClient
from fiddler_langgraph import FiddlerSpan, FiddlerGeneration, FiddlerChain, FiddlerTool
from fiddler_langgraph import trace, get_current_span, get_client, set_conversation_id
Recommended migration: Import these symbols from fiddler_otel directly: 
# Correct — import from fiddler_otel
from fiddler_otel import FiddlerClient
from fiddler_otel import FiddlerSpan, FiddlerGeneration, FiddlerChain, FiddlerTool
from fiddler_otel import trace, get_current_span, get_client, set_conversation_id
LangGraphInstrumentor, add_session_attributes, add_span_attributes, and set_llm_context remain in fiddler_langgraph and are not affected.

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1.4

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1.4.2
Fiddler LangGraph SDK
April 2026
Breaking change released as a patch version. If you are upgrading from 1.4.1 or earlier, see the migration steps below.
  • Breaking Changes
    • Module restructure — fiddler_langgraph.tracing removed and instrumentor class renamed: The internal tracing sub-package has been removed and the instrumentor class has been renamed from FiddlerLangChainInstrumentor to LangGraphInstrumentor. All existing code using the old import path must be updated. Old import (1.4.1 and earlier): 
      from fiddler_langgraph.tracing.instrumentation import FiddlerLangChainInstrumentor

instrumentor = FiddlerLangChainInstrumentor(client=client)
instrumentor.instrument()
      New import (1.4.2+): 
      from fiddler_langgraph import LangGraphInstrumentor

instrumentor = LangGraphInstrumentor(client=client)
instrumentor.instrument()
      Migration: Update the import path and rename FiddlerLangChainInstrumentor to LangGraphInstrumentor. The constructor signature and all methods (instrument(), uninstrument()) are identical — no other code changes required. Impact: Upgrading to 1.4.2 without updating the import raises ModuleNotFoundError: No module named 'fiddler_langgraph.tracing'. If you cannot upgrade immediately, pin to fiddler-langgraph==1.4.1.
    • Other functions relocated from fiddler_langgraph.tracing.instrumentation: The following utility functions were also in the removed tracing sub-package. They are now importable directly from fiddler_langgraph:
      FunctionOld import (1.4.1 and earlier)New import (1.4.2+)
      add_session_attributesfrom fiddler_langgraph.tracing.instrumentation import add_session_attributesfrom fiddler_langgraph import add_session_attributes
      add_span_attributesfrom fiddler_langgraph.tracing.instrumentation import add_span_attributesfrom fiddler_langgraph import add_span_attributes
      set_llm_contextfrom fiddler_langgraph.tracing.instrumentation import set_llm_contextfrom fiddler_langgraph import set_llm_context
      set_conversation_idfrom fiddler_langgraph.tracing.instrumentation import set_conversation_idfrom fiddler_otel import set_conversation_id
      Impact: Any of these imports using the fiddler_langgraph.tracing.instrumentation path will raise ModuleNotFoundError: No module named 'fiddler_langgraph.tracing' when upgrading to 1.4.2.
    • is_fiddler_span utility relocated to fiddler_otel.utils: The is_fiddler_span() function has moved from fiddler_langgraph.core.utils to fiddler_otel.utils. Update the import if you are using this utility directly. Old import (1.4.1 and earlier): 
      from fiddler_langgraph.core.utils import is_fiddler_span
      New import (1.4.2+): 
      from fiddler_otel.utils import is_fiddler_span
      Impact: Upgrading to 1.4.2 without updating the import raises ModuleNotFoundError: No module named 'fiddler_langgraph.core'.
  • New features (via fiddler-otel 1.1.0)
    • Offline / S3 routing mode: FiddlerClient now accepts two new parameters for writing traces to local files instead of sending them directly to Fiddler. This enables deployments where security or network policies require data to pass through a controlled intermediary (such as Amazon S3) before reaching Fiddler.
      ParameterTypeDefaultDescription
      otlp_enabledboolTrueSet to False to disable direct OTLP export. api_key and url are not required when False.
      otlp_json_capture_enabledboolFalseWhen True, writes traces to local .json files in standard OTLP JSON format (ExportTraceServiceRequest envelope) compatible with the Fiddler S3 connector.
      otlp_json_output_dirstr'fiddler_traces'Output directory for OTLP JSON files. Created automatically if it does not exist. Each span batch is written to a separate timestamped file.
      from fiddler_langgraph import LangGraphInstrumentor
from fiddler_otel import FiddlerClient

# No api_key or url needed — traces written to local files only
client = FiddlerClient(
    application_id='YOUR_APPLICATION_ID',  # Required — used by S3 connector to route traces
    otlp_enabled=False,
    otlp_json_capture_enabled=True,
    otlp_json_output_dir='./fiddler_traces',
)

