---
title: "WeaveConnector"
id: weaveconnector
slug: "/weaveconnector"
description: "Learn how to use Weights & Biases Weave framework for tracing and monitoring your pipeline components."
---

# WeaveConnector

Learn how to use Weights & Biases Weave framework for tracing and monitoring your pipeline components.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | Anywhere, as it’s not connected to other components                                                                                                                                                                     |
| **Mandatory init variables**           | `pipeline_name`: The name of your pipeline, which will also show up in Weaver dashboard.                                                                                                                                |
| **Output variables**                   | `pipeline_name`: The name of the pipeline that just run                                                                                                                                                                 |
| **API reference**                      | [Weave](/reference/integrations-weave)                                                                                                                                                                       |
| **GitHub link**                        | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/weave |
| **Package name** | `weave-haystack` |

</div>

## Overview

This integration allows you to trace and visualize your pipeline execution in [Weights & Biases](https://wandb.ai/site/).

Information captured by the Haystack tracing tool, such as API calls, context data, and prompts, is sent to Weights & Biases, where you can see the complete trace of your pipeline execution.

### Prerequisites

You need a Weave account to use this feature. You can sign up for free at [Weights & Biases website](https://wandb.ai/site).

You will then need to set the `WANDB_API_KEY` environment variable with your Weights & Biases API key. Once logged in, you can find your API key on [your home page](https://wandb.ai/home).

Then go to `https://wandb.ai/<user_name>/projects` and see the full trace for your pipeline under the pipeline name you specified when creating the `WeaveConnector`.

You will also need to set the `HAYSTACK_CONTENT_TRACING_ENABLED` environment variable set to `true`.

## Usage

First, install the `weights_biases-haystack` package to use this connector:

```shell
pip install weights_biases-haystack
```

Then, add it to your pipeline without any connections, and it will automatically start sending traces to Weights & Biases:

```python
import os

from haystack import Pipeline
from haystack.components.builders import ChatPromptBuilder
from haystack.components.generators.chat import OpenAIChatGenerator
from haystack.dataclasses import ChatMessage

from haystack_integrations.components.connectors.weave import WeaveConnector

pipe = Pipeline()
pipe.add_component("prompt_builder", ChatPromptBuilder())
pipe.add_component("llm", OpenAIChatGenerator())
pipe.connect("prompt_builder.prompt", "llm.messages")

connector = WeaveConnector(pipeline_name="test_pipeline")
pipe.add_component("weave", connector)

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"},
            "template": messages,
        },
    },
)
```

You can then see the complete trace for your pipeline at `https://wandb.ai/<user_name>/projects` under the pipeline name you specified when creating the `WeaveConnector`.

### With an Agent

```python
import os

# Enable Haystack content tracing
os.environ["HAYSTACK_CONTENT_TRACING_ENABLED"] = "true"

from typing import Annotated

from haystack.components.agents import Agent
from haystack.components.generators.chat import OpenAIChatGenerator
from haystack.dataclasses import ChatMessage
from haystack.tools import tool
from haystack import Pipeline

from haystack_integrations.components.connectors.weave import WeaveConnector


@tool
def get_weather(city: Annotated[str, "The city to get weather for"]) -> str:
    """Get current weather information for a city."""
    weather_data = {
        "Berlin": "18°C, partly cloudy",
        "New York": "22°C, sunny",
        "Tokyo": "25°C, clear skies",
    }
    return weather_data.get(city, f"Weather information for {city} not available")


@tool
def calculate(
    operation: Annotated[
        str,
        "Mathematical operation: add, subtract, multiply, divide",
    ],
    a: Annotated[float, "First number"],
    b: Annotated[float, "Second number"],
) -> str:
    """Perform basic mathematical calculations."""
    if operation == "add":
        result = a + b
    elif operation == "subtract":
        result = a - b
    elif operation == "multiply":
        result = a * b
    elif operation == "divide":
        if b == 0:
            return "Error: Division by zero"
        result = a / b
    else:
        return f"Error: Unknown operation '{operation}'"

    return f"The result of {a} {operation} {b} is {result}"


# Create the chat generator
chat_generator = OpenAIChatGenerator()

# Create the agent with tools
agent = Agent(
    chat_generator=chat_generator,
    tools=[get_weather, calculate],
    system_prompt="You are a helpful assistant with access to weather and calculator tools. Use them when needed.",
    exit_conditions=["text"],
)

# Create the WeaveConnector for tracing
weave_connector = WeaveConnector(pipeline_name="Agent Example")

# Build the pipeline
pipe = Pipeline()
pipe.add_component("tracer", weave_connector)
pipe.add_component("agent", agent)

# Run the pipeline
response = pipe.run(
    data={
        "agent": {
            "messages": [
                ChatMessage.from_user(
                    "What's the weather in Berlin and calculate 15 + 27?",
                ),
            ],
        },
        "tracer": {},
    },
)

# Display results
print("Agent Response:")
print(response["agent"]["last_message"].text)
print(f"\nPipeline Name: {response['tracer']['pipeline_name']}")
print(
    "\nCheck your Weights & Biases dashboard at https://wandb.ai/<user_name>/projects to see the traces!",
)
```
