Fiddler LangGraph SDK

1.3

1.3.1

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.

1.3.0

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

1.2

1.2.0

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.

1.0

1.0.0

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

0.1

0.1.1

Previous Release

Initial release of Fiddler LangGraph SDK.