instrumentor = LangGraphInstrumentor(client=client)
instrumentor.instrument()
# Traces are written to ./fiddler_traces/*.json — upload these files to S3
      See Offline / S3 Routing Mode in the integration guide for full details.
  • Documentation
    • Updated the LangGraph SDK integration guide to use LangGraphInstrumentor throughout — all code examples, quick start, configuration, and troubleshooting sections now reflect the new import path.
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1.4.1
Fiddler LangGraph SDK
March 20, 2026
  • Bug Fixes
    • Fixed set_conversation_id() ignored after first LangGraph invocation: When using LangGraphInstrumentor, calling set_conversation_id() between agent invocations had no effect — every span after the first run carried the conversation ID from the initial call. The root cause was a @cached_property on the internal _CallbackHandler that read the conversation ID contextvar once on first access and froze that value for the lifetime of the _CallbackHandler instance. The cached property has been replaced with a direct contextvar read on every span, matching the behaviour of FiddlerSpanProcessor. set_conversation_id() now takes effect immediately for all subsequent invocations.
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1.4.0
Fiddler LangGraph SDK
February 18, 2026
  • Added
    • Decorator-based instrumentation: New @trace() decorator for automatic function instrumentation.
      • @trace() decorator for instrumenting any Python function with minimal boilerplate.
      • get_current_span() to access the current span inside decorated functions.
      • Support for span types: span, generation, chain, tool, with type-specific wrappers and helpers (e.g. set_user_prompt(), set_tool_input()).
      • Automatic parent-child relationship from call stack.
      • Decorator arguments for metadata: model, system, user_id, version.
      • capture_input and capture_output arguments for controlling automatic argument/return value capture.
      • Automatic async function detection — @trace() works with both sync and async functions.
    • Manual instrumentation: Context managers and explicit control.
      • client.start_as_current_span(name, as_type=...) for context-manager usage with automatic lifecycle and exception recording.
      • client.start_span(name, as_type=...) for explicit control; caller must call span.end().
      • Support for all span types with both patterns.
    • Span wrapper classes: Typed wrappers with semantic convention helpers.
      • FiddlerSpan (base), FiddlerGeneration, FiddlerChain, FiddlerTool — returned by start_as_current_span(), start_span(), and get_current_span().
      • FiddlerGeneration helpers: set_model(), set_system(), set_user_prompt(), set_completion(), set_usage(), set_messages(), set_output_messages(), set_tool_definitions().
      • FiddlerTool helpers: set_tool_name(), set_tool_input(), set_tool_output().
      • Common helpers on all wrappers: set_input(), set_output(), set_attribute(), set_agent_name(), set_conversation_id().
    • Global client accessor: get_client() retrieves the active FiddlerClient singleton for use in decorators and utility functions.
    • Context isolation: Isolation from other OpenTelemetry tracers.
      • Each FiddlerClient uses its own isolated Context.
      • is_fiddler_span() utility to verify span ownership.
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1.3.1
Fiddler LangGraph SDK
February 5, 2026
  • Enhancements
    • Automatic Span Flush on Exit: FiddlerClient now registers an atexit handler to automatically flush and shut down the tracer provider when the process exits, reducing span loss from in-memory buffering.
    • Explicit Flush and Shutdown Methods: New force_flush(timeout_millis) and shutdown() methods on FiddlerClient for explicit control over span export. shutdown() is idempotent and safe to call multiple times.
    • Asyncio Support: New aflush() and ashutdown() async methods run flush and shutdown in a thread pool, avoiding event loop blocking in asyncio applications.
    • Context Manager Support: FiddlerClient can now be used as a context manager (with FiddlerClient(...) as client:) to ensure automatic shutdown on exit.
  • Bug Fixes
    • Fixed Pydantic Double-Encoding: Corrected JSON serialization of Pydantic models to use model_dump() instead of model_dump_json(), preventing double-encoded JSON strings in span attributes.
    • Deduplicated Retriever Span Attributes: Removed duplicate TYPE and TOOL_NAME attribute assignments in the on_retriever_start callback.
    • Replaced print() with logging: All print() calls in jsonl_capture.py now use the standard logging module for proper log management.
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1.3.0
Fiddler LangGraph SDK
January 21, 2026
  • Enhancements
    • OpenTelemetry Version Upgrade: Updated OpenTelemetry dependencies to version 1.39.1/0.60b1 for improved performance and compatibility:
      • opentelemetry-api: now supports up to 1.39.1
      • opentelemetry-sdk: now supports up to 1.39.1
      • opentelemetry-instrumentation: now supports up to 0.60b1
      • opentelemetry-exporter-otlp-proto-http: now supports up to 1.39.1
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1.2.0
Fiddler LangGraph SDK
January 14, 2026
  • Enhancements
    • Removed Hardcoded OpenTelemetry Limits: Removed hardcoded default values for span limits and batch span processor configuration. The SDK now relies on OpenTelemetry SDK’s built-in defaults, simplifying configuration and ensuring consistency with standard OpenTelemetry defaults.
    • Enhanced LangGraph Tracing with Full Message History: Introduced comprehensive message lifecycle tracking with two new span attributes:
      • gen_ai.input.messages: Captures the complete message history provided as input to the LLM, including system, user, assistant, and tool messages
      • gen_ai.output.messages: Captures the output messages generated by the LLM, including tool calls and finish_reason when available
      • Both attributes are aligned with GenAI semantic conventions for standardized observability
    • Extracted Message History from Strands Span Events: Added support for extracting gen_ai.input.messages and gen_ai.output.messages from Strands span events (emitted as events rather than attributes) and storing them as span-level attributes in ClickHouse for unified querying and analysis.
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1.0.0
Fiddler LangGraph SDK
December 6, 2025
  • Breaking Changes
    • Moved add_session_attributes to Tracing Module: The add_session_attributes() method has been relocated from the Core module to the Tracing module to co-locate session management functions with related tracing utilities.
      • Old import: from fiddler_langgraph.core.attributes import add_session_attributes
      • New import: from fiddler_langgraph.tracing.instrumentation import add_session_attributes
      • Migration: Update import statements in your code. No functional changes—all behavior remains identical.
      • Impact: Existing code using the old import path will fail with ImportError
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0.1.1
Fiddler LangGraph SDK
Previous Release
Initial release of Fiddler LangGraph SDK.