Add comprehensive README

integrations/langfuse/README.md

@@ -1,22 +1,87 @@
-# langfuse
+# langfuse-haystack
 
 [![PyPI - Version](https://img.shields.io/pypi/v/langfuse-haystack.svg)](https://pypi.org/project/langfuse-haystack)
 [![PyPI - Python Version](https://img.shields.io/pypi/pyversions/langfuse-haystack.svg)](https://pypi.org/project/langfuse-haystack)
 
------
+langfuse-haystack integrates tracing capabilities into [Haystack](https://github.com/deepset-ai/haystack) (2.x) pipelines using [Langfuse](https://langfuse.com/). This package enhances the visibility of pipeline runs by capturing comprehensive details of the execution traces, including API calls, context data, prompts, and more. Whether you're monitoring model performance, pinpointing areas for improvement, or creating datasets for fine-tuning and testing from your pipeline executions, langfuse-haystack is the right tool for you.
+## Features
 
-**Table of Contents**
-
-- [langfuse](#langfuse)
-  - [Installation](#installation)
-  - [License](#license)
+- Easy integration with Haystack pipelines
+- Capture the full context of the execution
+- Track model usage and cost
+- Collect user feedback
+- Identify low-quality outputs
+- Build fine-tuning and testing datasets
 
 ## Installation
 
-```console
+To install langfuse-haystack, simply run the following command:
+
+```sh
 pip install langfuse-haystack
 ```
 
+## Usage
+
+To enable tracing in your Haystack pipeline, you need to add the `LangfuseComponent` to your pipeline. Here's an example:
+
+```python
+import os
+
+os.environ["LANGFUSE_HOST"] = "https://cloud.langfuse.com"
+os.environ["TOKENIZERS_PARALLELISM"] = "false"
+os.environ["HAYSTACK_CONTENT_TRACING_ENABLED"] = "true"
+
+from haystack.components.builders import DynamicChatPromptBuilder
+from haystack.components.generators.chat import OpenAIChatGenerator
+from haystack.dataclasses import ChatMessage
+from haystack import Pipeline
+
+from haystack_integrations.components.others.langfuse import LangfuseComponent
+
+if __name__ == "__main__":
+    pipe = Pipeline()
+    pipe.add_component("tracer", LangfuseComponent("Chat example"))
+    pipe.add_component("prompt_builder", DynamicChatPromptBuilder())
+    pipe.add_component("llm", OpenAIChatGenerator(model="gpt-3.5-turbo"))
+
+    pipe.connect("prompt_builder.prompt", "llm.messages")
+
+    messages = [
+        ChatMessage.from_system("Always respond in German even if some input data is in other languages."),
+        ChatMessage.from_user("Tell me about {{location}}"),
+    ]
+
+    response = pipe.run(
+        data={"prompt_builder": {"template_variables": {"location": "Berlin"}, "prompt_source": messages}}
+    )
+    print(response["llm"]["replies"][0])
+    print(response["tracer"]["trace_url"])
+```
+
+In this example, we add the `LangfuseComponent` to the pipeline with the name "tracer". Each run of the pipeline produces one trace viewable on the Langfuse website with a specific URL. The trace captures the entire execution context, including the prompts, completions, and metadata.
+
+## Trace Visualization
+
+Langfuse provides a user-friendly interface to visualize and analyze the traces generated by your Haystack pipeline. Simply login into your Langfuse account and navigate to the trace URL to view the trace details.
+
+## Contributing
+
+`hatch` is the best way to interact with this project, to install it:
+```sh
+pip install hatch
+```
+
+With `hatch` installed, to run all the tests:
+```
+hatch run test
+```
+
+To run the linters `ruff` and `mypy`:
+```
+hatch run lint:all
+```
+
 ## License
 
-`langfuse` is distributed under the terms of the [Apache-2.0](https://spdx.org/licenses/Apache-2.0.html) license.
+`langfuse-haystack` is distributed under the terms of the [Apache-2.0](https://spdx.org/licenses/Apache-2.0.html) license.