> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Complete API reference for fiddler-otel

[![PyPI](https://img.shields.io/pypi/v/fiddler-otel)](https://pypi.org/project/fiddler-otel/)

## Overview

Complete API reference documentation for the `fiddler-otel` package, the
framework-agnostic OpenTelemetry-based instrumentation layer for any
Python LLM or agent application. `fiddler-otel` is the canonical source
for Fiddler's span attributes, conversation tracking, and span processing
primitives; the LangChain, LangGraph, and Strands SDKs build on top of it
and re-export several of its symbols.

```bash theme={null}
pip install fiddler-otel
```

```python theme={null}
from fiddler_otel import FiddlerClient, trace
```

## Components

### Attributes

Span and resource attribute helpers. `set_conversation_id` and `add_session_attributes` are propagated through the current trace context; `FiddlerSpanAttributes`, `FiddlerResourceAttributes`, and `SpanType` enumerate the constant keys Fiddler recognizes.

* [add\_session\_attributes](/sdk-api/otel/add-session-attributes)
* [FiddlerResourceAttributes](/sdk-api/otel/fiddler-resource-attributes)
* [FiddlerSpanAttributes](/sdk-api/otel/fiddler-span-attributes)
* [set\_conversation\_id](/sdk-api/otel/set-conversation-id)
* [SpanType](/sdk-api/otel/span-type)

### Client

Client initialization and configuration. `FiddlerClient` wires the OTLP exporter, span processor, and resource attributes into the global tracer provider; `get_client` returns the active singleton.

* [FiddlerClient](/sdk-api/otel/fiddler-client)
* [get\_client](/sdk-api/otel/get-client)

### Decorators

Function-level tracing helpers. `@trace` instruments arbitrary Python functions; `get_current_span` returns the active span for attribute mutation inside a traced call.

* [get\_current\_span](/sdk-api/otel/get-current-span)
* [trace](/sdk-api/otel/trace)

### JSONL Capture

JSONL span exporter for offline analysis. Writes a structured trace record per span to a local file alongside (or instead of) OTLP export, useful for debugging and reproducing customer issues.

* [JSONLSpanExporter](/sdk-api/otel/jsonl-span-exporter)

### Span Processor

Custom OpenTelemetry span processor that enriches outgoing spans with Fiddler resource attributes before export.

* [FiddlerSpanProcessor](/sdk-api/otel/fiddler-span-processor)

### Span Wrapper

Manual span creation primitives for code paths that don't fit the decorator model. `FiddlerSpan` is the base; `FiddlerChain`, `FiddlerGeneration`, and `FiddlerTool` carry semantic conventions for retrieval/agent steps, LLM calls, and tool invocations.

* [FiddlerChain](/sdk-api/otel/fiddler-chain)
* [FiddlerGeneration](/sdk-api/otel/fiddler-generation)
* [FiddlerSpan](/sdk-api/otel/fiddler-span)
* [FiddlerTool](/sdk-api/otel/fiddler-tool)